!.5 x Digital Gain?

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  • 02-20-2006, 08:03 AM
    HRZag
    !.5 x Digital Gain?
    I have a Nikon D100 and am looking to buy the 70-200 2.8 lense. Will I get the benefit of the 1.5 power gain of the lense or is this lense built for digital and so, will give me maximum of 200mm focal length. (as older film to digital lenses do)

    Sorry if my terminology isn't correct, I hope you know what I mean.
  • 02-20-2006, 09:49 AM
    Franglais
    1.5 crop
    Quote:

    Originally Posted by HRZag
    I have a Nikon D100 and am looking to buy the 70-200 2.8 lense. Will I get the benefit of the 1.5 power gain of the lense or is this lense built for digital and so, will give me maximum of 200mm focal length. (as older film to digital lenses do)

    Sorry if my terminology isn't correct, I hope you know what I mean.

    Usually we call it "crop factor" because in fact you're only using the center part of the image. And yes your 70-200 f2.8 will give you an image equivalent to a 105-300mm f2.8 (in film terms).

    Charles
  • 02-25-2006, 03:40 PM
    another view
    Re: !.5 x Digital Gain?
    A lens is always only one focal length (or range of focal lengths in the case of a zoom). Putting it on a DSLR with a 1.5x crop factor does not change the focal length; it crops the sides out. Think of it this way - take an 8x12 print and with a pair of scissors, turn it into a 5x7.

    This isn't a DX lens, but even if it was it would still be whatever focal length on a film camera. DX lenses usually won't work well on a film camera because they're made to work with the smaller DSLR sensor. What will happen is that the edges of the frame will be black because the image projected on the film isn't quite as large as the film (but it is larger than the sensor so you won't have this problem). People shooting other film formats in the past were used to this - a 50mm lens on a 35mm camera gave roughly the same angle of view as an 80mm lens on a 6x6 medium format Hasselblad, or about a 210mm lens on a 4x5 large format camera.