35 or 50mm?

[Orbster]

Hi all, I'm thinking of buying a small prime lens for my Nikon D5000 and unsure what would be best.

I have done a little bit of reading about both and the general consensus seems to be that a 35mm gives the equivalent of a 50mm on 35mm format but I am wondering whether the wider aperture on the 50mm would make for more pleasing photo's in the end?

I would like to be able to do more photo's indoors of my family and also I believe the wider aperture will give me sharper pictures outside too?

Any advice?

[chris-p]

Originally Posted by Orbster

I have done a little bit of reading about both and the general consensus seems to be that a 35mm gives the equivalent of a 50mm on 35mm format

Sort of... Technically there are 2 things which the 50mm lens was supposed to be (and was never quite either). You can talk about the normal field of view which is supposed to be the closest you can get to the human eye. Of course, the eye has a relatively narrow field of view and our brains fill in the rest. In 35mm terms, the focal length that most closely matches the human eye is about 47mm.

The other thing is the normal focal length. This is different from the normal field of view. The normal focal length is the same as the diagonal measurement of the image plane. 35mm film was 36mm wide and 24mm high so the diagonal size (according to Pythagorean theory) is 43.27mm. The normal focal length is preferable because you have to do as little to the light path to make it fit over the sensor/film so you get less distortion and aberration in just about every way.

Personally, I prefer 35mm. It's closer to the normal field of view, which means more natural looking perspective, and it's closer to the mathematically normal focal length, which means less geometric distortion.

Originally Posted by Orbster

but I am wondering whether the wider aperture on the 50mm would make for more pleasing photo's in the end?

Depends which 50mm lens you're looking at. The Nikkor 35mm is an f/1.8 and you might be looking at a 50mm f/1.4 which would certainly be more expensive.
If you've only ever had a kit lens which doesn't go wider than f/3.5 you'll be shocked by f/1.8 and the tiny depth of field. The main thing you'd gain from an f/1.4 is build quality, but not really any significant extra light gathering capacity.

Originally Posted by Orbster

I would like to be able to do more photo's indoors of my family and also I believe the wider aperture will give me sharper pictures outside too?

A monofocal lens will give you sharper pictures than a zoom lens, but it has nothing to do with the wider aperture. The extra aperture will let you shoot in lower light without having to boost up the ISO as much and let you play with shallow depth of field effects.

[Orbster]

Ok thanks for the reply.

I've gone for the 50mm AF-S 1.4. Should be getting it tomorrow