Unfortunately wildlife photography, and bird photography in particular, benefits from long, fast and sharp lenses. And those three factors combined means very very expensive lenses. Something like a cheap dslr and a 70-300mm can get fairly decent shots. But for the top notch shots you really are looking at a lenses such as a 300mm f2.8, 400mm f2.8, 500mm f4 or 600mm f4. But obviously those are often beyond peoples means. Depends on your budget and how far you want to go.
That pretty much sums it up. I manage fairly well with my Canon 40D and 50D with my 100-400 zoom lens but at today's prices that's around £1700 or more for just one body and lens. I also have a 1.4X teleconverter for times when 400mm is not enough.
Here are some examples with the 40D....
Here's an example from my 50D, 100-400 and 1.4X teleconverter. That's equivalent to a 560mm lens. First the whole image and then a 100% crop....
I'm afraid I only know the Canon system so I can't comment on alternatives but there are a few general things to note....
- The image quality available from any of today's crop body DSLRs is very good indeed. In fact, for most types of shooting you would be hard pressed to tell much difference between any of them, especially at lower ISOs. In other words, a cheap, entry level body should be capable of fine results as far as IQ is concerned.
- Where the bodies to begin to differ, as prices rise, is in features, AF performance (very important for birds in flight (BIF)), durability and ergonomics. For perched birds even modest AF performance will be perfectly OK. For birds in flight you will benefit from fast AF, possibly with additional focus points available. I don't know how well the entry level cameras compete in this regard but I seem to do reasonably well with my old 40D.
- The real differentiator for image quality will be the choice of lens. Length is very important. At the budget end of things a 70-300 range would be ideal, 55-250 at a push. Optical quality does vary between lenses and there are a fair few choices to choose from when you include the likes of Sigma and Tamron as well as the main camera manufacturers. I can't comment on any of them from personal experience but I know the Canon EF 70-300 IS lens is well thought of with respect to IQ. There is also the focusing speed and accuracy of the lens to consider. Again I can't tell you which are better than others but I imagine the Canon, with its USM focus motor will be at the head of the pack for speed and accuracy. Finally there is the question of image stabilisation. For handheld shots this can really improve your keeper rate, especially at the long end of the zoom. At 300mm without IS you would probably need a shutter speed around 1/500 or faster to avoid camera shake blurring your images. With IS you could comfortably reduce that to 1/125, if your subject was still enough.
- One last point - when choosing your first DSLR it is easy to be tempted by price as a significant factor in the decision making process. That in itself is fine but consider that you are likely to be starting on a journey that has you buying accessories, additional lenses, more accessories and more lenses. I bought my first DSLR 2.5 years ago and started with a 30D and 17-85 lens. Shortly after I added a flash, then another lens, and a grip, then four more lenses etc. etc. I'm now up to four Canon bodies, 8 lenses (3 more on order), two flash guns, two grips and a whole bunch of other stuff. The point is, when you buy your first DSLR you are buying into a
system that you will probably build upon as your interest and finances grow. With that in mind you might want to consider whether the choice of brand you make today might lead you into a dead end or having to pay more in future for things that are cheaper from other manufacturers. e.g. when you are ready for your first 500mm f/4 lens, will you be able to get one to fit your chosen camera system? Is there even the option of a 100-400 lens, or something similar, for your chosen brand, and how much does it cost?
