8.9 Photographing Warblers

A number of bird families deserve special consideration as to the mechanics of their effective capture (photographically) in the field.  One of these is the warblers.  Though the taxonomists will rightfully distinguish between the old-world warblers (the Sylviidae) and the new-world warblers (the Parulidae), for our purposes it serves just as well to consider any small, fast-moving bird as an honorary warbler—just for the present discussion.  These subjects can be exceedingly difficult to capture in an aesthetic pose, for a number of reasons which we’ll consider in due course.  In this section we’ll focus on techniques for effectively photographing small, active songbirds such as warblers, vireos, wrens, chickadees, nuthatches, and similar species.
    For many birders, the biggest problem with warblers is finding them and getting close enough to get a good view (and/or a good photograph).  In the suburbs of Washington D.C., where I first took up birding many years ago, there are a number of excellent places to go to see warbers during the spring migration.  Unfortunately, these tend to be better places to see warblers (i.e., with binoculars) than to photograph them.  In many forest settings, warblers like to forage high in the trees, and since the birds are themselves quite small, an enormous amount of magnification may be required to make the bird fill enough of the frame. 

Fig. 8.9.1: One of the biggest problems in warbler photography is getting the bird
to be large enough in the frame.  Though longer focal-length lenses can help, a
better option is to get closer to the bird, if you can.  Note that not all warbler
photos have to have a bird large in the frame.  If the background is nice enough,
the bird can be quite small and still result in an interesting image.  My personal
preference, though, is for the bird to be bigger in frame than shown here.

    My first serious attempt at photographing warblers was along the Eno River in North Carolina, using an 800mm f/5.6 tripod-mounted lens.  After upgrading from a consumer-grade 400mm zoom lens, I felt sure this would provide enough firepower to capture any bird I wanted.  My preferred prey at that time was the Yellow-throated Warbler (Dendroica dominica), which in this area likes to forage at the tops of very tall sycamore trees.  Discovering that my tripod head wouldn’t tilt back far enough to point straight up, I took to lying on my back on the forest floor with the lens—still attached to the tripod—balancing uncomfortably on top of my face.  While the birds frolicked high above, I did my best to track them with my monstrous lens positioned vertically from the forest floor below.  The top image in the figure below shows a typical result of these early attempts.  As you can see, it’s not very good.

Fig. 8.9.2: Magnification versus closeness.  Top: even using an 800mm lens, I was
unable to get decent images of yellow-throated warblers (Dendroica dominica)
foraging high in the trees above me.  Bottom: when the bird came down to my
level, I was able to get a much better shot using a lightweight 400mm lens.

    The problem is that for birds high in the trees, even with an 800mm lens you’ll typically need to crop the image very, very aggressively in order to enlarge the bird.  Even after aggressive cropping, the top image in the above photo still features a small bird in the frame, and the sharpness is obviously quite awful.  After several days of strenuous effort at photographing these birds with the monstrous 800mm lens, I got lucky.  While walking back to my car one morning an individual came down to perch briefly at my level.  I quickly set down my tripod-mounted rig and switched to my shoulder camera, on which I keep a 400mm lens mounted.  I then shot the bottom image shown in the figure above.
    The moral of this story is that you can spend inordinate amounts of time, money, and effort trying to achieve the impossible—in this case, obtaining tack-sharp images of tiny birds flitting energetically through the treetops high above—or you can instead opt for patience and adopt an opportunistic strategy, capturing birds at close range when they decide to come into close range.  For birders just starting out with photography, it can be difficult to have this kind of patience, but doing so can help to save wasted time and effort obtaining poor-quality photos that later will be supplanted with much higher quality images obtained—in time—through opportunism, continual readiness, and good old-fashioned luck.

Fig. 8.9.3: When shooting warblers foraging in the branches above you, what you’re
most likely to get are belly shots.  Although belly shots can occasionally be interesting,
they lose their novelty after you’ve taken several million of them.  Not all shots of
warblers overhead need be belly shots, however, since the birds tend to be quite

    It turns out that luck can often be manipulated through intelligent planning.  In the case of warbler photography, there are a number of hotspots that, if you’re there at the right time of year, can yield photographic opportunities that are simply impossible in most photographers’ home towns.  In 2008 I spent a solid month (late April and early May) pursuing warblers at my local state park, acquiring in the process a handful of moderately acceptable images, though nothing exceptional.  In mid-May of the same year I spent ten days at a warbler hotspot in Ohio, where I effortlessly shot thousands of photos of warblers at virtually point-blank range as they foraged mere feet from where I was standing. 

Fig. 8.9.4: A belly shot that I like.  Though the image lacks
sharpness, I like the dreamy quality of the background.  As
far as belly shots go, this one at least gives you a glimpse
of the bird’s face, though most photographers would discard
this image because of the angle (i.e., shot from below).

    I now make it a yearly ritual to travel to the same warbler hotspot for 10 days of intense shooting, which allows me to prioritize my efforts at home, during the remainder of spring, toward those few species that are easier to shoot locally where I live (such as the Prairie Warbler, Dendroica discolor).  Traveling to a remote location to shoot birds can indeed be costly and inconvenient (and even dangerous), but can be extremely efficient in terms of expenditure of time.  Knowing that you can easily capture species X, Y, and Z during a remote vacation will free you to concentrate on other species that are easier to capture in your own locale during the rest of the year.
    In terms of warbler photography in the United States, there are several sites that stand out head-and-shoulders above the rest.  These are Magee Marsh in Ohio, Point Pelee in Ontario, Dauphin Island in Alabama, High Island in Texas, and the Dry Tortugas off the southern tip of Florida.  I have experience only with two: Magee Marsh in Ohio, which is pictured below, and Dauphin Island, which I've visited only once (in early April) and where I unfortunately saw very few birds.

Fig. 8.9.5: The warbler mecca known as Magee Marsh.  On a good day at Magee
in mid-May you can see hundreds of warblers at close range.  I don’t even bother
trying to shoot certain warbler species in my home town anymore, since I go to Magee
every spring.  Other warbler meccas include Point Pelee, Dauphin Island, and the Dry Tortugas.

