View Full Version : focal lengths, apertures, depth of field

11-20-2005, 05:43 AM
Hello Guys !

Ive got a technical question concerning focal lengths and apertures.
At the moment, I own a D50 with 50mm f1.8 lens, and Im thinking about buying the 35mm f2 or 28mm f2.8 prime too. Is it right that the depth of field, I mean the "in-focus-area", is larger with lenses with smaller focal lengths if I use the same aperture ? As an example : if I set my 50mm f1.8 to aperture 2.8 an take a photo, and then I change lenses to a, say 35mm or 28mm prime, and take the same photo (that is to say I focus on the same subject) also with f2.8...then will the in-focus-area be larger than before with the 50mm lens ?

11-20-2005, 07:55 AM
Yes, shorter focal lengths at same apature and same distance will have greater DOF.

There are quite a few online DOF calculators if you want, both will be quite narrow wide open but a 50 more narrow then a 28.