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What size lens is recommended for flying bird photography?

I am having trouble deciding which lens I should buy my wife to go with her new Canon 7D. She uses it mainly for birds, including both at a distance and in flight.

My basic logic is that if two lenses provided by a manufacturer for a similar purpose is more expensive than another, then the the more expensive one is the better one. Could you please advise me if this simplistic thought is correct?

If it is a little or a lot more complicated, could you please advise me of your thoughts, having regards to my limited photographic knowledge.


Owning the 100-400mm lens myself, I can say it is a superb lens to photograph birds with. It has some excellent IS, and supports a fairly wide range of focal lengths that will help you capture birds at a variety of distances and in a variety of scenes/poses. The push-pull zoom is handy as well, as it makes it easier (with practice) to zoom and focus simultaneously, something I find hard to do regardless of skill when you have two rings for those functions. The image stabilization of the 100-400 is dual-mode (full and panning), so it can help when shooting hand-held shots of perching birds, as well as gymbal or monopod supported panning shots of birds in flight.

In contrast with the 400mm f/5.6 L lens, the 100-400 has several advantages, while the 400mm has only a few. First off, the 400mm is a prime lens. While this will give it the edge in terms of image quality, and will make it smaller and lighter for hand-held operation, it limits your options. Second, the 400mm f/5.6 L lens has no IS. If your only interest is to birds in flight, its an excellent lens, however the lack of IS is definitely limiting, and will make it difficult to shoot perching birds at a distance. In most cases, the 100-400mm lens is a far more versatile lens, with the only real detriments being its slightly greater weight and slightly softer images at 400mm.

A better comparison would be between the 100-400mm and the 500mm f/4 L IS lens. While 400mm does give you a nice wight-to-reach balance, it often tends to be just not quite enough reach to really get you frame-filling bird shots without them scaring and flying away. If you are willing to spend the money on a decent prime lens that supports hand-held operation, the 500mm or 600mm L IS lenses are much better options. On a 7D body, the 500mm gives you an effective 810mm reach, while the 600mm gives you and effective 970mm reach. The wider aperture and IS make it a lot easier to get stable hand-held shots at a distance great enough not to scare off every bird you try to photograph.

With a 7D camera body, you could even use the 500/600mm lenses with the 1.4x extender, to provide even greater reach (1135/1360mm) without losing AF capability for all 19 points! For a bird photographer the ability to extend the focal length of those two lenses, keep full AF capability, AND have IS is about as good as it gets. Sadly, the 500mm and 600mm lenses come at significant cost, and are well out of range of most photographers. As such, it makes 100-400mm still the most versatile option for a bird photographer.

  • You are right jrista the 500 and 600 are well off my budget. – Dennis Jun 15 '11 at 9:24
  • Thanks jrista, unfortunatly the 500 and the 600 are well out of my price range.Can you use the 1.4 extender with the 400 and the 100-400? – Dennis Jun 17 '11 at 8:27
  • @Dennis: You could, but you would entirely lose any AF capability, which would make most bird photography rather difficult. Extenders multiply the maximum aperture as well. Something with an f/5.6 maximum aperture would have an f/8 maximum aperture with the 1.4x extender. Part of the reason the 500 & 600 are so expensive is they have, for their focal length, VERY large maximum apertures at f/4. With the extender, they are f/5.6, which still allows AF to work on most Canon cameras. Generally speaking, using the 100-400mm on a 7D will give you more than enough reach to do bird photography. – jrista Jun 17 '11 at 17:07
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    Jrista, thanks, I have now made my mind up, the 100-400, just got to wait until I get the money together. – Dennis Jun 17 '11 at 23:11

It all comes down to what she wants to use the lens for. The zoom lens with IS will certainly allow her to use slower shutter speeds at the 400mm end than the prime, but it will also be heavier (1380g vs 1250g) and will lose image quality by being a zoom.

I can't really see the added range of the 100-400 being of use to a bird photographer, as I struggle to get close enough even with a 300mm prime (albeit on a full frame model), so it comes down to the IS factor and weight. Shooting birds in flight will usually require a fast shutter speed anyway, meaning the IS doesn't really help here either. So looking at it like that, the lighter, cheaper prime would seem to be a better option.

