• John Gerlach

Long Lenses for Wildlife Photography

Updated: Feb 26

All photos in this article were shot with a Canon 90D and one of two lenses - either a Canon 100-400mm or a Canon 600mm F/4 III.

My Canon 90D camera with its 1.6x crop factor due to the small sensor size nicely caught this vermillion flycatcher with a Canon 100-400mm lens set to 400mm hand-held. Since I seldom shoot hand-held, I favored a higher shutter speed of 1/500 second and set the image stabilization to Mode 1 so all directions were stabilized for camera movement. Note that image stabilization does not arrest subject motion. For that you need more shutter speed, real smooth panning, or flash.

Long Lenses for Wildlife Photography

I began photographing wildlife in 1972 with a Canon 300mm f/4 lens. By using photo blinds to hide from wildlife or photographing in places where wildlife is habituated to humans, I still did fine in that era. A bigger problem was the slow film I had to use – Kodachrome 64. Imagine using ISO 64 for wildlife photography! Now all of us routinely use much higher ISOs with our digital cameras to shoot beautiful images.

Having earned my college degree in wildlife biology, I naturally pursued wildlife photography. By the early eighties, I used a Canon 500mm f/4.5 lens to produce pleasing wildlife images that I regularly sold to my clients who included Ranger Rick, National Wildlife, Audubon, National Geographic publications, and many others. The 500mm worked well for me and was a huge improvement over the 300mm. I used several 500mm lens versions over the decades. Another long lens I could have bought was the Canon 600mm, but it was huge in bulk, weight, and price. Since I pursued macro and landscape photography too, I did not purchase it, though, I would have if I only photographed wildlife.

The reach of the Canon 90D camera on the Canon 600mm f/4 III lens is 960mm. This let me capture a nice size image of the snowy egret at a greater distance such that it tolerated and did not fly from my approach. Exposure is set manually to produce the first blinkies in the whitest feathers.

Wildlife photographers enjoy great benefits by having the reach of a long lens – the longer the better. I did try using 1.4x and 2x teleconverters on my Canon 500mm lens in the early days, but the quality (image sharpness) did not meet my standards, so I used the early teleconverters very little for most of my career.

By 2010, I wanted far more focal length reach, so I bought the Canon 800mm f/5.6 lens. That lens opened an entirely new world to wildlife photography. Now I could easily capture most wildlife large in the image if I wanted to. I have never been a big fan of the “dot bird” approach where wildlife is photographed from a great distance, so they are tiny in the image, and then blown up tremendously when the digital image is processed. Indeed, I remember one Kenya client showing me a bird he just photographed in the safari vehicle with me next to him that I never saw. Of course, the bird’s image was enlarged a lot. When I asked him to show me the bird’s image without any extra magnification on the camera’s LCD, he did, and I could not find the bird in the image. Then he told me the red focus square was covering up the bird. Now that is far too small of a subject in the image for me.

Bighorn sheep are plentiful in the wildlife refuge near Jackson, WY, and especially so around and on Miller Butte. Here are two I photographed in mid-December of 2019. Once again I used a 600mm lens with a Canon 90D camera.

Since the 800mm lens is a f/5.6 lens, I never tried using a teleconverter with it as that slows the lens down too much (a 1.4x teleconverter slows the lens to f/8) and greatly reduces the effectiveness of the autofocus system. I was happy with that 800mm lens for a decade. It produced excellent results with good color and super sharpness.

Lens choices continued to evolve, and, in the spring of 2019, I bought the new Canon 600mm f/4 III lens. It cost a whopping $13,000 – three times more than the first new Chevy pickup I bought in the seventies! Why would I buy a 600mm lens when I already had an 800mm lens? The lens focuses down to 13.78 feet while the 800mm’s minimum focus distance is 19.7 feet. Thirteen feet as a minimum focus distance is helpful for photographing small birds and mammals. With the 800mm, I found it annoying to be able to approach a palm warbler in Florida closer than twenty feet but could not focus the bird unless I backed up to 19.7 feet and then it was tiny in the image. I could add an extension tube to focus the 800mm closer, but that cost you light. Being able to focus closer is frequently beneficial for successful wildlife photos unless you only photograph big subjects like deer, elk, and moose. In summary, the problem with the 800mm is the 19.7 minimum focus distance for small subjects forces you to keep the subject much smaller in the image than desired.

Moose are abundant during December in the sagebrush flats north of Kelly, WY. We saw as many as a dozen in one day, and also saw several along the roads north of the airport. It is a real treat to photograph moose and bighorn sheep in Grand Tetons National Park during December. It should be on your "bucket list." I do plan to offer small photo workshops for five eager photographers based in Jackson during December and the peak fall color week of late September. Just today I applied for my CUA to operate in the park.