    Magee Marsh (formerly known as Crane Creek State Park) is without a doubt my all-time favorite birding location.  Though it has its slow days even during mid-May (traditionally the peak time for warbler fallouts at this site), the good days at Magee more than make up for the bad days.  As with any migrant trap, it’s highly recommended that you plan to spend more than just a couple of days there, to improve your chances of being present when a big wave hits.  Prominent birders who are local to these sites will often provide educated guesses and predictions as to when a big wave of migrant birds will likely arrive, and these can be useful in planning a trip to these locations, though much depends on the weather and is therefore subject to change at the last minute.  A week to ten days is a good amount of time to budget for a trip to a warbler migration hotspot such as Magee Marsh in Ohio or Point Pelee in Ontario.
    If you do visit a major migrant trap in spring, there are a number of things you can do to improve your productivity.  First, it can be extremely useful to be able to recognize individual bird species by their songs—i.e., to
bird by ear.  Being able to recognize bird species by their songs allows you to do several things.  First, when you hear a bird singing that you can’t yet see (because it’s behind too many leaves), you can decide whether this is a species of special interest to you, or if instead it’s one that you’ve already got too many images of.  The other thing that birding by ear does is to widen your field of attention.  When you don’t know your bird songs, any individual song you hear just sounds like background chatter in the forest.  But when you know your songs, hearing a familiar song can force you, subconsciously, to become more aware of the birds that are in your immediate vicinity.  In other words, just knowing the songs can help you to be more attentive, which can in turn help you to find the birds more easily.

Fig. 8.9.6: The author enjoying himself on the boardwalk at Magee.
There is something truly special about photographing warblers here.

    Visiting a warbler hotspot during the peak migration period is an exciting experience.  At Magee Marsh in mid-May, there are often hundreds of birders present on the boardwalk at any given time.  Those hundreds of eyes all simultaneously searching for birds in the surrounding foliage are, in aggregate, far more efficient at finding good photographic opportunities than you alone will ever be.  This is something that you should be prepared to exploit to the greatest possible extent.  Remember that these birds are tiny, and even at a warbler hotspot there will be many individual birds that you’ll miss, even when they’re only thirty feet from where you’re standing.  If you factor in weather conditions such as wind, it’s clear that any help you can get from other birders in just finding the birds can be extremely valuable.
    Not all information from other birders is of equal value, however.  For example, many birders will become excited about a rare species that they can just barely make out through their 10
× binoculars at a large distance, in the deep shade of a bush blowing in high wind.  These are generally very poor photographic opportunities, unless you’re specifically trying to get photos of these rare species for documentation purposes.  Whenever I come upon a congregation of birders all looking through their binoculars, I take note of several things.  First, if all the binoculars are pointed up at an extreme angle, that means the bird is probably high in a tree and will present only a belly shot.  In those cases I just keep walking until I come to the next group of birders.  Alternatively, if I hear one birder explaining to another in very detailed terms how to find the bird in his or her binoculars (e.g., follow the main branch up until it forks, and then look under the seventh twig for where the vine leads off into the distance, where the bird is partially visible...), then I keep walking right on by that group without even slowing down. 

Fig. 8.9.7: Connecticut warbler (Oporornis agilis).  I generally avoid
chasing rarities like this, since the time spent chasing one elusive bird
could be spent photographing ten less elusive birds.  But to each his own.

    It’s an interesting and often useful fact that at some migrant traps where individual birds may stop over for several days to refuel for their journey, you can end up seeing the same individual foraging in the same general vicinity—sometimes even in the same tree—day after day, or at least sporadically throughout a single day.  Another thing to keep in mind is that an inordinate amount of attention is typically dedicated by birders to the rarest species sighted at these locations.  The mourning warblers at Magee Marsh are a case in point.  Every year the boardwalk gets choked by crowds of birders eagerly trying to see a mourning warbler that was sighted off in the distance an hour ago.  If this species happens to be high on your priority list, then spending several hours waiting for the bird to make a brief appearance may be worthwhile for you.  Personally, I prefer to spend that time taking more photos of common species, so that I’ll have a wider variety of images to choose from later when I separate out the best photos from my trip.  Similarly, every year a report is made of a Kirtland’s warbler that has been spotted somewhere at Magee within the park or on the beach nearby, and many people flock to these sites to try to catch a glimpse of the bird.  I’ve found that chasing rarities like this is typically unproductive—for me, personally—given that my own personal goals are to simply obtain aesthetically pleasing images of birds of any species.  In the time that I might spend chasing a single rare bird, and getting either no photos of it or a few mediocre ones, I might instead be able to get a good number of very decent shots of some slightly less rare species.  These types of decisions depend of course on your personal goals, and on how extensive your portfolio has already become.
    Note that the ideal focal length—i.e., magnification—can be highly dependent on location, and this is a very important fact when considering a trip to a warbler hotspot.  While 800mm is barely enough (or more often not enough) at my local state park in North Carolina, at Magee Marsh in Ohio I find that the ideal focal length is between 400mm and 560mm (i.e., 400mm with a 1.4
× teleconverter attached) when shooting on the boardwalk, where the warblers will often come to within ten feet of you while frantically chasing insects.  Indeed, many photographers have found that using a 500mm or 600mm tripod-mounted lens on the boardwalk at Magee can be counterproductive, both due to the crowds of people that the heavy equipment has to be carted through, and the fact that the birds often get so close that these bigger lenses can’t even focus on them.  At Magee Marsh the most popular lens is the Canon 100-400mm f/5.6 zoom.  Many birders have captured exquisite images at these modest focal lengths at this site, making the trip from their home states overwhelmingly worthwhile for them.

Fig. 8.9.8: Focal length can be your friend or your enemy.  Though
excessive magnification can produce truly stunning
macro views that
you might not be able to otherwise get in the real world, it also reduces
your options for framing the bird.  Also, larger focal-length lenses tend
to have larger close-focus distances, which can prevent you from taking
the shot when the bird gets too close (as is common at some warbler hotspots).

    Let’s now move on to some more technical issues, starting with the framing of the bird.  This is something that magnification—i.e., focal length—can impinge upon fairly directly.  When you have the option to do so, filling most of the frame with the bird can result in truly stunning degrees of detail and color range.  Artistically, these macro shots may or may not satisfy your photographic goals, depending on the resulting geometry, foreground-background apportioning, and color composition.  Macro shots of warblers can be very well received by general viewers, though they can also become a bit monotonous when overdone. 
    For those with high-powered optics in prime warbler photography locations, it’s definitely worth considering smaller focal lengths.  A smaller focal length will necessarily trade off bird detail for perspective and background inclusion.  A nice, colorful background is often what is most needed to turn a good warbler photo into a great warbler photo.  Remember that the bird lives in a particular environment, and your viewer doesn’t necessarily know much about that environment.  Furthermore, these are extremely small birds living at relatively small scales (when they’re not migrating across thousands of miles).  The world of the bird becomes particularly relevant when the scales of the subject and its ecologically immediate environment are substantially different from the fundamental scale of the human viewer.  To the extent that you can effectively capture that scale difference while retaining a compositionally coherent image, you’ve satisfactorily exploited the imaging potential of that scene.

Fig. 8.9.9: Getting a good background in a warbler photo can be difficult. 
Most warblers bathe regularly, typically around late morning or mid-day.
Staking out a clean pool of water at a warbler hotspot can be good way
to widen the range of backgrounds in your photos.

