Nikon D40 cannot focus to infinity with manual focus prime lens

Discussion in 'Digital Photography' started by zc94123, Aug 14, 2007.

  1. zc94123

    zc94123 Guest

    I have a D40 and manual focus Kiron 105mm macro prime lens. I cannot
    focus to infinity on the D40(all manual mode and focus of course).
    Focus perfectly on old FM2 Nikon 35mm.

    Can anyone get their 105mm to focus to infinity ?

    I have seen on the web that no prime manual lens can focus to infinity
    on the D40. But my 55mm f1/8 seems ok. So, is this a macro lens
    problem or something else ?
    zc94123, Aug 14, 2007
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  2. If you mean fixed focal length, that's already implied by the "105mm."

    I don't understand this. Do you mean you can't turn the focusing ring on the
    Kiron to the infinity mark, or you can but you don't believe it's really
    focused on infinity? (In either case, why?)

    The correct short way of saying fixed focal length is FFL.

    That's nonsense. If a manual focusing lens can focus to infinity on any
    other Nikon, it can do so on the D40 too.

    Dunno what's going on with your Kiron, but there is no such macro lens
    problem with the D40.

    Neil Harrington, Aug 14, 2007
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  3. zc94123

    Jim Guest

    It is probably the lens. After all the other lens works OK.

    Jim, Aug 14, 2007
  4. zc94123

    tomm42 Guest

    Is this an AI or AIS mount? Could be an older copy this lens was
    produced for 20 years or so. If it is not an AI mount it could be
    sitting wrong on your camera, non AI lenses have the potential for
    damaging Nikon DSLRs. O ther than that the lens could be damaged in
    some way.

    tomm42, Aug 15, 2007
  5. zc94123

    zc94123 Guest

    I got the info that old manual primes cannot focus to infinity on
    nikon digitals from here :
    "manual focus lenses cannot focus to infinity on Nikon digital SLR's
    so they are out too."
    I emailed that guy and he confirmed it.

    If the distance from sensor to back of lens on a digital is different
    from that of the old 35mm films then you will not be able to focus to
    infinity. It has the same effect as putting an extension ring onto a
    lens on any camera, you lose the infinity focus ability.

    I can turn the focus ring fully to infinity on the D40.

    If the lens was defective it would not focus to infinity on my FM2.(?)

    here is the specs of the lens :

    So the question still remains.....
    zc94123, Aug 16, 2007
  6. I think you misunderstood what he said. He's talking about *Olympus* lenses
    when he says they "cannot focus to infinity on Nikon digital SLR's."
    Evidently he means by using an adapter, since he has a lot of "wonderful
    Olympus OM lenses that [he] would like to play with." That is undoubtedly
    true, since an adapter necessarily puts the lens farther from the film
    plane, meaning (depending on the flange to film distance of the example) the
    lens can only be used for close focusing.

    But it is not. How could it be? It wouldn't make any difference whether the
    lens were manual focus or autofocus, if the flange to film distance were
    different it wouldn't work as intended.

    Exactly. That is *not* the case with Nikon digital SLRs.
    Well, it seems to me the question is, Why do you think the lens is *not*
    focusing to infinity when you can turn the focus ring to infinity? If it
    reaches infinity on your FM2, it will reach infinity on the D40 also. There
    is no difference in the flange to film distance between the two cameras.

    Neil Harrington, Aug 16, 2007
  7. zc94123

    Jim Guest

    Nonsense. Both of my AI-S lenses will focus to infinity and anywhere else
    on my D70.
    These lenses also focus to infinity and anywhere else on my F2 and F3.
    I convert my 300 f4 AF lens to AI-S by connecting it to a 2x converter.
    This configuration
    works as well as it can on both the F3 and D70.

    One problem you will have with your D40 is that it can only control the
    fstop with a G lens.
    This means that all other lenses definitely have limited usefulness.

    Jim, Aug 16, 2007
  8. zc94123

    zc94123 Guest

    OK, it must be the lens that is defective . At least I know now that
    the D40 should be able to handle it.

    zc94123, Aug 17, 2007
  9. zc94123

    Mark Sieving Guest

    That's not true. The D40 meters and controls the aperture with any AF
    lens. For non G type lenses, with the aperture ring on the lens, you
    just lock the aperture at the smallest setting.

    The exposure meter does not work for manual focus lenses (except the
    rare AI-P lenses, which contain a chip that provides lens information
    to the camera body) so you must use those in manual exposure mode.
    For that, you set the aperture using the ring on the lens.

    There used to be some people who could add the lens information chip
    to some manual focus lenses, so that newer cameras could meter with
    them. I don't know if those folks are still in business.

    The D40 will only autofocus with AF-S type lenses, which have the
    autofocus motor in the lens.
    Mark Sieving, Aug 17, 2007
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