Of course, the 600mm lens does not provide the reach of my 800mm lens, but teleconverters have come a long way. By pairing the Canon 600mm f/4 III lens with the latest Canon 1.4x teleconverter, the photos are truly sharp – even for this teleconverter skeptic. And when you pair the 1.4x with the 600mm lens, you now have an 840mm f/5.6 lens and that is more reach than the 800mm. And all wildlife photographers soon discover more lens reach is enormously useful in wildlife photography!

Even the little guys like this muskrat are fun to photograph at Flat Creek near Jackson. This muskrat paid no attention to me as I filled the frame with it using a 600mm lens and the Canon 90D.

Over the decades, I only used full-frame sensor cameras for wildlife photos. I did this because I wanted the best image quality I could get. The more pixels on the subject, the better. Plus, full-frame sensors tend to be better when high ISOs must be used, and high ISOs are frequently necessary in wildlife photography. Another reason I used the full-frame sensor cameras – currently the Canon 5D Mark IV and 1DX Mark II – is sometimes wildlife subjects approach me too closely forcing me to compositionally cut off parts of the subject. Naturally that happens more often with the small-sensor cameras.

A zoom lens is the key for photographing wildlife from a safari vehicle. Since you can't change shooting distance easily, to accommodate wildlife sizes, a zoom lens is a must.

A prime lens is a fixed focal-length lens such as a 500mm, 600mm, and so on. These are great lenses to use, but not when you can’t adjust your shooting distance. That problem happens most often when you are hiding in a blind or photographing from a vehicle on an African safari. I learned years ago while photographing sage grouse, sharp-tailed grouse, and prairie chickens from a blind when they dance on their lek, a prime lens is a problem as often the subject is too far away or too close for the chosen focal length. In such situations a zoom lens is king since the focal length is easily changed to fit the circumstances. Two of my lenses that handle the situation where I must be stationary, and the subject moves, are the Canon 100-400mm and the Canon 200-400mm. But neither lens is especially long in focal length. With a Canon 1.6x crop factor camera, the 100-400mm produces the field of view of a 160-640mm lens and the 200-400 has the field of view of a 320-640mm lens. These lenses are now super with the small-sensor camera for blind and safari photography where you must be able to change the focal-length quickly.

A canvasback on a pond during January in Freestone Park near Phoenix, AZ The 600mm paired with the Canon 90D gave me an effective focal length of 960mm so I could photograph them at quite a distance. I prefer the low angle to the duck. If the duck is photographed with a shorter lens from a closer distance, the angle is not as desirable. These ducks do not fear people and will approach to a foot or two if you have seeds for them.

I once thought if I must photograph an animal smaller than I prefer with a full-size sensor camera, I can always crop the image later in the digital darkroom. That is true but filling the image more by using a crop factor camera (like the Canon 7D Mark II or new Canon 90D) that has a 1.6x crop factor seems to produce the better image with greater resolution. Small sensor cameras have plenty of pixels now, and they are typically packed in close together. This means you have more pixels on the subject with the small-sensor camera than cropping the image a lot with the full-size sensor camera. Of course, tightly packed photosites on the sensor tend to be noisier at higher ISOs, so don’t overdo the ISO with small-sensor cameras.

I like the restfulness of the drake ring-necked duck on a pond at the Gilbert Water Farm. The early dawn light reflecting off a bush creates some pleasing colors in the Ranch.

I recently received a question from a client. “What camera and lens should I get for doing serious wildlife photography?” He was in his seventies and retired. That means weight, bulk, and perhaps money were all factors in his decision. Normally I would suggest what I use, but does it still make the most sense, especially when you consider most pictures are used on the Internet?

Although the late evening light is a little harsh, I like the desert cottontail's vertical pose as it nibbles the vegetation. The reach of the Canon 90D and the 600mm lens kept me back far enough to avoid interrupting this hungry "hopper."

For the past year, my long lens choice has proven to be the best option I ever had. I use the Canon 1DX Mark II with the Canon 600mm f/4 III and often add the 1.4x teleconverter to make it an 840mm lens. It is a dynamite combination for me! But that is a lot of weight, bulk, and the price tag is about $20,000 for everything. There are plenty of quality alternatives that cost far less and aren’t nearly as heavy. Many lens makers offer zoom lenses in the 200-500mm range. These are quite useful and affordable. And with a crop-factor camera like the Canon 90D, the high-quality and far more affordable Canon 100-400mm lens when used with the 90D camera with its 1.6x crop factor has the field of view of a 160-640mm lens and that combo is at least $17,000 less expensive than my “ultimate” choice.

Using a shutter speed that is really too slow, but needing to for more depth of field to get both little bee-eaters sharp works when you shoot far more images than normal. Though, the shutter speed is too slow for sharp images most of the time, every once in awhile all the wiggles and wobbles cease for a moment and you get a sharp image anyway.

