A "What If" question regarding the D400...
Time to upgrade my D200 so I've been patiently awaiting release of the D300 successor. A number of posts predict that the D400 might be full frame. If that's the case, would the focal range of my Nikkor 17-55mm lens be 17-55mm or 26-83mm?
#1. "RE: A "What If" question regarding the D400..." | In response to Reply # 0greenwing Registered since 18th May 2006Sun 15-Apr-12 01:28 PM | edited Sun 15-Apr-12 01:36 PM by greenwing
It would be 17-55. It can't change, and won't change. On an FX camera, it will not fill the full frame, because it's a DX lens, so the best mode to use might be DX. Then your image will look similar to what you get from the D200.
If it was an FX lens, and you put it on an FX camera, you would see what you (as a DX user) might mistake for an 11-36mm lens. You're used to seeing a crop from the middle of the image that an FX lens projects.
The lens itself does not change; it's the camera format that changes.
#3. "RE: A "What If" question regarding the D400..." | In response to Reply # 1RABaker Registered since 30th Sep 2003Sun 15-Apr-12 05:33 PM
Chris is correct. To put it in other words: Your D200 has a DX-size sensor (also called APS-C). The 17-55 is a DX lens - it projects an image circle intended to cover the smaller DX sensor. *IF* the 17-55 could cover the whole FX frame over its entire zoom range, it would give you a wider angle of view on an FX camera than you are used to on a DX camera - hence Chris' comment that it might appear to be an 11-36mm lens, because you would be using your DX camera experience as the basis for comparison. Since the 17-55 cannot adequately cover an FX sensor (at least not at all focal lengths) you would see **severe** vignetting with an FX camera. However, I believe that so far Nikon has made their FX cameras so that they automatically crop to a DX size if you mount a DX lens (although the photographer may be able to override this feature?). So if you put the 17-55 on an FX camera in its DX mode it will actually give you an image that looks essentially identical to what you are used to - except it will almost certainly have a different number of pixels in the cropped image than your D200 provides.
On a broader note, a lens focal length does not change when you move it from one camera to another. The focal length is a feature of the lens and has no direct connection to, or dependence on, the camera to which it is attached. Because of the size of the camera's sensor, however, the angle of view will change. Since so many photographers are/were used to the angle of view that they got with 35mm film cameras (and their "full size" frames), that angle of view was used as the standard when digital SLR cameras were introduced with smaller sensors. The smaller sensors (smaller than a standard 35mm film frame) gave less angle of view with the same focal length lens and, therefore, if one was used to the angle of view they got before, the lens seemed like it had a longer focal length. In fact, the focal length had not changed. It was just that the smaller sensor provided a smaller angle of view - a crop - when compared to "full frame." This distinction is important when considering such things as depth of field because a lens at a given focal length focused at the same distance and at a given aperture will yield essentially the same depth of field regardless of the size of the sensor (there is a small difference caused by the different size circles of confusion used for different size sensors).
#4. "RE: A "What If" question regarding the D400..." | In response to Reply # 3
#2. "RE: A "What If" question regarding the D400..." | In response to Reply # 0
The Focal length of the lens is 17-55mm and never changes. Only the angle of view changes due the "crop factor" of the smaller DX sensor.
Since the 17-55mm is a DX lens and projects a smaller image circle to the sensor plane than non-DX (FX) lenses, you will see vignetting (dark to black corners) when the lens is used on an FX body in FX mode.
Good Luck and Enjoy your Nikons!