    Good backgrounds in warbler photos can be very difficult to obtain.  In practice, because the birds tend to move so quickly, often the best you can do is to take at least one shot of the bird every time it moves to a new perch, and to hope that at least one of the shots features a decent background.  Remember that many backgrounds can be improved in Photoshop with fairly minimal effort, such as through artificial blurring (section 12.6).  The prime issue then becomes the proportion and arrangement of space around the bird, and this is something you need to be cognizant of while shooting in the field.  Whenever the bird becomes so big that it’s difficult to place a comfortable margin around the subject in the viewfinder, I generally try to move back, away from the subject, to widen the field and increase the amount of background space I’ll have to work with later during post-processing.  A good rule of thumb is to try to ensure that the bird takes up no more than half of the space in the horizontal or vertical directions, when shooting in the field; while this may seem a rather useless rule in many locations where the birds never get very close, in birding hotspots it can indeed become relevant on a daily basis.  At these sites you may indeed find more utility in a 100-400mm zoom lens than in a 500mm or 600mm prime, since you can easily zoom out as needed to give the bird some space in the frame.
    In terms of which types of backgrounds are more aesthetic than others, this is something that can be difficult to assess in the field.  I personally try to avoid excessively dark backgrounds, because they often appear black in the captured image, and too many of these low-key images gets to be either cliché or simply monotonous.  In the field you’ll often find that taking just one step to the left or the right can dramatically alter the background as seen through the viewfinder.  It always surprises me how a tiny change to the angle of the lens can result in such a significant change in the overall background composition.  Things like tree trunks, vines, and leaves dangling behind the bird will start to catch your attention more as you gain experience with photographing small birds.  For example, when using flash, a tree trunk immediately behind the bird is usually (though not always) a Bad Thing, because it’ll often show up in the final image as a bright gray band enclosing the bird. 
With experience you’ll develop your own intuition for what types of background elements—and at what distances behind the bird—can potentially enhance or mar a warbler photo.

Fig. 8.9.10: Dark backgrounds sometimes help to make the bird look more
prominent in the scene, though too many dark backgrounds in a single gallery
gets to be monotonous.  In this photo I liked the way the diagonal band of green
breaks up the darkness behind the bird, while natural sunlight falling exactly
on the bird helped to make the subject stand out even more.  Warbler photos
like this are rarely planned—you just have to take whatever you can get
in the field and then sort through your images later for the lucky shots.

    Camera settings can of course modulate the effect of the background in significant ways.  If the aperture is too small, for example, foliage too close behind the bird can form distracting patterns that you’ll later want to fix in Photoshop (see section 12.6).   If you know á priori that you won’t have time to perform such detailed manipulation in post-process, then you might decide to forego taking such photos in the first place.  Keep in mind also that your flash ratio (section 7.6) can strongly affect the prominence of the background in the final image. 

Fig. 8.9.11: Small apertures can result in distracting backgrounds,
due to a wide depth of field (DOF), though at any DOF you can still
end up with too much background detail if the bird is flanked closely
by foliage.  These issues can be corrected later in Photoshop by
separating the bird from the background and applying a blur
filter to the background to reduce detail (not shown here).

Flash ratio can indeed be a very useful parameter to adjust in the field, since it can sometimes help to improve color in the background when desired.  When the backdrop of the bird is some distance behind the subject, increasing the ratio of ambient light to flash can help to bring out more background color, whereas for backdrops close to the bird, a stronger flash may instead be indicated so as to better illuminate the background via flash light rather than ambient. 
    Just remember that the effect of the flash output on the subject is typically your primary concern.  In the case of warblers, the use of flash to induce micro-contrast (section 4.3) can be a highly effective technique for bringing out more detail in these tiny birds, especially when magnification is not on your side.  As we’ll discuss shortly, the ability of short flash durations—and high flash ratios—to freeze action can also be useful in the field, and needs to be considered when choosing a flash setting.  Many of these tradeoffs can be efficiently explored in the field by taking several rapid shots of the bird at different settings and assessing the results on your camera’s LCD, so don’t feel that the situation is hopelessly complicated by all of these varied considerations.

Fig. 8.9.12: A detailed foreground and a blurred background can help to make your
subject stand out.  Though sharpening was applied to this bird in Photoshop, much of
the apparent detail comes from micro-contrast, which results from strong directional
light.  The background was slightly blurred in Photoshop using the Reduce Noise filter.
Since warblers are so small and spend so much time in thick foliage and other dense
micro-environments, any trick you can use to make them stand out from their background
can be highly useful in producing a memorable image.

    More generally, the task of choosing appropriate exposure parameters when shooting warblers can be a bit of a challenge in some situations.  It’s therefore worth revisiting some of the material from Chapters 6 and 7 and refining things a bit to make them more applicable to the case of small, fast-moving subjects at intermediate distances.  We’ll do that next.  Much of what we’ll discuss assumes you’re shooting in manual exposure mode, which I highly recommend.
    First, let’s consider the aperture.  Not only does the aperture affect depth of field, but the effect of aperture on depth of field is distance-dependent: subjects that are further from the camera will enjoy a correspondingly greater depth of field (see sections 3.1 and 6.1).  When shooting warblers at a major migrant trap, the distances are often quite small, so that depth of field ends up suffering.  The figure below shows a Prothonotary warbler shot at 840mm with an aperture of f/5.6, with the subject being rougly 15 feet from the objective lens.  At this distance and aperture, the depth of field for this camera’s pixel pitch is literally on the scale of mere inches.  As a result, you can see in the figure below that only the bird’s head is in focus, while the rest of the body blurs into the distance.

Fig. 8.9.13: Depth of field can be your friend or your enemy.  Though a
shallow DOF can help to isolate the bird from its background, at close
range the razor-thin depth of field can result in only part of the bird being
in focus.  In this example the head was perfectly in focus, so the shallow
DOF was acceptable, but if your camera decides to focus instead on
the bird’s wing or tail, a shallow DOF can ruin the image.

     For warbler photography, a shallow depth of field (DOF) may indeed be what is desired for particular subjects in particular scenes.  When the bird is large in the frame, a shallow DOF helps to isolate the bird’s head, eyes, and beak, which are typically the prime focal regions for human observers.  Artistically, shallow DOF’s are often a strength rather than a liability.  It’s still useful to keep in mind how DOF changes with aperture and distance-to-subject, however.  In the figure above only part of the bird was in focus, because the DOF was shallow and the bird was oriented along the lens axis.  For the figure below, the subject was instead oriented along an axis almost perpendicular to the lens, so that more of the bird remains in sharp focus, while the background is fairly blurry.  Whenever you’re shooting small birds at close range, keep in mind that perpendicular birds will separate much more readily from the background than birds oriented axially with the lens, and this can both affect the photo’s raw aesthetics and potentially simplify the task of post-processing the image.

