Ross Air Ministry Lens

Discussion in 'Large Format Cameras and Accessories' started by Fotoguy20d, Jun 22, 2010.

  1. Fotoguy20d

    Fotoguy20d Subscriber

    Messages:
    1,234
    Joined:
    Jan 23, 2008
    Location:
    NJ
    Shooter:
    4x5 Format
    I'm actually just guessing its a Ross lens since other than the Air Ministry marking and a type number, there's no manufacturer's info.

    The lens had two problems when I got it - haze between the elements and the aperture didn't work. The rear element assembly came out easily enough and by removing the set screw I was able to get between those and clean them properly - haze there is now gone.

    I was able to remove the front cell assembly by removing a set screw there and was then able to unthread the aperture control ring. The aperture itself is fine but the screw between the ring and aperture is sheared off. If I can't scrounge a small enough screw, I may just try a dowel or similar to re-establish that link-up.

    So, the remaining problem (sorry for being so long winded in getting to here) - there's a bit of haze between the front elements but I can't figure out how to disassemble them. Anyone?

    Thanks,
    Dan
     

    Attached Files:

  2. Ian Grant

    Ian Grant Subscriber

    Messages:
    18,123
    Joined:
    Aug 2, 2004
    Location:
    West Midland
    Shooter:
    Multi Format
    Air Ministry lens were made by various manufacturers, so while Ross might have managed a project the actual lens could have been sub-contracted & made by Dallmeyer, Wray, Aldis etc.

    Ross were given control of the Carl Zeiss factory in Mill Hill, London after the outbreak of WWI which made binoculars as well as some lenses, and seem to have had the lions share of AM contracts after that. They were the UK manufacturers of Zeiss & Goerz lenses prior to WWI.

    Ian
     
  3. Fotoguy20d

    Fotoguy20d Subscriber

    Messages:
    1,234
    Joined:
    Jan 23, 2008
    Location:
    NJ
    Shooter:
    4x5 Format
    Interesting. I wonder how much variability would there be between suppliers, or given that they would all be fairly high quality suppliers to begin with it would be part of the usual variability in the manufacturing process. From a list of Ross serial numbers I found on-line (and which has some fairly big gaps) this one is somewhere near the middle of the range between 1939 and 1947 if it is in fact a Ross (the seller listed it as a B&J portrait lens due to the lensboard - must have been some mighty disappointed viewers)

    Dan
     
  4. Ian Grant

    Ian Grant Subscriber

    Messages:
    18,123
    Joined:
    Aug 2, 2004
    Location:
    West Midland
    Shooter:
    Multi Format
    When I replied earlier I was sat outside harder to see the deep blacks in an image :D

    That's the Ross AM Wide angle, Ross made far better wide angles than all their UK competitors except perhaps TTH Cooke. It was probably fitted to an aerial camera originally, uncoated they are a bit prone to flare but when sat in a camera pointed at the ground there's no sky/sun to cause it. It's also why the apertures are restricted to f11.

    Ian

    Ian