FX 17mm Focal Length
I often wondered, "Is the 1.5x crop factor real with "DX" sensors?" I set up a test to find out. Placing my sturdy Manfrotto tripod on our deck, I went about scribbling on half sheets of paper the lens and focal length being used. Here, I used "D" to signify a "DX" lens and the absence of the "D" indicates an "FX" ("full frame" or "film" et cetera) lens. The color images were shot with my Nikon D80 using the same settings as on my N80 throughout the test (I forgot to kick the ISO down to 125, so they are a bit overexposed -- however, exposure or image quality was not the intent of this test). The black and white shots are scans from a contact sheet I made in the darkroom (hence the poor quality). So, in color is a DX sensor and black and white a flim (or FX like a D700, D3 (Nikon) or 5D, 1D (Canon)).
Here is my FX (film) lens at 17mm on my DX camera (D80) and my N80 film camera. Notice how the D80 looks like it zoomed in -- it didn't. Same focal lengths. The physics of this is very explainable but not here but a quick search will yield a much simpler explanation that I can provide here. While the 1.5x crop factor is good for getting a 300mm film-equivalent focal length out of a 200mm lens, the gain on the long end is sorely missed on the ultra-wide angle. On a DX camera, my 17mm setting becomes equivalent to about 25mm on my film camera -- or future FX digital :)
FX 17mm Focal Length
I often wondered, "Is the 1.5x crop factor real with "DX" sensors?" I set up a test to find out. Placing my sturdy Manfrotto tripod on our deck, I went about scribbling on half sheets of paper the lens and focal length being used. Here, I used "D" to signify a "DX" lens and the absence of the "D" indicates an "FX" ("full frame" or "film" et cetera) lens. The color images were shot with my Nikon D80 using the same settings as on my N80 throughout the test (I forgot to kick the ISO down to 125, so they are a bit overexposed -- however, exposure or image quality was not the intent of this test). The black and white shots are scans from a contact sheet I made in the darkroom (hence the poor quality). So, in color is a DX sensor and black and white a flim (or FX like a D700, D3 (Nikon) or 5D, 1D (Canon)).
Here is my FX (film) lens at 17mm on my DX camera (D80) and my N80 film camera. Notice how the D80 looks like it zoomed in -- it didn't. Same focal lengths. The physics of this is very explainable but not here but a quick search will yield a much simpler explanation that I can provide here. While the 1.5x crop factor is good for getting a 300mm film-equivalent focal length out of a 200mm lens, the gain on the long end is sorely missed on the ultra-wide angle. On a DX camera, my 17mm setting becomes equivalent to about 25mm on my film camera -- or future FX digital :)