Fig. 8.9.14: Subjects that are perpendicular to the line of sight (i.e., are in profile)
are easier to isolate via a shallow depth-of-field.  Such poses also simplify focusing;
with a warbler in strict profile, focusing on any part of the bird should cause the
eye to be in focus as well (assuming a perfectly flat bird...).

    Shutter speed is another important exposure parameter that needs to be considered carefully when shooting warblers.  These tiny birds can move very fast indeed, even when they’re not flying.  I’ve found that shutter speeds of 1/1600 sec can be too slow to freeze the head movements of a warbler frantically foraging at a migration stopover.  Using shutter speeds in excess of this tends to be problematic, however, because exposures tend to get rapidly darker, and the tendency to rely on higher (and noisier—see sections 2.5 and 11.1) ISO values becomes ever greater.
    I therefore tend to stick to the relatively slow
sync speed of my camera—i.e., 1/300 sec for the Canon 1D Mark III—since it maximizes effective flash output while still allowing sharp images to be captured in high ambient light when the bird is relatively still.  Since the shutter speed is then fixed, I only have to worry about the ISO setting, the aperture, and the flash power.  The aperture I typically leave fixed at 2/3 of a stop to 2 stops below maximum aperture, to maximize the sharpness of my lens without sacrificing too much light.  That leaves the ISO and flash power, and these are generally all that I modify when shooting warblers. 
    Balancing these two parameters allows me to adjust the flash ratio (section 7.6), which is of prime importance in getting a good exposure of both the bird and the background.  When the background is far behind the bird, some ambient light is needed to illuminate it, so that you don’t end up with a solid black background (figure 8.9.10 above shows a bird with a poorly lit background, due to a high flash ratio).  When the background is close behind the bird, strong flash can illuminate the background instead; this allows a high flash ratio to be used, which can be helpful in freezing the bird’s movements.  Getting the right flash ratio is tricky, however, and there are a few things worth repeating from previous chapters in this regard.

Fig. 8.9.15: A high flash ratio can help to freeze any motion that occurs
when the shutter is open.  In this case, the motion was mostly frozen, though
the shadows/ghosts surmounting the wings, beak, and cap attest to a non-
negligible amount of ambient in the mix.  Action shots of warbler are of course
fortuitous; rarely can a photographer take credit for having planned such a capture.

    First, recall that flash illumination is, unlike ambient light, distance-dependent.  That means that every time the bird moves closer to you, you need to consider reducing your flash power (assuming that you’re using manual flash rather than TTL flash).  When working at short distances, I set my flash power at 1/32 initially, and adjust upward or downward from there, whereas at longer distances I start at 1/4 and try not to go higher than 1/2 (to avoid short recycle times—see section 4.3 and Chapter 7).  At longer distances, a flash extender (section 7.9) is essential; at shorter distances, you may want to remove the extender to avoid disproportionately lighting up part of the bird or scene. 
    In addition to checking your LCD’s highlight alerts for overexposure (section 6.2), you also need to be careful not to induce feather glare due to overstrong flash.  Unfortunately, feather glare isn’t always obvious on the LCD, so it’s sometimes good to be conservative in the use of flash, especially at close distances.  Although microscopic amounts of feather glare can sometimes enhance an image via the phenomenon of micro-contrast (section 4.3), larger amounts of glare are to be avoided whenever possible, because it can be very difficult to fix in post-process (see sections 11.2 and 11.3).  Glare can do two things: it can bleach the colors out of your subject by overloading it with too many photons (so the feather surface can’t absorb the photons of the wrong color and reflect only those of the right color), and it can also potentially cause clipping in specific color channels in your sensor, which may not trigger your camera’s highlight alerts (unfortunately).  The figure below illustrates both of these problems.  The bird’s shoulder exhibits some feather glare that bleaches out some of the blue color, while the yellow regions lack detail in some areas due to clipping in the yellow

Fig. 8.9.16: Flash is invaluable for warbler photography, but must be used with
caution.  This figure illustrates two dangers of flash: feather glare, and clipping
of individual color channels.  Both are difficult to diagnose in the field, so it’s
best to be conservative in your use of flash for close-quarters warbler encounters,
at least until you’ve become experienced enough to quickly identify subtle
problems like these in the field.

     Fixing glare in post-process can be very difficult (see section 11.2 and 11.3), so it’s best to prevent it from happening in the first place.  Just keep in mind that your camera’s highlight alerts may not be showing you any clipping that occurs in individual channels.  On my camera, I find that birds with bright red or yellow plumages often suffer clipping in the red channel, even when the overall histogram shows no clipping (i.e., the highlight alerts don’t blink).  For that reason, whenever I’m photographing a bright red bird I always turn down the exposure a few clicks more than I normally would.  And for any bird that I’m photographing at close distance with a 400mm lens, I generally turn down the flash a few clicks (thirds of a stop of light) below what appears to be ideal based on the camera’s LCD.  These types of ad hoc adjustments tend to be camera-model dependent, so what works best for me might not work best for you.
    Another consideration with flash is that it can occasionally scare off the bird.  I’ve found that this occurs much less often than I originally expected it might, and far less often than some non-photographers have rudely insisted it would.  What I typically find with warblers is that a bird may be visibly startled by the first one, two, or three flashes, but that after that it will usually ignore the flash henceforth.  If the bird doesn’t fly away immediately after the first flash (which does happen in a small fraction of cases), it’s unlikely to do so after a few more.  At warbler hotspots where many photographers gather in spring, the birds tend to become insensitive to flash very, very quickly. 
    As a case in point, the Prothonotary Warbler shown in Figure 8.9.13 (four figures prior) was photographed at Magee Marsh during the second week of May, 2010.  This bird had a nest cavity next to the boardwalk where hundreds of people passed by each day.  At the time that particular photo was taken, the bird had just finished preening for a full five minutes in front of a group of about twelve photographers, all shooting through enormous lenses with powerful flash units attached.  The bird was about fifteen feet from the edge of the boardwalk, and was illuminated almost continuously by the flash pulses from the ecstatic photographers, never once batting an eye in our direction. 
The bird simply did not care about flash, and the vast majority of birds I’ve photographed appeared to have the same attitude.

Fig. 8.9.17: Another action shot enabled by the use of a short
flash duration and moderately high flash ratio.  The wing
blur is again due to ambient ghosting.  This shot was not planned.

