IR film in Fujifilm GA 645zi camera?

Discussion in 'Medium Format' started by jim_kenty, Jul 1, 2010.

  1. Has anyone shot infrared film in this camera? I'm thinking of trying it, but have heard that AF cameras would fog the film. Could not find any reference in Fuji IB.
     
  2. It's not AF that may fog the film but an infra red film advance system. With 35mm it counts the sprocket holes but with 120 I don't see how IR could be used to judge film position so it's probably o.k.
     
  3. I have shot Ilford SFX 200 with my Fuji GA 645 zi with no fogging problems (ie any internal IR frame registration etc. has not been registered)
    Exposure and focus are a little complicated though, auto focus and obviously exposure will be of little use, you're into the manual settings which are roundabout at the best of times with this camera, which is marvellous with conventional neg stock.
    I'm not sure of fully IR film, I would try it though.
    Regards - Ross
     
  4. Want to try this in my GA645 (no zoom, fixed). I am not concerned about fogging but about the focus.
    Obviously the GA will focus for visible wave lenghts. Will I have unsharp images if I use the AF (the GA is practically not manual focusable) with the SFX 200 and a deep red or even IR (up tot IR72) filter?

    For exposure I would set the ISO manually (ISO 6?) and use manual exposure or (perhaps) aperture priority.
     
  5. AFAIK autofocus isn't exactly working on infrared film. But I might be wrong. As for the sharpness, if stop down beyond f/8, you should be fine in most situations (street, landscape) thanks to deeper dof.

    Wouldn't recommend aperture priority or anything automatic at all. Because I doubt it can work properly with so much light cut-off thanks to IR filter
     
  6. There is no cut of at all, as said it does not focus or measure light trough the lens. The entire exposure and autofocus system is separate and will not be behind the filter.
     
  7. I'd still be careful Sir. Some people say it fogs the film. Others say it doesn't. Some say autofocus isn't reliable as well as automatic exposure system. But it's worth mentioning that some of those are 645Zi and others are simple 645. I hope someone more qualified will show up and spread a light on this matter.
     
  8. I think you misunderstood what you quoted from me.
    I refered to the fact, that the IR filter will not influence the capability to measure light, being that the camera measures light not trough the lens and therefore enough light is there for AE, the IR filter cutting no light from the light senzor as it does not cover it.

    Regarding focalising, the problem is that IR has another wavelenght than visible light, therefore you need to extend the lens a bit more so that the image is still formed on the film plane. On classic lenses you have a red dot and after focalising in visible light you rotate to the red dot, that compensate the difference in where the lenght of IR will form the image. But on the GA series you dont twist the lens manually.
     
  9. Wow!
    A 3 year delay on a response. That's got to be some kind of record.
     
    mag_miksch likes this.
  10. I suspect not, but oh well.

    So we don't get to find out?

    As far as I know, the currently available films go barely into the IR.

    Though lenses designed to minimize chromatic aberration in the visible can
    change pretty fast outside that range.

    IR LEDs and silicon phototransistors are pretty far in to the IR, so I suspect
    way past the current films.

    I do sometimes miss those films that they made for government agencies.
     

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