Sapphire film recorder (focusing)

Discussion in 'Film and Processing' started by slugger415, Apr 12, 2019.

  1. Hi all, I'm new here, and apologies if this is way off topic. I just got an old Sapphire Film Recorder, which seems to function well, but when I got my first roll of test film back from the lab it was out of focus. I think I've figured out how to adjust the lens, but I don't see any way to focus on an image - any tips? I did see a brief mention of this device in a forum topic here from a few years back so hopefully I'm not totally off base. Thanks much, Scott
  2. Years ago, the lab I was with bought a film recorder (not sapphire). I remember lots of problems
    with it, and don't remember ever seeing good results. I don't remember focus as the
    problem, most had to do with it doing anything at all. Like the shutter not opening, or
    film not winding.

    About the only way that I would know, would be to put some focus screen in the back of
    the camera, and adjust the focus while looking at the screen, possibly through a
    magnifying lens.
  3. Yep, you need to take the back off the thing and stick a ground-glass on the gate.

    It should be a one off adjustment as long as the CRT, or whatever you're recording, is fixed to the camera.
  4. The ones I know, image a CRT through color filters, and scan somewhat slowly
    though the image. I don't know what it actually looks like from a ground glass, but
    yes, I think that is what you need to do. Presumably in a dark room.
  5. Thanks all for the suggestions. Unfortunately the back doesn't look like it comes off easily (I'm wondering if there was a prism system like old optical printers used), and there's nothing to focus on unless an image is being projected, which I believe requires film to be loaded... catch-22! But there must be a way, I'll keep tinkering, thanks!
  6. I think Joe meant to open the back like while you loading the film. Then put a piece of ground glass at the film gate.
  7. Management Graphics 700376 Sapphire Precision Color Slide Recorder, 100-240 V . Kellan Inc

    seems to have some pictures, which don't make it easy to figure out.

    It might be that you remove some part to get to where you put the ground glass.

    Also, I wonder if they put in a filter to darken the image, so as not to overexpose
    the film. One that I know scan pretty slowly, so it might be too dark to see.

    It would seem that they might have a calibration and focus mode, where it would
    work differently from ordinary recording mode.
  8. Right, there is no "camera" per se, just a threading mechanism.
  9. It's a light-tight box with a lens and a film plane; that's a camera.
    It looks as if the pressure plate can be removed for focussing. You'll maybe need to remove the "out of film sensor" too.

    The film sensor is just going to be a microswitch or optical sensor, which can easily be tricked or defeated in order to kick the thing into life without using film.

    A makeshift focussing screen can be fashioned by rubbing a strip of 'magic' adhesive tape onto some thin glass - such as a microscope slide. The stippled surface of the magic tape acts like a finely ground glass.
  10. I always wondered about a good substitute, since I usually dont' have actual ground glass.

    You need one close to the width, in this case 35mm, of the film path.

    Interesting design, though. It looks like it can take a larger film spool on the left, then spool
    into a removable cartridge on the right. You can then cut of and process film from the right,
    any time.

    With 35mm cartridges, do you move the sensor up, and open the pressure plate
    to get the film through?
  11. The LaserGraphics film recorder has what looks more like a camera, which is removable,
    and loads like most 35mm cameras. As well as I remember, it looks slightly less camera
    like, as I don't remember the part that looks like a viewfinder on top. This is what I
    thought you might also have something similar to.

  12. I had an afterthought about the focus.

    You also need to make sure the CRT beam is properly focussed. If the beam is fuzzy, then obviously no amount of lens adjustment will put it right.

    CRTs were/are horrible things to keep working with maximum definition. All the voltages need to be right, all the focus coils and magnets need to be properly aligned, and the cathode, heater filament and phosphor target all need to be in good condition. Any one of the above being out of spec can enlarge the spot size and lose definition.

    And that's why we all have LCD monitors and TV sets these days!
  13. Well, they aren't so hard to get right, but certainly that is also possible.

    For color CRTs, convergence is a big complication, but usual film recorders use a white CRT and color filters, doing three passes over the image.

    An additional complication of TV sets is the large deflection angle to make the set not so deep, but the screen wide.
    The Lasergraphics recorder that I noted has a very long, relative to the screen size, CRT, such that the deflection angle is small.
    I can't tell from the picture how the Sapphire works. The OP didn't indicate if the focus varies across the image.

    Otherwise, there should be one adjustment, for the focus electrode voltage.

    If one is able to adjust the focus lens, and finds a minimum spot size that isn't small, then yes check CRT focus.

    I suppose one could figure out how to directly view the CRT screen to adjust CRT focus.

    Best would be to find a service manual, with the proper adjustment methods.

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