    When shooting with flash there are a few mundane but still important things you might want to keep in mind.  First, because flash units eat batteries faster than Homer Simpson can eat doughnuts, it’s a good idea to enable the
auto-off feature of your flash unit, so that it turns itself off automatically after some period of disuse (say, two minutes, or five minutes).  If you do use this feature, you’ll likely find that when you suddenly try to take a photo of a bird that has appeared out of nowhere, the first shot ends up being underexposed because the flash unit’s capacitors didn’t have time to fully charge before you took the shot.  For most cameras and flash units, if you press any button on the camera while the flash is asleep, the unit will immediately wake up and begin to charge its capacitors in preparation for an impending discharge.  I take advantage of this by pressing the ISO button on my camera whenever a bird suddenly appears on the scene.  This wakes my flash unit, which should then have enough time to charge for the next shot before I myself am actually ready to press the shutter release.  Although I choose to use the ISO button for this purpose, just about any button on my camera will do.  Note, however, that waking your flash unit by lightly touching your shutter release is not the best solution, because doing so will activate your autofocus (unless you’ve reprogrammed your camera to use a separate AF on button), and if your camera isn’t yet pointing at the subject, this may result in slower acquisition of the focus later when you’re finally ready to acquire the subject and begin shooting.
    Another thing to keep in mind is that if you use the spray-and-pray technique
(section 6.6) of holding down the shutter release and taking a series of rapid-fire shots, the first photo may be differently exposed from subsequent photos, since the flash’s capacitors may not have time to recharge fully between shots.  Your camera or flash unit may have a special setting that you can use that deals with rapid-fire flash shots, but in general you’ll still be faced with lower flash output for fast-paced shooting.  One thing you can do to mitigate this effect is to turn down the flash power right from the outset, so that the first burst doesn’t fully empty the capacitors.  In many circumstances this isn’t ideal either, because the resulting flash output ends up being less than you’d like.  This is why for warbler photography I generally don’t use spray-and-pray.  One exception is if I decide to turn on the high-speed drive mode in order to take two shots per press of the shutter release.  Some photographers use this technique extensively, with the rationale that if the first photo of the pair is blurry due to subject movement, the second might not be.  I rarely use this technique, but it is worth considering if you’re getting lots of blurry shots of a restless subject.

Fig. 8.9.18: Intentionally capturing a warbler in flight is a skill reserved for true masters
of bird photography.  Until I become one of those, I’ll instead rely on dumb luck, as in this case.

    Note that for warbler photography you’ll often want to keep IS (image stabilization—section 3.5) turned off.  These birds simply move too fast for IS to be useful.  For in-the-lens IS (still the most popular and most effective form of IS), the gyroscope used to achieve stabilization takes some time to start spinning and then to reach its terminal velocity, and meanwhile the autofocus system is either waiting for the signal from the IS system that stabilization has been achieved, or (conceivably in some systems) has already started trying to autofocus before the image is stabilized.  In either case, autofocus acquisition speed is very likely to suffer as a result of the IS being enabled (as I’ve discovered is certainly the case with my camera and lens).  Because warblers tend to move around so much, IS makes little sense anyway, since it can work against you as you try to pan the lens to follow the bird (unless you’re using IS in panning mode—see section 3.5). 
    Now let’s consider in greater detail the challenges of properly exposing a typical warbler.  The attraction of shooting warblers is, for many, the birds’ varied color.  As illustrated by the chestnut-sided warbler shown below, they often contain both white and black plumage elements, and can also sport yellows, reds, and other hues.  For birds having both whites and blacks (or, more generally, very light and very dark colors), properly exposing both extremes is rarely easy. 

Fig. 8.9.19: Exposing whites in warblers can be difficult.  I recommend using the ETTR
philosophy, by exposing as bright as possible without clipping the highlights.  The use of
flash can also help tremendously, due to the phenomenon of micro-contrast.  Without
this effect of strong directional light, many white areas of birds’ plumages would appear
as a solid white blob.  Slightly over-sharpening the white areas in post-process can help too.

One solution is to expose for the highlights (the whites, or the brightest colors), and hope that any clipping in the blacks will go unnoticed by viewers of the resulting image.  Research has shown that people do tend to pay more attention to the brighter parts of images than the darker parts, so this strategy does at least have some scientific support.  Note that clipping of the black regions can be corrected in Photoshop (see section 11.2) with a bit of work.  But the main advantage of exposing for the highlights is that doing so is consistent with the ETTR philosphy (Exposing To The Right—section 6.2), which has several important benefits, as we’ve already discussed.
    For warblers with more uniformly dark plumages, there may actually be some hope of exposing the blacks well, though doing so can still be very difficult.  One thing that can sometimes help is the use of strong flash.  Although feather glare is something that should normally be avoided whenever possible, for a bird with lots of black plumage, a bit of feather glare in black regions can actually enhance the perception of detail in those regions.  This is illustrated by the American redstart shown below.

Fig. 8.9.20: Extracting detail from black parts of a warbler’s plumage can be
just as challenging as for the white parts.  Strong flash can help by inducing
feather glare; though glare is something that should normally be avoided, in
black regions it can help to bring out details that would otherwise be impossible
to capture.  For the black regions that still show no detail, artificial detail can be
added in Photoshop (not shown here—see section 11.2).

In this case, though much of the head still lacks detail, the back and chest show detail in areas that without flash would very likely show up as pure black blobs in the resulting image.  Remember what glare is: it’s too many photons striking a surface for that surface to effectively absorb light of the
wrong color.  For black surfaces, photons of all colors are normally absorbed, so in an ideal setting a black surface would have no discernible detail whatsoever.  Through the use of feather glare, we can force the black surfaces to reveal some of their detail.  This in fact happens naturally in the real world when a black subject is seen in extremely bright sunlight.  So the use of flash in this way need not be seen as being terribly perverse.
    Though I’ve advocated the use of flash
power and ISO for adjusting exposure parameters when shooting warblers, the use of higher ISO values should still be avoided, as explained in section 2.5.  Though noise resulting from higher ISO settings can be reduced in Photoshop during post-processing (section 11.1), it’s worth keeping in mind that high ISO settings can also result in loss of subtle color gradations.  The safe range of ISO settings is different for every camera model.  For my Canon EOS 1D Mark III, I don’t hesitate to use ISO values between 100 and 1600, though I prefer not to exceed 800, or better yet 400.  Just remember that using higher ISO values results in the collection of fewer photons (than if you achieved the same brightness via aperture or shutter speed), which can mean poorer image quality.  (These issues are discussed in greater detail in section 2.5).
    When shooting any bird in the field, there is always the possibility that the bird will move from a sunlit perch to a shady spot, or vice versa.  For this reason, I keep two exposure
profiles in my mind at all times when working a bird: the sunny profile and the shady profile.  The sunny profile is simply the set of exposure settings to use when the bird is out in the open, illuminated by sunlight.  The shady profile is for use when the bird moves into the shade.  In practice, this typically translates to two ISO settings that I have to keep track of when working the bird.  For example, the warbler shown below, when out in the sunlight, exposed well at ISO 200 on my camera, while an ISO setting of 500 was better whenever it moved into the shade.  So all I needed to do when working this bird was to keep track of which ISO setting I was currently using (200 or 500), and switch to the other setting whenever the bird moved from the sun to the shade (or vice versa).  When the bird was half-shaded, as shown below, neither setting worked ideally, and in these cases even the best compromise can be unacceptable.  I generally don’t take any shots of the bird when it’s lit by dappled sunlight, knowing that my camera simply doesn’t have the dynamic range to properly capture both highlights and shadows on the bird.