  • Thanks Nick, yours looks like good advice to me . The main thing my wife is looking for is image quality, together with a camera and lens that is not too heavy – Dennis Jun 14 '11 at 22:41

If IS is the only deciding factor, then sure, IS is good. That said, when comparing those two lenses I know of two other factors that are probably more important than image stabilization:

  • The 100-400 allows for a wide range of focal lengths. The 400mm prime restricts the photographer only to super-telephoto images. For birding this isn't a huge restriction, but if you hope to use the lens for anything closer to the camera, it's something to consider.

  • This point is debatable but seems to be a consensus both online and amongst the three 100-400 owners I know offline: the 100-400mm is a bit soft at either end of the zoom range. It's not horrible, but if you compare the same image taken with the 100-400 vs. the 400 prime, the prime will be noticeably sharper.

Between those two lenses, I'd go with the 400mm prime lens unless you know that your wife will want to create images of subjects that are closer to the camera.

  • Thanks Aaron, My wife has other lenses to use for images closer to the camera. Looks as if there yours and Nicks advice is the same.Sharp images , particularly of flying birds and birds at a distance is what she is after. – Dennis Jun 14 '11 at 22:29

I own the 100-400 and have used it extensively for bird and nature photography. I also own the 300 F/4 IS, which I use a lot combined with the 1.4x tele for a 400ish F5.6 lens. That's roughly comparable to the 400 F/4 (it's a bit stronger and a stop slower).

The 100-400 is a killer lens for bird photography; it's a type of photography where a lot of the time you will want to hand hold, and the IS makes a big difference in less than pristine light, which you'll run into a lot. I typically use the 300/1.4 combo when shooting off of a tripod because the prime lens is sharper, but the 100-400 is definitely sharp enough.

If I could only own one lens, it'd be the 100-400 (it's also what I bought first); turn off IS and it works fine on a tripod. The 400 would be a fine lens, but less flexible if you get in close or want to do other kind of work (like flowers or insects), but it'll be sharper, but the difference isn't as much as some lead you to believe. both are big and hefty lenses so there's no significant advantage there.

If your primary interest is birds, though, it's hard to beat the 100-400. You can see some of my work here if you want (http://bit.ly/kifm8n), and the vast majority of that is from the 100-400.

  • Thanks chuqui, Looks like you and Jrista are of the same opinion which puts the vote so far at 2 all. I have had a look at your site and certainly you have taken some magnificent photographs. My quest continues. – Dennis Jun 15 '11 at 9:28
  • for what it's worth, I've changed around my camera bag, and I'm reitring the 100-400 in favor of the 70-200 F2.8 with an added 2x teleconverter. I've been using the 300F4+1.4x combo a lot more over time, and the more I do, the more I like it, but I'm going to do some head to head competitions between the 70-200/2X and 300/1.4x to see how the sharpness and focus speed compare. (some notes on why I'm doing this here: bit.ly/taujvl and some early sharpness looks here: bit.ly/rP1vJX). I still love the 100-400, but it was time to do some upgrading. – chuqui Dec 31 '11 at 2:16
  • Hi chuqui. I got Di the 100-400 as an early Christmas present, so far the results have been great. Unfortunately her 7D has developed a fault and is in for repair. Some of her work is on Redbubble (dilouise) although the majority with the previous lenses the latest ones with the 100-400. There is an improvement in clarity at the longer distances. – Dennis Jan 2 '12 at 16:41

400mm is a pretty long lens for an APS-c body, you're going to need to be shooting around 1/800s which will require pretty good light, or high ISO to use it handheld without camera shake.

If the 3-stop stabiliser on the 100-400 lives up to it's name you ought to be able to shoot at 1/100s and thus let in 8x as much light (or to put it another way, extend shooting 'till the light level has dropped to one eighth).

I know that shooting moving targets requires a fast shutter so IS isn't that good for birding, but you said "mainly for birds" which implies the lens will be occaisonally used for other purposes (e.g. portraits, candids, still nature) that will benefit from the wider zoom and IS.

It depends on what other shorter focal length lenses you have, but I'd say £200 is well worth it for a far more versatile lens.


I have rented both of these lenses and used them for taking bird and wildlife photography. For me, the 100-400mm was better.

This is partly due to the IS which gives a significant advantage in low light, and partly due to the flexibility of being able to choose a suitable zoom.

I didn't notice the 100-400mm being softer than the prime; in some photos the prime was worse due to movement blur in the evening shots as I wasn't able to use a tripod.

If you are in a location where you can find a cheap lens rental service (or a photography club with members with these lenses) I would recommend trying them out before going for one or the other.

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