I'm confused after reading the question and the first reply. The asker asks,
I'm becoming more interested in landscape photography and want to add to my Nikon DSLR a wide angle lens, but I dont really understand what this means. According to Wikipedia (not the most reliable source I know!) common wide angle focal lengths are 35, 28, 24, 21, 18 and 14mm.
So this does this mean that the kit lens that comes with the Nikon (18-55) is considered to be wide angle at the shorter focal length?
Also, what is the difference between ultra-wide and normal wide angle? And would an ultrawide be useful for landscape photography?
The first reply says,
On a crop sensor body (DX) that lens has a focal length of 27-82mm
The question doesn't mention about the type of camera body (DX/FX) or lens (DX/FX). To my knowledge, for the explanation to be true, it has be an 18-55 FX lens mounted on a DX camera body. Can't then only the crop factor (1.5X) kick in? But, 18-55 FX lens does not exist in Nikon lineup.
The way I understand crop-factor is that a 12mm lens mounted on an FX body will provide the same field of view of an 18mm lens mounted on a DX body, provided the distance between camera and subject remains unchanged. Going by the logic, the reverse should also be true, i.e. an 18-55 DX lens on a DX body should be equivalent to 12-35 FX lens on a FX body.