Fig. 8.9.21: Properly exposing a bird that is partly in the sun and partly in shadow
can be an exercise in frustration.  I usually don’t bother even taking such shots in the
field, because with today’s cameras it’s often not possible to retain maximum detail in
both the bright areas and the dark areas with a single exposure.

    Now let’s concentrate on the effective use of autofocus when shooting active warblers.  This is one of the most challenging aspects of warbler photography, as has already been alluded to in our discussion of depth-of-field.  There are a number of other important aspects besides depth of field, which we’ll consider in turn.
    First, I recommend using single-shot AF rather than servo (continuous AF), despite the fact that some warblers seem to be in constant motion.  The problem is that the birds often pass behind a leaf or vine, which will confuse the autofocus system on many cameras.  Instead, I recommend tracking the bird by following it in the viewfinder while keeping your finger on the shutter release, without pressing it (not even halfway) until you’re ready to take a photo.  When you’re ready to take a shot, press the shutter release fully, so that the autofocus is engaged and the shot is immediately taken as soon as focus is achieved.  Then fully disengage your finger from the button and wait for the bird to either change its posture, turn its head, or move to a new perch.  When it does so, repeat the process by
pushing through—i.e., pressing the shutter release fully to both engage the AF and then immediately snap the photo when focus is achieved. 

Fig. 8.9.22: Since warblers tend to be fidgety, and because it’s difficult to get them in
an ideal pose, it’s useful to take a shot of the bird every time it changes its perch, its
body attitude, or the angle of its head.  Don’t even think about whether the pose looks
good before pressing the button; you can sort through the images later on your computer
and pick out just the good ones.  That way you’ll be able to spend more time (later)
comparing poses and thinking carefully about which one you like most.  There simply isn’t
enough time in the field to make these decisions when shooting an active warbler.

    This strategy has served me well, for several reasons.  First, whenever the bird changes its pose, it is a good idea to snap a shot quickly to capture that pose, before the bird moves again.  As we’ll discuss more fully below, capturing warblers in interesting poses is a real challenge, and the technique outlined above can be useful to the extent that it allows you to capture the bird in many different poses.  Of course, you’ll have to spend potentially many hours later sifting through all the thousands of images you will have taken, to pull out the best poses of each bird.  In my opinion, this is better than having too few images of the bird, with none of them showing the bird in an aesthetic pose.  The use of two-fer shooting—i.e., engaging high-speed drive mode and shooting two frames every time you press the shutter release—is another option that might be useful to you, especially for a bird that is foraging so frantically that it never actually stays still for even a fraction of a second.   For these birds, it can also be useful, when tracking the bird in the viewfinder without the AF engaged, to lead the bird a bit, by keeping the AF sensor positioned just barely ahead of the bird.  This strategy is tricky, however, so it should be explored with caution.  Note in passing that you’ll generally want to use only a single AF point when shooting warblers; I always use the center point, and turn off any point-expansion features in my camera.
    One thing that many photographers seem to be oblivious to is the fact that the autofocus module in their camera can get confused by objects that aren’t even visible in the viewfinder.  If you recall section 2.6, the AF sensors in your camera can sometimes
see parts of the scene that you can’t, because out-of-focus objects can still leave an imprint on the phase profile registered by the AF sensor (recall that the AF point itself effectively imposes its own aperture for the AF system, which can increase the depth-of-field as seen by the focusing system, relative to what you see through the viewfinder).  A very common case is when there is a thin twig passing in front of the bird, which is almost invisible through the viewfinder because it’s so out of focus, but which the AF sensor sees.  The AF system then racks the lens in and out in an apparent attempt to decide which object to focus on: the bird or the twig.  Remember that cameras know nothing about birds, so to the camera, the twig is just as valid a subject as the bird.  What you can do in these situations is to be cognizant of any discoloration you see in front of the bird, which may indicate an out of focus twig or leaf that is confusing the AF system.  In these cases I typically wait for the bird to move to a different perch.  Although it might be feasible to disable autofocus and take the shot after focusing manually, the blur induced by the occluding object typically results in a less-than-ideal image anyway.

Fig. 8.9.23: Keep in mind that out-of-focus branches and leaves can
confuse the autofocus system in your camera.  Even if you can’t see an
obstruction through the viewfinder, the AF system might see it and get
confused by it.  Also, OOF obstructions can decrease sharpness of
occluded regions in the image, even if the object itself is not discernible.

    Another thing you should do periodically is to check the AF micro-adjustment setting on your camera (if you have one) on actual birds in the field.  In section 3.11 we showed how to set the AF microadjust using a focus chart in your home.  I now set my microadjust exclusively in the field, using birds as my test subjects.  Since your goal is to get the bird in focus—most especially the bird’s eye—a good way to set microadjust is to find a cooperative bird (i.e., a relatively stationary one) and to tweak the AF microadjust setting over several consecutive shots until the eye is maximally in focus.  Since different birds are of different sizes, I find that different microadjust settings can be useful when shooting warblers as opposed to shooting hawks.  For hawks, I often end up focusing on the bird’s shoulder, whereas I want the bird’s eye to be maximally in focus, and the microadjust can be used to account for the shoulder-to-eye distance on this subject.  For warblers, the shoulder-to-eye distance is far less useful, so I set the microadjust setting accordingly when I’m in warbler mode.
    Note that as you assess the sharpness of your images in the field (by looking at the images on the camera’s rear LCD), you’ll undoubtedly review a number of images that, for one reason or another, are clearly useless and which you’d like to delete.  Deleting images from your memory card in the field can be a distraction when there’s more action to be captured, though during lulls in the activity there’s probably no great loss in spending a few minutes deleting photos that are clearly useless.  When pursuing warblers, many photographers find that their
keeper rate tends to be quite low, so that the number of useless images captured in the field can be quite large.  I personally opt to simply keep excessive amounts of memory with me in the field and to resist the urge to delete images until I get home—and even then I sometimes don’t even bother deleting bad images.  As flash card and hard drive capacities increase and/or prices drop, this strategy seems less wasteful, and has the advantage of saving a potentially more valuable resource: my time.
    As was mentioned earlier, it can be useful when shooting active warblers to take a new photo each time the bird moves.  This not only helps to capture a more representative sample of the bird’s poses, but also helps to battle the problem of motion blur, because the more photos you take of the bird, the greater the chance that you’ll happen to snap a shot when the bird was perfectly still.  It can also be a good strategy, when the bird moves behind a branch or tree trunk, to wait for the bird to emerge, rather than walking around the tree to try to get a clear angle.  For highly active birds, it can sometimes take less time for the bird to come back out in the open than for you to move around and find a clear shot while the bird is behind a branch—especially when shooting with a tripod-mounted rig.  This isn’t always the case, but as a general strategy it can be useful.

