Crop Factor Help?

[Mentalblock]

I'm looking at getting myself a prime lens.
Currently I've got my eye on the Nikon 50mm f/1.8 D AF, but on the D90 will that make it about 75mm, ie 50mm times the crop factor?

If so, would I be better going for the Nikon AF-S 35mm f1.8 G DX Lens to keep closer to the 50mm after the crop factor.

Also, for comparison, is my 18 - 105 kit lens actually 18 - 105, or is that also affected by the crop factor?

 

[scottthehat]

depends what you want to take pics off, the 50 on a 1.5crop is ok for portraits but not wide enough really so 35mm is better for that repect. and your 18-105 is in 35mm terms 27-157.5mm

 

[Flash In The Pan]

Set your kit lens to 50mm, take a picture. Then set it to 35mm, take the same pic. Compare. Buy the lens that will provide the version you like best.

 

[Mentalblock]

depends what you want to take pics off, the 50 on a 1.5crop is ok for portraits but not wide enough really so 35mm is better for that repect. and your 18-105 is in 35mm terms 27-157.5mm

Set your kit lens to 50mm, take a picture. Then set it to 35mm, take the same pic. Compare. Buy the lens that will provide the version you like best.

Thanks for the comments

So, what I get from 50mm on my kit lens is what I'll get from the 50mm prime?

I'd like to do portrait, but it's the DOF I want from the prime .too

 

[Flash In The Pan]

Thanks for the comments

So, what I get from 50mm on my kit lens is what I'll get from the 50mm prime?

I'd like to do portrait, but it's the DOF I want from the prime .too

Yes, 50mm is 50mm, regardless of the lens, all you'll get from the prime is (apart from a brighter viewfinder image) the ability to shoot at a larger aperture.

 

[Shine On]

The crop factor is referring to your camera's sensor, not the lens. So any lens on your camera, at a given focal length, will give the same field of view - e.g. 50mm on a prime is same as 50mm on a 18-105 kit lens, same as 50mm on a 50-500 superzoom, etc.