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Old Dec 25, 2005, 12:54 PM   #1
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I am thinking of buying a digital SLR. When I look at, say, a 28 - 200 zoom lens is the effect of the digital camera going to be to multiply the zoom by 1.5 and thus yield a 42 - 300 zoom? If the answer is yes, does this apply to lenses made for digital SLR's such the Nikon DX or the Minolta DT lenses?

Thanks in advance for any help and Merry Christmas to all,
Mike in Vermont
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Old Dec 25, 2005, 3:05 PM   #2
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It does as long as the camera has the crop factor (1.5 or 1.6). Some cameras have full frame sensors
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Old Dec 25, 2005, 8:31 PM   #3
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Yes, with the crop factor a 28-200 would become a 42-300 (at the same f stop).

The crop factor does NOT apply to KM's DT series lenses as they are designed for the APS-C size sensor - these lenses WILL NOT WORK (properly) on a KM film camera.

IF the DSLR has a full frame (36x24mm) sensor there would not be a crop factor.
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Old Dec 25, 2005, 9:55 PM   #4
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Quote:
The crop factor does NOT apply to KM's DT series lenses

Wait, even on lenses made for digital SLRs, isn'tthe equivalent focal length still ~1.5 times the real focal length? Unless the digital-only lens you mention only specifies its equivalent focal length and not the real focal length. An 18-125 lens is an 18-125 lens (it just might not project an image that covers the whole area of a 35mm sensor), but any 18-125 lensgives you the field of view ofa 27-190 (approx.) when on an APS-sensor DSLR.
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Old Dec 26, 2005, 7:40 AM   #5
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Correct. The "designed for digital" lenses with smaller image circles still give you a narrower angle of view when used on a DSLR with a smaller sensor, compared to the same focal length lenses on a 35mm body.

So, to see how the Konica Minolta DT lenses, Nikon DX lenses (or any other lenses) compare to using the same focal length lenses on a 35mm body, you still need to multiply the actual focal length by 1.53x when using them on DSLR models from Nikon, Konica Minolta or Pentax.



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Old Dec 28, 2005, 9:12 AM   #6
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True enough - but keep in mind those DT or DX lenses will NOT work on a camera body with a full frame sensor. You may think "who cares - those are only pro cameras" but look how fast the DSLR market is moving. It was only 2 years ago or so that the $1000 price barrier was broken for DSLRs - and recently cameras with a full size sensor have started to come down in price. In general, what I'm saying is a good lens will last longer than your camera body so keep this in mind if you are deciding whether to get a designed for digital lens.
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Old Dec 29, 2005, 11:37 AM   #7
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JohnG
Are you sure about that statement. I'm sure as sure can be that the DX lenses on Nikons will work with a full framed DSLR. You just don't have to and the magnication rate of 1.5 or 1.6.
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Old Dec 29, 2005, 2:39 PM   #8
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The 'digital' (DX etc...) lenses may work on a full-frame, but they will vignette (darkening of corners) because of the smaller image circle!
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Old Dec 30, 2005, 2:53 AM   #9
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It is possible to be sure as can be and completely wrong at the same time.


CaliBoy wrote:
Quote:
JohnG
Are you sure about that statement. I'm sure as sure can be that the DX lenses on Nikons will work with a full framed DSLR. You just don't have to and the magnication rate of 1.5 or 1.6.
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Old Dec 30, 2005, 3:55 AM   #10
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:-)I sure am :-)
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