Using non-CPU lenses and built-in flash on the D50

Discussion in 'Nikon' started by crowdspotting, Aug 14, 2005.

  1. I just bought a D50 and am happy to learn that my collection of AI-S
    lenses will work fine on the D50 body (of course, without metering).

    My question is: has anyone been able to use the built-in flash on the
    D50 with a non-CPU lens?

    The manual is a bit unclear about this topic. I realize that if a non-
    CPU lens cannot be controlled by the D50 body, the camera can't
    automatically adjust the aperture in response to the lighting

    What I'd like to do is just have the D50 fire the flash at full power
    and I can adjust the aperture on the non-CPU lens to suit my subject.
    Sounds odd, I'm sure, but I just want to know if you can get the on
    board flash to fire with a non-CPU lens.


  2. This isn't clear to me either from the Nikon brochure for the D50.

    If the camera's built-in flash allows setting it to auto-thyrister mode (which would require a sensor to signal the flash to quench as needed), it would simplify flash use with lenses that don't allow TTL metering.

    Otherwise, you'll need to find out whether the built-in flash can be set to full manual or guide number mode. This is more time consuming because you'll need to calculate distance from flash to subject, etc. But it's the way flash was used for years, and the way I still often use flash with my non-metering medium format cameras.

    If the built-in flash can't be used these ways you can buy a simple hotshoe mounted auto-thyrister flash or any hotshoe mounted flash that includes an auto-thyrister mode, even if it's primarily intended for TTL use.
  3. I'm not familiar with the D50, but the D70 has a manual flash mode that can be set to full or less power. With a D70 you go to the Set Up menu and set the CSM menu to detailed. Then in the CSM menu go to Flash Mode > Manual > Full Power. I use this all the time since several of my lenses are non-CPU manual focus lenses.
  4. Thank you so much for your answers. I guess I should have mentioned the real issue: I mount a non-CPU lens on my D50 and the built-in flash won't fire. In manual mode, I can't seem to find any combination of settings that triggers the on-board flash.

    I should have asked: Has anyone been able to get their D50 flash to fire with a non-CPU lens?

    Thanks :)

  5. The D50 CAN use the on-board flash with a non-CPU lens. It's undocumented, but I went to the camera's menu, under "pencil" icon, there is a Flash Mode setting which was set to "TTL" by default. By changeing that to "Manual", the flash fires regardless of what lens you have mounted.


  6. It surprises me that the D50 and D70 apparently needs CPU equipped lenses for flash exposure.

    My D100 gives ttl flash metering with any lens, with the same features I get with an AF lens without the D feature. Only the ambient metering is shut off when mounting a lens without electronics.
  7. Jim,

    Your D100 is a D-TTL body, while the D50 and D70 are i-TTL and use preflash to determine flash exposure, which means the flash system needs to know the lens info.
  8. Adam - the D100, D70, and D50 all use preflashes.

    The D100 uses D-TTL, it fires the preflash after the mirror is flipped up and the lens is stopped down, but before the shutter upens. It reads the reflection off the shutter curtain (which is painted white, to get a better reflection).

    The D70 and D50 use iTTL, the preflash is fired before the lens is stopped down or the meter flips up, and the reflection is read by the main metering cells in the prism.

    So D100 can do flash with a manual lens, because the lens is stopped down to whatever you've set the aperture collar to. D70 and D50 can't do this because the camera can't know what you've set the aperture collar to, so it can't compute the difference between its wide open reading and what you need when the lens does stop down.
  9. Thanks, Joseph. I really appreciate the explanation of why they behave different.
  10. Essentially, this reflects Nikon's approach that, if you have a bunch of old lenses, you're
    supposed to be buying their more expensive cameras to get better support for those lenses.
    The D40/D40x don't even have a body focus motor, for instance, while the D80 and up do
    (and the D50 did).

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