Which telephoto lens to choose? [closed]

Question

I have a Canon EOS 50D and 3 lenses:

• Canon EF-S 18-135mm f/3.5-5.6 IS
• Tamron SP AF 90mm F/2.8 Di Macro
• Canon EF-S 10-22mm f/3.5-4.5 USM

I want a telephoto lens to take pics of small animals in nature. Something like birds, squirrels and so on at a distance. I want to be able to stand far enough not to frighten the animals and still get close-up, detailed photos of them.

I'd like to be able to stand near the tree and take pics with quality similar to this photo.

With my current lens I can do something like this, but I need a very friendly animal and be able to stand almost in front of it.

Or like this or this With my current lenses they are too far and not close-up and detailed.

So, what can I choose, if I have about $600 (but not more)?

Answer 1

Three of the four photos you link in your question were made using equipment you already own.

The first was made with a lens for which you don't have an equivalent. But the angle of view used in that first one is roughly equal to about 205mm with your 1.6X APS-C camera. That is only about twice the focal length used with the other three lenses.

The reason the fairly small bird in the first photo fills the frame, and thus shows much more detail, is because the photographer, or at least the camera, was closer to the subject. The difference in angles of view given by a telephoto lens available at your price point is only a small part of the overall equation to get from examples #2, 3, and 4 to example #1.

Better fieldcraft is the true solution.

To get the kind of detail the first image demonstrates with a shutter time of 1/640 second using a 330mm (on FF) focal length probably means it was taken from tripod, or at the very least a monopod, mounted camera. It is quite possible the camera was aimed at the perch and triggered remotely to avoid spooking the bird.

Answer 2

That first image you references was taken with a Fx lens at 330mm (Appears to be the Nikon 200-500mm. Your farthest reaching lens is your 18-135mm. (ignoring crop right now as it was shot on Fx)

To reach the effective focal length, on your crop sensor you need about 220mm. Not shooting Canon, I'd say the Canon EF 70-300mm f/4-5.6 IS II USM fits all your needs.

Effective focal length of 105-450 should be more than enough zoom, and is relatively cheap at ~$500 USD.

Answer 3

Lenses are fitted to cameras based on what is “normal” for the format size. Your camera sports an APS-C size image sensor. The imaging area of this chip measures 16mm wide by 24mm lenght. A lens is designated as “normal” if its focal length about equals the corner to corner measurement (diagonal) of the image area. In this case, the diagonal measures 30mm. If you mount a 30mm, the view delivers is said to match the human view (view of the unaided eye). Mount a 60mm and objects will image as if they were twice as close as actuality.

20mm = or shorter = wide-angle

30mm = “normal”

60mm = 2X magnification object 100 feet away images as if 50 feet distance.

120mm = 4x magnification object 100 feet away images as if 25 feet distance.

240mm = 8X magnification object 100 feet away images as if 12 ½ feet distance.

500mm = 16.6X magnification object 100 feet away images as if 6 feet distance

1000mm = 33X magnification object 100 feet away images as if 3 feet distance.