To try out the crop-factor camera, I bought the Canon 90D late in the summer of 2019 and have been using it extensively to photograph birds in Arizona and bighorn sheep and moose in the Tetons. As already mentioned, that camera paired with my Canon 100-400mm offers the field of view of 640mm when zoomed out to the 400mm focal length. That proved to be the perfect combination to photograph a vermillion flycatcher at a park in Phoenix, Arizona. While I nearly always use a tripod, bean bag from a vehicle, or Wimberley head attached to my floating blind, and rarely shoot handheld, I knew tripod use was far too slow to keep up with the flycatcher since it its perch every minute or two while hunting insects. Instead, I handheld the Canon 90D with the 100-400mm lens set to 400mm to get the field of view of 640mm and followed the gorgeous flycatcher around its hunting grounds. By moving s-l-o-w-l-y with the camera already up to my eye, I easily approached the small flycatcher to excellent photo range of about eight feet. By favoring a higher shutter speed of at least 1/500 second, and with image stabilization on and set to Mode 1 to make the system stabilized in all directions, I got plenty of sharp images. Still, when using the best handheld techniques, I always shoot more images than normal because sometimes the wiggles from handholding stop momentarily to produce incredibly sharp results. My strategy worked perfectly as I made many sharp images.

A frosty morning offers some unusual looks at a hungry bighorn sheep near Jackson, WY.

I should mention I did test the Canon 7D for wildlife photography quite a few years ago. The sharpness produced by the small-sensor camera did not meet my standards, so I reverted to the cameras with the full-size sensors. Looking back now, I realize the sharpness I was looking for and did not achieve was most likely not the fault of the small sensor in the 7D, but instead the camera and lens needed to be AF microadjusted for precise autofocus. Today, I AF Microadjust all lenses and cameras where I use autofocus by looking through the viewfinder, and not the live view method. Even my new Canon 90D was backfocusing a little, so I needed about a -5 AF correction to make the lens focus precisely on the subject – not a little past the subject. It is a small correction, but significant to me as my images are noticeably sharper!

Due to the working distance provided by the 1.6x crop factor Canon 90D and the already long Canon 600mm f/4 III, the effective 960mm lens (in terms of angle of view) kept me back far enough where this green heron paid no attention to me at all.

While in Phoenix, I was visiting the famous duck ponds such as Freestone Park where wild ducks winter and became habituated to people by January. I could have used my full-frame sensor cameras but wanted to see how shooting with the 90D (1.6x crop factor) would do and if there were any benefits. From editing thousands of images shot with the 90D, I feel the images are excellent, so no worries about image-quality. The joy of using the new Canon 90D with my 600mm lens is now I have the benefit of a (600mm x 1.6x crop factor) = 960mm angle of view. Now don’t get me wrong. The crop-factor camera does not make the 600mm a 960mm lens. It remains a 600mm lens, but the field of view is 960mm. That means you get images where the subject is large in the image from a much greater distance. A canvasback further out in the pond means your shooting angle is more favorable as the view is closer to the duck’s eye-level rather than use a shorter lens and photograph ducks closer to you where the viewpoint is more aerial and you shoot down at the duck. Plus, often when the ducks are close to shore on the Phoenix ponds, they are most densely packed together making it difficult to isolate a single bird. When further out in the pond, they preen, splash, assume cute natural poses, and that all adds up to more interesting images. When close to shore, the ducks are hoping to be fed by park visitors and watch all who come close and you don’t get much opportunity for behavior images.

Once again the reach of the Canon 90D and the 600mm let this drake American wigeon behave naturally - providing me with many sleepy poses and preening poses too.

My Conclusion:

I will be using crop-sensor cameras more often for wildlife photography. Paring a small-sensor camera with a zoom lens that reaches at least 400mm is a productive combination that is far less costly than a prime 600mm or 800mm lens. Indeed, when I begin using my floating blind for wildlife photography this spring, I will be using a crop sensor camera. I do well in my floating blind when using the Canon 600mm with the 1.4x teleconverter to make it an 840mm lens on wild water birds, but some birds are a little shy of the floating blind and even 840mm isn’t quite enough reach. With the Canon 90D on the 600mm lens, that is like having a 960mm lens! And should I add the 1.4x teleconverter too, then I have the angle of view of a 1344mm lens!!!! (600mm x 1.4x x 1.6 crop factor camera = 1344) Now, that is impressive!!!!! I look forward to using the new 1344mm combo, reviewing the results, and I will report my findings when known on my web site.

I wonder if I could do this now. Green herons have excellent balance!



This Sage Grouse was busy eating sage late one afternoon near Grand Teton National Park. Shooting out the car window with my Canon 90D and 100-400mm lens, I easily photographed it when it appeared large in the viewfinder. The crop factor of the 90D, 1.6x, gave me the field off view of a 640mm lens. That made me happy to see the bird easily and it helps me put the AF point right on the bird's face.



Once again the Canon 90D with the 100-400mm lens worked well to let me compose this frosty bison in Grand Teton National Park in a pleasing fashion to me. A single AF point was right on the bison's nose when I took the shot with a tripod-mounted camera.

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