Fig. 8.9.24: Focusing on a warbler in dense foliage is very tricky.  If the bird
is close enough and the AF sensors on your camera are small enough, you may
be able to point the active AF sensor point at the bird and make the camera
focus on the bird, but often it’ll instead choose to focus on a leaf or twig
that’s close to where the AF sensor is pointing.  For this photo I moved the AF
sensor point slightly off the bird in the northwest direction, in hopes of forcing
the camera to focus on the bird’s head rather than the foreground foliage.  I
could easily tell that it hadn’t focused on the background foliage in this case.

    Leaves can be a special problem for focusing.  In many cases the bird will be partially exposed while the rest of the bird remains behind foliage.  For some cameras, at some focal lengths and effective magnifications, you may still be able to get a reliable focus via AF, while for other cameras or shooting situations you’ll find that the AF system wants to focus on a leaf or twig just in front of the bird.  It’s often not obvious, when viewed through the viewfinder of the camera, whether the AF system has chosen to focus on the bird or on an intruding twig.  Keep in mind that the AF sensor indicators that you can see in your viewfinder (the small red or black squares that denote AF points) may be larger or smaller than the actual AF sensors in your camera, so just because the red square doesn’t seem to overlap any intruding objects doesn’t mean that the AF sensor represented by that square doesn’t do so.  With experience you should develop a feeling for how your camera behaves when trying to focus on precise spots in the scene, and will then be able to make more informed decisions when the scene does include intruding elements (as in the scene depicted in the figure above).
    Remember that leaves and twigs in front of the bird, while possibly rendered almost completely out of focus, still occlude any light that your flash may be emitting.  This can result in unsightly shadows on your subject.  These problems should become apparent quickly as you check your images on the camera’s LCD in the field.  As a general rule, I check the LCD at least once whenever I start working a new subject, and then periodically while shooting the same subject.  I’ll typically zoom in all the way to 100% to check for critical sharpness (lack of sharpness can indicate motion blur, an out-of-focus occluding element such as a leaf or twig, or possibly some equipment issue such as dirt on the drop-in filter or a systematic focusing error that might be correctible via AF microadjust).  Note that when leaves begin to occlude too much of the bird it’s advisable to track the bird using manual focus instead of AF.  This is, unfortunately, difficult with warblers, due to their size.  For that reason, when a warbler is at all occluded by foliage I usually cease shooting until the bird comes out fully into the open.

Fig. 8.9.25: Capturing a warbler in a pleasing pose is a simple matter of patience.
I followed this particular individual around for a full eight hours as it foraged on
its nesting territory.  Of the many thousands of photos I took that day, probably
only 1% featured both a decent pose and an acceptable background.  (I’ll also admit
that at the end of the day the bird was still going strong, but I was dead tired.  Never
before had I been thoroughly whupped by a tiny, three-inch bird!)

    Let’s now change gears once more, and consider the issue of subject pose, specifically as it applies to warblers and other small songbirds.  As with many other aspects of bird photography, the ideal pose for a particular bird in a particular setting can be highly dependent on personal preference.  Nevertheless, there are a number of very basic considerations that apply fairly widely when shooting birds.  For warblers, the constraints become more restrictive, since these tiny birds tend to have shorter extremities than, say, herons and egrets with their long necks, long legs, and angular heads.  Warblers tend to be mostly oval-shaped, and there’s simply less potential for birds with such a shape to assume novel poses.
    Remember that the camera’s imaging sensor
and any images captured by itare strictly two-dimensional.  Profile shots thus tend to work well with many subjects, since they align the animal’s salient facial features for maximal contrast against the background, while also maximizing the potential area that can be kept in focus.  This does not rule out any value for non-profile shots, however.  Indeed, I personally prefer shots in which the bird’s head is tilted somewhat shy of a perfect 90-degree profile (i.e., is not perfectly parallel to the imaging plane).  These oblique poses often capture enough of the bird’s profile to give the overall impression of a side shot, while in some cases giving a better view of facial features and at the same time avoiding the impression of a cliché profile shot.
    In the case of birds there’s also the issue of field markings.  This isn’t just relevant for viewers who happen to be avid birders: the field markings of a species are those visual characteristics which set the bird off from its relatives, and are therefore often very striking in appearance.  Capturing a bird’s field markings with great effect can sometimes offset the otherwise detrimental effects of an otherwise suboptimal pose.  The kinglet shown below is a prime example.  Poses in which the bird is facing almost directly into the camera tend not to be favored by many viewers (though there are certainly exceptions).  In this case, however, such a pose has resulted in the bird’s field markings being strongly revealed, while also presenting both eyes to the viewer.  The foreshortening of the beak—a common shortcoming of frontal poses—is somehow less offensive in this case, possibly because the bird’s actual beak is short to begin with, or possibly because the angle of the head produces a strong facial impression that renders the beak less important.

Fig. 8.9.26: Capturing all of the prominent field markings of the bird can
be exceedingly difficult with many warblers.  Though I pursued this species
for several winters, this was the first shot of a Golden-crowned Kinglet
(Regulus calendula) that showed the bright red skull cap.  Though I avoid
frontal shots, due to foreshortening of the beak, enough of the field markings
were showing that I simply could not delete this image.

   The above image also illustrates the acrobatic nature of warblers.  Whereas human portraiture is overwhelmingly concerned with vertical postures, warbler bodies can align at any angle in an image and still look natural.  It’s for this very reason that shooting warblers overhead is not always a hopeless endeavor.  For many birds, shooting from below the bird will in most cases result in a belly shot, which most bird photographers avoid, but for active warblers you can literally obtain any pose from the bird even when shooting straight up, due to their acrobatic nature.  Note that when shooting up you’ll often have sky as a background, and in these cases manual exposure is a must.  If you try to shooting in any of the autoexposure modes in these types of situations, the rapid changes in background brightness as you change viewing angles will likely causes huge swings in subject exposure, which is usually undesirable.  See sections 6.3 and 6.4 for suggestions on operating the camera in full manual mode.
    One particular type of pose which is generally very popular for warblers is the singing pose.  An image depicting a warbler in full song can be a truly inspiring thing.  The main difficulties are getting the bird at the right angle, and getting the shot when the beak is open.  The latter problem can be solved by simply taking repeated shots during the song bout and hoping at least one captures the bird with the beak wide open.  In terms of the angle, I just try to make sure the bird isn’t facing too directly at the camera.

