FX lenses on a DX body

Qarik

I had a thought the other day. I kept hearing from different sources that using and FX lense on a DX body (say for example the 24-70mm 2.8 nikkor on a d90) doesn't make sense since you are "wasting" the full of scope of the lens.

I imageine FX lens on full frame sensor would be like shining flashlight on say 8x11 sheet of paper so the umbra of the light matches the size of the paper but FX lens on DX sensor is like shining the same light on say 6x9 sheet of paper so umbra of the light is beyond the edge of the sensor. Is that correct?

But that got me thinking..if the FX lens overextends the DX sensor then you also using the "sweet spot" of the lens all the time. There would be less border issues wrt to softness at edges or light fall off (maybe even chromatic abberation?). Is this not correct?

swintonphoto

Your thoughts are accurate for the most part. There are a few things to consider:
-FX lenses are typically larger than DX lenses. Hence, using FX lenses on DX bodies will make the setup a bit more cumbersome.
-It is true you will likely have fewer problems with light falloff, there are other complications that come into play.

Read this article to get an idea. While it talks specifically about 4/3 lenses, it should be applicable to other digital-specific lenses and does give good arguments as to why buying lenses specifically designed for each sensor will usually produce better results supporting using DX lenses with DX bodies:
http://www.four-thirds.org/en/about/benefit.html

Joves

I use FX/Film lenses on my D80 and D300 all the time. It really doesnt matter all that much and, in the case of long zooms is a benefit. I gain more reach that way. Now using a DX lens on a FX body is another thing.

ziggy53

"Crop" factor sensors and cameras really should be thought of as a different format that can conveniently use full-frame format lenses as well as lenses specifically designed for the crop system.

If you only intend to ever have one camera in your life then you should plan your lens purchases accordingly. If you plan on have a mixture of camera format types then your strategy might change as well.

What I "recommend" is the purchase of tools that meet your needs, and then moderate future sales and purchases based again on your needs at that time.

Cygnus Studios

ziggy53 wrote:

If you only intend to ever have one camera in your life then you should plan your lens purchases accordingly.

Exactly.

DX glass works best on DX sensors.

FX glass works on everything.

I see loads of ads for DX glass when the decision is made to go full frame. I know that Nikon is currently making more DX glass to help the market, but it seems like a dead end to me. Why limit yourself when you don't have to.

catspaw

not to get off topic, but rather make this discussion more robust -- HOW does Nikon identify their FX lenses, since they seem to shy away from the 'FX' abbreviation although embrace DC. I'm going FX in the future, but have no notion what's out there because I simple cannot tell. bythom.com is a bit outdated on this, which is my normal source of information.

ziggy53

catspaw wrote:

not to get off topic, but rather make this discussion more robust -- HOW does Nikon identify their FX lenses, since they seem to shy away from the 'FX' abbreviation although embrace DC. I'm going FX in the future, but have no notion what's out there because I simple cannot tell. bythom.com is a bit outdated on this, which is my normal source of information.

FX is not included as a lens designator in the Nikon lens lineup. If a lens is genuine Nikon and does not have a DX in the full name of the lens, then I believe it is an FX/full-frame lens by default.

You can always check Nikkor lenses at the Nikon website:

http://www.nikonusa.com/Find-Your-Nikon/Camera-Lenses/index.page