New Ground Glass

Discussion in 'Large Format Cameras and Accessories' started by bmac, Oct 19, 2002.

  1. bmac

    bmac Member

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    I've got a rookie 4x5 question for y'all. I have a crack in the glass on my ORbit (tank) 4x5. Can I use any groundglass, or do I need a special type? Thickness, etc.

    Brian
     
  2. bmac

    bmac Member

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    Ok, not making sense this evening... I've been watching the baby all day, my brain is mush! My question basically is.. is Groundglass sold in standard thicknesses and sizes.

    Brian
     
  3. Jorge

    Jorge Inactive

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    I hate to sound like a smart ass.....well maybe not [​IMG].But why dont you measure the thickness of your glass with calipers and get one of the same size? I beleive glass for ground glass is 2mm thick. But I could be wrong so please check before you buy. There are a couple of guys in E bay making ground glass so maybe they can help you better. If worse comes to worse you can have 2mm glass acid etched and adjust with shims in your camera once you replace it. Easiest way to do it would be to remove the back, take a tootpick and measure the depth of the GG. make a mark on the tootpick and when yo replace the GG adjust it until it has the same depth. Or, pay someone who knows what he is doing to do it for you..lol...
    Later, let us know what happend....
     
  4. EUGENE

    EUGENE Member

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    Brian, I think Calumet carries the replacement for that groundglass. They are easy to replace if you get the correct size and thickness. The metal clips that hold the groundglass can be bent, slightly, to accomodate different thicknesses of glass, up to a point. As long as you don't change the position of the ground surface, slight variences in thickness are O.K.
     
  5. David A. Goldfarb

    David A. Goldfarb Moderator Staff Member Moderator

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    The only potential problem would be if you have a one-piece fresnel/glass combination with the fresnel between the focusing surface and the lens. I don't think such things existed in the days of the Orbit, so it shouldn't be a problem. The focusing surface usually rests directly on the frame, sometimes with shims underneath it. As long as the focusing surface is in the right place the thickness of the glass isn't too important.