Super Chromega D4 focusing problem with 150mm enlarging lens

Discussion in 'Darkroom Equipment' started by Wendy Monahan, Mar 26, 2013.

  1. Wendy Monahan

    Wendy Monahan Member

    Messages:
    5
    Joined:
    Nov 9, 2011
    Location:
    Las Vegas
    Shooter:
    Medium Format
    Hello,

    I recently purchased a Super Chromega D4 with small, medium, and large format lens cones. I am having difficulty focusing 4x5 negatives. The cone is 5 1/4" but has a 135mm Rodenstock-Omegaron lens mounted on it. I have my easel raised up an inch as the manual instructs. I have done quite a bit of searching around for an answer as to why. I BELIEVE that it is because the cone (and the auto-focus rail) are for a 150mm focal length. I have a shorter unmarked 2 3/4" cone that came with this enlarger, but it must be for a different model enlarger as the circumference of the cone is slightly larger and doesn't fit. I was hoping that this cone, although too short probably, would at least allow me to focus. I have used the enlarger and the 50mm lens mount with 35mm with no focusing problems.

    So...

    I found on the classic enlarger site that a D3 requires approximately a 4 inch cone for the 135mm focal length lens. Nowhere in the Omega literature can I find a listing for proper focal length for each lens cone. I have tried registering and searching on this site but have been unsuccessful thus far.

    Most likely I will want to buy a superior lens to the Rodenstock-Omegaron, but I wanted to at least try it before I cast it aside to the useless lens pile.

    Can anyone tell me if I am correct in my assumption that the focal length is wrong. I don't want to go ahead and buy yet another lens and find I didn't need to.

    I would really appreciate any help. Thanks!!
     
  2. MattKing

    MattKing Subscriber

    Messages:
    15,193
    Joined:
    Apr 24, 2005
    Location:
    BC, Canada
    Shooter:
    Multi Format
  3. Wendy Monahan

    Wendy Monahan Member

    Messages:
    5
    Joined:
    Nov 9, 2011
    Location:
    Las Vegas
    Shooter:
    Medium Format
    Thanks Matt for taking the time to reply. I can't seem to search anything on this site. I just get an error page.

    The link is really helpful!
     
  4. ctsundevil

    ctsundevil Member

    Messages:
    59
    Joined:
    Mar 31, 2008
    Location:
    Connecticut
    Shooter:
    Med. Format RF
    I use a D3 enlarger. It's very similar to the D4. To use a 135mm lens you will need a shorter lens cone. I measured the one I use for 135mm and it is 4" high. The 5 1/4" cone will only work with a 150mm lens.
    The 2 3/4" cone that you have is for a 105mm - I think.
    The focus track should say on it what kind of lens it is for. My 150mm track says that it is for a Rodenstock Rodagon. It works with other 150mm lens, but it works best with that particular lens.
    If you get yourself a 4" cone, you can use your 135mm lens with the 150mm track. It will work near the bottom of the track and once you raise it past the curve.
    The best thing to do is to get yourself a good 150mm lens since you already have the other parts.
     
  5. Wendy Monahan

    Wendy Monahan Member

    Messages:
    5
    Joined:
    Nov 9, 2011
    Location:
    Las Vegas
    Shooter:
    Medium Format
    Thanks for your reply. I was wondering if the shorter cone and 135mm focal length would work on the 150mm lens track. I don't recall what specific type of lens the track is for. Much of the information is difficult to read. I think I will take your advice and just get a good 150mm enlarging lens. Probably an easier fix than trying to track down the proper lens mount cone size. I have already spent several hours and uttered many foul words dealing with this specific issue!
     
  6. Wendy Monahan

    Wendy Monahan Member

    Messages:
    5
    Joined:
    Nov 9, 2011
    Location:
    Las Vegas
    Shooter:
    Medium Format
  7. ic-racer

    ic-racer Member

    Messages:
    7,193
    Joined:
    Feb 25, 2007
    Location:
    Midwest USA
    Shooter:
    Multi Format
    Lens Mounts

    421-150 Flat Mount for 50-60mm lenses (replaced by 421-170) DR
    421-151 1½" Cone for 75-80mm lenses (replaced by 421-188) DR
    421-152 2" Cone for 90mm lenses (replaced by 421-172) DR
    421-153 2½" Cone for 100/105mm lenses D
    421-154 4¼" Cone for 135mm lenses D
    421-155 5¼" Cone for 150mm lenses C
    421-156 5-5/8" Cone for 162mm lenses C
    421-028 Recessed mount for 28mm Componon D
    421-121 Recessed mount for 35mm Omegaron D
    421-122 Recessed mount for 25mm Omegaron D
    421-123 Mount for 60mm Componon
     
  8. ic-racer

    ic-racer Member

    Messages:
    7,193
    Joined:
    Feb 25, 2007
    Location:
    Midwest USA
    Shooter:
    Multi Format
    421-101 2 3/4" cone is not for your enlarger. Does it even fit?
     
  9. Wendy Monahan

    Wendy Monahan Member

    Messages:
    5
    Joined:
    Nov 9, 2011
    Location:
    Las Vegas
    Shooter:
    Medium Format
    Nope. The circumference is too large. I have a few other odd lens mounts as well. Everything was in the box I received upon purchase. I didn't realize that some were for another enlarger until I started dealing with the focusing problem. I hadn't intended on using them.