FX to DX lens question

Started Nov 18, 2012 | Discussions thread
Billx08 Forum Pro • Posts: 11,373
Re: FX to DX lens question

Clear Blue Sky wrote:

At some point next year I am going to get a D600 as I long to get back to full frame (old days of film, pre-digital era most SLRs were full frame). The thing is I have now a small budget for a 35mm lens as well as a pressing need for a better standard zoom.I would really not want to invest in lenses now that I can't use later on a DX camera.

I am considering a Sigma 17-50 f2.8 and a Nikon 35mm f1.8. Would either of these work on a D600? Would my 50mm F1.8D work? If so in what capacity as I have heard that all FX lenses wil work on a D600 but cropped to a reduced size.

I don't have most of those lenses but I believe that the Sigma and the 50mm are both FX lenses and if so, they'll work very well on the D600. Whether the image is cropped or not is up to you since the D600's menu gives you several crop options. You can crop the image area even if you use FX lenses, you can use the full FX image area when DX lenses are mounted, or you can allow the D600 to automatically use the FX image area with FX lenses and the DX image area with DX lenses. If you use the D600's DX image area with Nikon's lenses (whether they're DX or FX lenses) you'll get the same images that you get using the same lenses on any of Nikon's DX DSLRs. The only difference is that the number of megapixels might be different because the D600's DX crop area gives you 10mp images. So if your current camera is a 6mp D40, D50 or D70, you'll get higher resolution photos using your DX lenses with the D600. If you're using a 10mp D40x or D80, the images will be about the same, except for the slightly higher image quality that the D600's more moderns sensor will provide. If you're using a 12mp camera such as the D90 or D300, then the D600's 10mp DX crop area will still give you excellent images, but at a slightly lower resolution.

One other point to make note of if you're not already aware of it (since you mentioned "I have heard that all FX lenses will work on a D600 but cropped to a reduced size") is that while the D600 won't crop images produced using FX lenses unless you choose to do so, the images will seem to be negatively cropped. That is, if you compare images shot with an FX lens on DX and FX cameras, due to the smaller DX sensor only seeing the central part of the lens's image circle, it would seem to be a longer focal length, but that's only if you enlarge the images to the same size. So a 200mm lens on a DX camera would produce images that resemble what you'd get with a 300mm FX lens on an FX camera. The opposite is also true, so if (I'm still not sure) the Sigma 17-50mm lens is an FX lens, then if you want to use it at 17mm to take indoor pictures in really cramped quarters, it might not go wide enough. But the same lens on an FX body will cover a wider area. Put another way, if you have two identical 17-50mm FX lenses and use one on a DX body and the other on an FX body, then if you have the one on the DX body set to 17mm, you'll get similar images if the lens on the FX body is set to 25.5mm, so the FX bodies can produce wider angle images using the same lenses.

Keyboard shortcuts:
FForum PPrevious NNext WNext unread UUpvote SSubscribe RReply QQuote BBookmark MMy threads
Color scheme? Blue / Yellow