[Pat]

I want to add a medium telephoto lens for candid street photos at a distance of 35-50ft, I am keen on the 200mm f/2.8, however have to keep in mind my camera a 400D - would it be too long? cant see myself shooting birds etc or football, soccer. Prefer a fast prime, any advice? :/

[matthew]

Hi Pat;

Personally, I would suspect that a 320mm EFL would be too long for street/candid photography, but I have found a few people who love a particular 300mm EFL prime for it, so you may be on the right track.

If I was using a Canon, I'd probably be more tempted by the 135 f/2. In this case I think the shorter lens may be a little more versatile, but it all comes down to shooting styles and the subject that you like. They're both very well regarded, so it's hard to go wrong.

[shuttertalk]

Hey Pat, interesting question... Phil Greenspun has a great article on photo.net
http://www.photo.net/photo/tutorial/lens.html

There's even a calculator halfway down the page, and you enter the distance to subject, and how high the subject is that you want to fill the frame. So say for example a 6 foot object (average person) at 50 ft, yields:

On a full-frame Canon digital SLR or a 35mm film camera, you will need a 311mm lens. With an APS-C digital sensor, such as found on a Canon Digital Rebel or Nikon D-series camera, you will need a 186mm lens.

Here are the raw numbers:

* distance to your subject: 50 feet (600 inches)
* long dimension of your subject: 6 feet (72 inches)
* magnification: 0.0208333333333
* lens size required: 12.2448979592 inches (311 mm)

Assumptions: You are using a standard 35mm frame (24x36mm) whose long dimension is about 1.5 inches. You are holding the camera in portrait mode so that your subject is filling the long side of the frame. You are supposed to measure subject distance from the optical midpoint of the lens, which for a normal lens is roughly at the physical midpoint.

Hope that helps...

[Pat]

Thanks for that advice guys - asked my tutor at photography school last night and his advice was to work on the assumption that you could, with a 400D, shoot at 30 metres for a 300mm lens, 40 metres for a 400mm and therefore 20 metres for a 200mm (this is simpler for my brain to understand ) - am keen on the Canon 200mm f/2.8 so hope to have it in the next few weeks. Will let you know how it works out :/

[shuttertalk]

Hey that's a pretty good rule of thumb, Pat... thanks!

[Wedding Shooter]

Pat - the 200 2.8 is a wonderful lens. Enjoy.