I just wanted to know this, but why did camera companies produce digital only lenses, knowing they would have drawbacks on full frame bodies, or not work at all!? Is it just to make them lighter!? Or what!?Www@QuestionHome@Com
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Position:Home>Visual Arts> What's With Digitally Cropped Lenses?Question: What's With Digitally Cropped Lenses!? I just wanted to know this, but why did camera companies produce digital only lenses, knowing they would have drawbacks on full frame bodies, or not work at all!? Is it just to make them lighter!? Or what!?Www@QuestionHome@Com
Best Answer - Chosen by Asker: Smaller and cheaper, believe it or not!. This is all relative, though!. Why have full frame coverage if the sensor is "only" 2/3 as wide!? You can use less glass to cover a typical (non-FF) sensor!. I'm going to try to find some comparisons!.!.!. Okay, these are not direct comparisons, but they might give you an idea!.!.!. Nikon 17-55 f/2!.8 DX lens: Length: 4!.4" Diameter: 3!.4" Weight: 1!.6 lbs Price: $1,200 Nikon 17-35 f/2!.8 full frame lens: Length: 4!.2" Diameter: 3!.7" Weight: 1!.66 lbs Price: $1,500 Okay they are VERY similar in size, but note that the full format lens only zooms to 35 mm and the DX lens zooms to 55 mm!. Since aperture is a ratio of diaphragm opening to focal length, if the FF lens went to 55 mm and if it maintained f/2!.8, it would have to be about 150% bigger in diameter - if my math serves me!.!.!. Zoom lenses deal with "effective" diameters and I don't know how they work their magic in those formulas!. These two are obviously not comparable beause on is a full stop faster, but they are not too far off from each other!.!.!. Nikon 12-24 f/4 DX lens: Length: 3!.5" Diameter: 3!.2" Weight: 1!.1 lbs Price: $859 Nikon 14-24 f/2!.8 full format lens: Length: 5!.2" Diameter: 3!.9" Weight: 2!.2 lbs Price: $1,590 How about if we compare "effective" lengths!? It is practically meaningless, but why not go out on a limb!. The ubiquitious 18-55 DX lens would give an equivalent focal range of 27-82!.5!. There is a full format lens of 24-85, which is almost the same coverage on a full format sensor as the 18-55 is on the DX sensor!. In other words, if you wanted the moderate wide-to-moderate tele in the digital world, you would want the 18-55!. For the same coverage in the full format or film world, you would want the 24-85!. These are not fair to compare, because the FF lens is 2/3 stop faster and might have a better build quality, but still they are not worlds apart!. Just look at the difference in size alone: Nikon 18-55 f/3!.5-5!.6 DX lens: Length: 2!.9" Diameter: 2!.7" Weight: 6!.8 OUNCES Price: $120 Nikon 28-85 f/2!.8-4!.0 full format lens: Length: 3!.2" Diameter: 3!.1" Weight: 1!.2 POUNDS Price: $500Www@QuestionHome@Com |