Switch to English Language Passer en langue française Omschakelen naar Nederlandse Taal Wechseln Sie zu deutschen Sprache Passa alla lingua italiana
Members: 71,568   Posts: 1,573,488   Online: 811
      
Page 2 of 3 FirstFirst 123 LastLast
Results 11 to 20 of 26
  1. #11
    paulie's Avatar
    Join Date
    Jul 2008
    Shooter
    Large Format
    Posts
    266
    i used a 6 second exposure on a test sheet of paper and the problem is there still, ive removed the filter and attached a hood, no change in hot spot

    so i dont think it can be shutter blade problem

    it seem to get worse as the lens gets stopped down

    f11 is ok f22 hotspot

  2. #12

    Join Date
    Dec 2009
    Shooter
    4x5 Format
    Posts
    127
    Hi Paulie,

    Do you still have the original mount for the Componon? If the flange-to-flange distance between the front and rear capsules of the lens is incorrect it may explain the hotspot and the overall softness that I think I can see?

    There's probably someone here who would know without even checking - but it's not me!

  3. #13
    paulie's Avatar
    Join Date
    Jul 2008
    Shooter
    Large Format
    Posts
    266
    yes i have checked the overall spacing against the original mount and they are very close perhaps .2mm difference, would this be enough to create this hotspot?

    i am very close to mounting my pinhole now and ditching the lens which would be a shame as the camera i have built is really a little complex for just a pinhole

    plus i already have a wide angle 10 x 8 pinhole

    any suggestions for a 210mm (compur 1) that will cover my film and will fit in with my tiny budget?

  4. #14
    erikg's Avatar
    Join Date
    Feb 2003
    Location
    pawtucket rhode island usa
    Shooter
    Multi Format
    Posts
    1,433
    I had a similar issue with a pinhole type crack in a lensboard. Drove me nuts, but a buddy helped track down the problem. So I think Victor might be on to something about the shutter. It may be hanging up, and that could happen inconsistently, so testing may not catch it at first. Maybe it only happens at slower speeds. We had a shutter like that in the studio, but it didn't matter there because we shot with strobes. It wouldn't take much, a tiny crack that wouldn't be so obvious.

  5. #15
    paulie's Avatar
    Join Date
    Jul 2008
    Shooter
    Large Format
    Posts
    266
    i use the same lens board with another lens and have no issues, it is definitely a lens issue i think, my final test tomorrow will be to unscrew the front element a turn or two ,if this doesnt help then the lens will be retired i think

    my shutter speed is generally long over a minute , therefore shutter hang isnt a issue, and i know the shutter is reliable as i use it for other lenses with no ill effect

  6. #16
    erikg's Avatar
    Join Date
    Feb 2003
    Location
    pawtucket rhode island usa
    Shooter
    Multi Format
    Posts
    1,433
    The shutter hang up would be between exposures, where it is not closing all of the way all of the time, so that you are getting a small amount of additional exposure.

  7. #17
    paulie's Avatar
    Join Date
    Jul 2008
    Shooter
    Large Format
    Posts
    266
    i will try another of my shutters and get back to you on this, generally i lens cap after a exposure as it is a one shot machine

    oops i forgot i have tried this already ( tried different shutter) with no change to the hot spot

    i just think enlarger lenses are a no go for regular shooting

  8. #18
    paulie's Avatar
    Join Date
    Jul 2008
    Shooter
    Large Format
    Posts
    266
    one weird thing i have noticed is that this 210mm lens is actuall focusing at infinity at roughly 205mm and not 210mm

    any thoughts here?

  9. #19
    erikg's Avatar
    Join Date
    Feb 2003
    Location
    pawtucket rhode island usa
    Shooter
    Multi Format
    Posts
    1,433
    Actual focal length rarely matches the marked focal length exactly, nothing too strange there. There isn't anything wrong with using enlarging lenses for shooting as such, pretty common for close up work. Hope you can figure it out, it looks like a pretty neat camera.

  10. #20
    paulie's Avatar
    Join Date
    Jul 2008
    Shooter
    Large Format
    Posts
    266
    thanks for your help

    i will test the lens spacing i think then i will rest :0)

Page 2 of 3 FirstFirst 123 LastLast


 

APUG PARTNERS EQUALLY FUNDING OUR COMMUNITY:



Contact Us  |  Support Us!  |  Advertise  |  Site Terms  |  Archive  —   Search  |  Mobile Device Access  |  RSS  |  Facebook  |  Linkedin