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Photography Question 
Ken Pang

Best Lens

I currently own a Canon 75-300 f/4-5.6 IS USM lens which has been fantastic for wildlife photography. I have found however, that it's pretty poor for any kind low light photography.

I was thinking of getting the Canon 70-200 f/2.8 lens, but for that sum of money, I thought I should get another opinion on the following points:

1) Camera Shake
Using my current lens, at 200mm, I need 1/50th of a second (IS turned on) at f/5.6 to eliminate camera shake.

Using the new lens, at 200mm, I need 1/200th of a second at f/2.8. That's not likely to happen even with ISO 1600 speed film, is it? (PS. Anyone know how to calculate the shutter speed at f/5.6 for a more meaningful comparison?)

By those numbers, am I going to be able to get any better photos?

2) Photo clarity
Since indoor photography doesn't seem to benefit, will I get better outdoor photographs? I am starting to blow some of my better photos up for friends who want them as posters, and often I can't tell if out of focus/shallow depth of field problem, or a lens clarity problem.

3) Other advantages.
Are there any other points that might have forgotten about?

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Jon Close
BetterPhoto Member Since: 5/18/2000
  Getting 1/250 shutter speed shouldn't be a problem. 1/250 and f/2.8 is the same exposure value as 1/60 at f/5.6 (-2 stops in shutter speed offset by +2 stops of aperture). Regardless, you really should get a good tripod if you're making enlargements.

"Photo clarity" will be much improved whether indoors or out with the EF 70-200 f/2.8 L USM, and also with Canon's new EF 70-200 f/4 L USM. The L zooms use several Ultra Low Dispersion elements (hence their high cost) which assure high resolution and high contrast throughout the entire zoom range. The more economically designed 75-300 f/4-5.6 gets noticably "soft" above 200mm.

Other advantages of the EF 70-200 L (both f/2.8 and f/4) are (1) the lens length (and its balance) do not change with zooming or focusing. (2) the front lens element does not rotate with zoom or focus, making it very convenient to use with a polarizer, (3) they have a tripod collar (optional on the f/4) for better balance and to relieve stress on the lens mount when using a tripod, (4) the viewfinder will be brighter with an f/2.8 lens, an aid to focusing and composition, (5) true ring-USM focus motors are faster and quieter than the 75-300's micro-motor "USM" and also allow full-time manual "touch-up" without flipping the AF/MF switch, (6) they have a focus limit switch to keep the lens from focusing through the full range of 1.5m to infinity.

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