f 2.8???

geoffraffe

Hi, could someone explain what the numbers after the f, mean. I'm looking to buy a 70-200mm lens for my canon 400d and I'm stuck on this point.

I'm only starting out on dSLRs and I'm not sure whether I splash out on the f2.8, or go cheaper model. Does anyone have any recomendations.

thanks for your help.

ThOnda

It is something to do with relative size of the hole in the lens. The smaller number, the better, me thinks.

pixbyjohn

http://photo.net/nikon-camera-forum/00FiqH also this one http://www.uscoles.com/fstop.htm
Try this link for info you require.
Cheers

PaulieC

IMO you should probably spend some time studying this area before splashing a sizeable chunk of cash on a 70-200 f2.8...it's a lot of money to spend.

Zillah

As a rule: the smaller the F number, the larger the hole, the more light that gets in, the shorter the exposure and the more shallow the depth of field. Vice Versa.

As said, do plenty of reading on this before making any hasty purchases, so that not only will you make a good choice but you'll be better able to take advantage of whatever you do buy once you know exactly what it does.

If you plan on shooting anywhere other than outside during the day 2.8 is handy. If you intend on doing any sort of very dark stuff like gigs then 1.4 would be very useful, but quite pricey.

This of course assumes no flash.

geoffraffe

Thanks a million for your help