Help with enlarger light distribution

Discussion in 'Enlarging' started by digiconvert, Oct 28, 2006.

  1. digiconvert

    digiconvert Member

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    Some replies to my post on the selenium intensified neg have suggested that I have a 'cold spot' in the corners of my enlarger. I have looked at this and find something akin to vignetting on the top corners (see attached-phonecams do have a use !) I use an 80mm lens (Nikor) so do not believe this to be a problem and have taken the condensor out, cleaned it, tried it upside down etc. to see if something is amis but no improvement. Given that the Axomat is a very simple enlarger the only other possibility is the bulb which is in it. It's probably a small globe household bulb.
    Any ideas PLEASE ?
     

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  2. bill schwab

    bill schwab Advertiser Advertiser

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    Ah... just as I thought. Is this projected through your negative carrier? Is there a way to adjust the condenser Chris?

    B.
     
  3. digiconvert

    digiconvert Member

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    Yes through the carrier (It's the same without). As far as I can tell the condensor is just one big lens (about 2" deep in a steel case) I thought perhaps one way up for 35mm one way for 120 but that didn't work-I have also tried a different condensor from a beat up Axomat from college , same result.

    Maybe I'm going to have to live with this until my printing is good enough to persuade my dearest that a nice s/h De Vere is really more important than a new stair carpet :sad:

    Cheers for any advice - and your time.
     
  4. JBrunner

    JBrunner Moderator Staff Member Moderator

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    Is it vignetting in the other two corners as well? If it is not, you may be able to find a way to move the lens/enlarger center in relation to the baseboard.
     
  5. Jerevan

    Jerevan Subscriber

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    Could be the bulb itself. Get one that's made for enlargers. There are two different kinds, depending on how the bulb is placed in the enlarger (vertical or horisontal). The light is directed in different ways depending on how it sits. And check to get the right wattage, too. Sometimes the bulb socket can be shifted (my Durst works that way) so it is centered.
     
  6. Ole

    Ole Moderator Staff Member Moderator

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    It could be the bulb... If the bulb is in the wrong position and/or the wrong size, this is exactly what you would get. I've tested a lot of bulbs to find a viable alternative in my L138S - no success so far. But I do have one bulv which I'm keeping for negatives shot with far too wide lenses with lots and lots of light falloff...
     
  7. JBrunner

    JBrunner Moderator Staff Member Moderator

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    I would defer my advice to Ole's. I believe his advice is more on target.
     
  8. digiconvert

    digiconvert Member

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    I've tried every way to get the head to move relative to the bulb and v/v but no luck so I suspect a new bulb is my next step- shame I'd got the sob story all ready "and I may as well get an enlarger that will do 4 x 5 in case I get into that" followed by "Now I've got a 4x5 enlarger I may as well get an LF camera dear"

    Mind you the bulb is probably cheaper.

    Thanks to all who have replied, this really is a fantastic place :D

    Cheers CJB
     
  9. Mike Kennedy

    Mike Kennedy Member

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    I did a quick check on-line and found the previous posts might have nailed down your problem.
    Your problem could lay in a misaligned condenser or lamp.And make sure you have the correct bulb for your specific enlarger.

    Mike
     
  10. digiconvert

    digiconvert Member

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    Anyone know the right lamp for a Meopta Opemus 5A ? No luck so far in my searches.
     
  11. JBrunner

    JBrunner Moderator Staff Member Moderator

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  12. Ole

    Ole Moderator Staff Member Moderator

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    It sould have a 150W bulb with 75mm diameter, I believe. Same as my Opemus 6, if I were to use it with condensers (I don't, I have a colour head and itr's great).
     
    Last edited by a moderator: Oct 28, 2006
  13. MattKing

    MattKing Subscriber

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  14. digiconvert

    digiconvert Member

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    Thanks a lot, I had found the czek version and I don't read that too well !!!!

    And Ole, Most people cn mkea out poor spelling - stick with the wine , you know it makes sense :smile:
     
  15. Donald Miller

    Donald Miller Member

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    The lamp that you need if you had 115 volt power, is a PH 212. It is a 150 watt enlarger lamp and is sold by the Bulbman.com and BandH Photo.com I don't know about your voltage though. I imagine that you are at 230 volt service.

    I think that the correct bulb will make a big difference.

    I had to design a retrofit involving a reflector for my Durst 138S
    when I went to a 1000 watt lamp...so bulb (hence physical size of the light source) makes a big difference.
     
  16. JBrunner

    JBrunner Moderator Staff Member Moderator

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    A thousand watts? Was Terry Mester telling the truth??
     
  17. Donald Miller

    Donald Miller Member

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    Yep, that is what I have in there now. It doubles as a tanning light while I print. Provides heat in the three days of winter that we have here. It's a little on the fast side. LOL
     
  18. canonman

    canonman Member

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    Hey,
    you need an opal- bulb 150W for the Opemus.
    Good luck - Frank