Fig. 8.9.27: Photos of warblers engaged in inspired bouts of singing are
to be treasured, whenever you can get them.  To improve my chances of actually
capturing this bird with its beak open, I took many shots in rapid succession (though
not in high-speed drive mode, since that mode makes effective use of flash difficult).
I did not move into position to place the bird at the desired angle, since that’s usually
hopeless for restless birds like warblers.  I instead waited for the bird to assume the
angle that I wanted.  I also took many shots at suboptimal angles, in case the angle
never got better.  Fortunately, the angle did get better, and I was able to simply
delete all those lower-quality photos taken during the bird’s operatic episode.

     Much of the foregoing assumes that you’ve solved the problem of getting close to your subjects—either by employing astronomical focal lengths or by traveling to a warbler hotspot (such as a migrant trap).  Keep in mind that if you’re having trouble getting close enough to forest-dwelling warblers to get well-lit, detailed shots, there are species of warblers that inhabit lower, more open types of habitats.  In the eastern US, for example, many field habitats attract Prairie Warblers, Common Yellowthroats, and Yellow-breasted Chats.  Marsh-dwelling birds such as the Prothonotary Warbler also tend to stay much lower and are therefore more accessible than species that stay high in the trees like the Yellow-throated Warbler.  Yet another option is to pursue birds inhabiting the same niche as, say, the Seiurus waterthrushes, which spend much of their time foraging down at the edge of the water along rivers and creeks.

Fig. 8.9.28: Not all warblers are forest-dwellers.  If shooting warblers in forest settings
has frustrated you, consider pursuing a species that instead frequents open areas, such as
this Yellow-breasted Chat (Icteria virens), or my personal favorite, the Prairie Warbler
(Dendroica discolor).  Field-dwelling warblers tend not only to present better angles, but
are also often better lit by natural sunlight.

    Finally, let’s very briefly preview some of the post-processing issues that we’ll get to in chapters 10 through 13, specifically as they relate to warbler photography.  First, let’s revisit the issue of backgrounds.  Because warblers can be so difficult to photograph, just getting a sharp, well-exposed image of the bird itself can be a major accomplishment.  If the background isn’t ideal, you needn’t throw away an image that may be your only decent one.  As we’ll see in section 13.1, it’s possible, with some effort, to completely replace the background of a photo with the background from another image.  Though this technique can be applied to any bird photo, I’ve found more uses of this technique for warbler photos than for other types of birds.  For this reason, it’s a good idea, when shooting warblers, to take a few out-of-focus shots of the forest where you’re shooting, in case you need to use any of these to merge into a warbler shot in which the bird looks superb but the background is terrible.  Merging in a background image taken in the same location is sometimes safer than merging in a background image taken elsewhere, because the lighting and color composition may be more consistent.

Fig. 8.9.29: If you don’t like how the background looks in an image, you can replace
it in Photoshop.  This takes some work, but for warbler photography the ability to do so
is often a godsend.  It’s hard enough just getting the bird perfectly in focus, with no motion
blur and well exposed.  Also requiring the image to have a perfect background can get
ridiculous.  If you’re independently wealthy and can spend all day shooting warblers, then getting
everything perfect—including the background—may be feasible.  For the rest of us, replacing
the background in Photoshop is often the best we can do.  It’s certainly better than nothing.

    Another thing we’ll be addressing in section 12.6 is how to make the bird stand out more from the background, in those cases where the bird blends in more than you’d like.  Though we’ll be considering a number of techniques for doing this, one that seems to work well for colorful warblers is to render them brighter than the background, so that they almost seem to glow with a light of their own.  The Cape May Warbler shown below illustrates this technique.  Because this species (like many warblers) is so very colorful, the elevated brightness and saturation can work well to give the bird a special prominence in the scene that, for some viewers, won’t look too unnatural.  The technique requres care, however, because it’s easy to go too far and produce an image that simply looks too unnatural.  Though I personally advocate processing your images so as to please your own aesthetic instincts without worrying too much about what other people think (especially other photographers), tastes do mature over time, and you may find later that images you thought looked great when you originally processed them now look artificial to you—i.e., over-saturated, over-sharpened, etc.  For that reason, it may be a good idea to err on the side of being overly conservative whenever applying post-processing effects.

Fig. 8.9.30: Photoshop can be extremely useful in making the bird stand out
from its background.  Since warblers tend to be very colorful, doing so via
saturation and brightness is often a good approach.  The mechanics of actually
performing these augmentations in Photoshop are discussed in detail in Part III
of this book.

    Improving the apparent sharpness of warbler photos in post-process is a special challenge.  On the one hand, there’s a tendency to want to sharpen them too much, because it’s often difficult to see enough detail on these small birds.  On the other hand, their feather patterns often create moire effects, which artificial sharpening only exacerbates.  The Prothonotary Warbler shown below illustrates both of these issues.  This bird is indeed over-sharpened.  Some of the over-sharpening, particularly in the bright areas, may arguably enhance those parts of the image by exaggerating fine feather details that otherwise would be lost.  Note that in this image there is an additional factor at work: the use of flash, which has exaggerated fine details via the micro-contrast phenomenon (section 4.3).  Though micro-contrast can be very useful for increasing the apparent sharpness of the bird, it can make sharpening in post-process trickier.  In this particular photo, you can also see some prominent glare in the blue feathers of the wing; some over-sharpening is also apparent in this region.

Fig. 8.9.31: Sharpening warblers in post-process is a special challenge.  Their
small size makes it difficult to capture enough detail, and though sharpening in
post-process can help to exaggerate what detail you are able to capture in the field,
doing so without inducing unpleasant artifacts can be very difficult.  In this case,
over-sharpening had been applied to exaggerate details in the yellow regions of the
bird’s plumage, though moire effects in the wing coverts (as well as some feather
glare) result, to the slight detriment of the image.  Sharpening techniques are
discussed in detail in section 11.6.

    The above image also illustrates the problem of moire in feather patterns.  For warblers, the wing coverts and back are typically the problem areas in this regard; you can see in this image the strong hashing or gridlike pattern in the coverts, which is just starting to exhibit digital interference patterns.  This moire pattern is a natural feature of this bird’s plumage, but it still needs to be treated carefully in post-process to avoid making it stand out more than is desirable.  More generally, individual species often have their own special considerations that should be taken into account during post-processing.  For example, I find that sharpening Northern Parulas and Palm Warblers is more difficult than sharpening other warbler species, due to the species-specific structure of their feathers.  These are simply some things to keep in mind when post-processing warbler images.
    Techniques for post-processing bird images will be discussed in great detail in Part III of this book.