A question for owners of 4x5 enlargers

Discussion in 'Darkroom Equipment' started by Steve Smith, Feb 29, 2008.

  1. Steve Smith

    Steve Smith Subscriber

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    For a while now I have been thinking about building a 4x5 enlarger.

    To save a lot of trial and error and perhaps some complex calculations, I would appreciate it if someone could help me out by measuring the distance from the negative to the lens board at both minimum and maximum bellows extension on a standard 4x5 enlarger.

    Thanks.



    Steve.
     
  2. bdial

    bdial Subscriber

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    Omega DII
    max 9.5 (243), min 4.25 (108), Including depth of lens cone which is 2.5 (64)

    LPL 4500
    Min 2.5 (64), max 9.5 (243) , including depth of the lensboard which is .75 (20)

    Measurements are inches and (mm), and are made from the negative stage to the lens mount surface.
     
  3. Steve Smith

    Steve Smith Subscriber

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    Thanks. That's exactly what I wanted.


    Steve.
     
  4. Bob F.

    Bob F. Member

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    Durst L1200. Min 40mm, max 240mm; negative to lens panel (give or take a couple of mm). I seem to get away without a recessed panel with a 50mm lens for 135, but others have found them necessary.

    Have fun! Bob.
     
  5. Chan Tran

    Chan Tran Member

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    I found that with my Beseler 45 the minimum distance is a bit too long for 35mm format. I have to get the bellow to compress quite tight to focus correctly with most magnification.
     
  6. Mark_S

    Mark_S Member

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    Steve, I am at work now, so I can't measure my two Beseler 45s (one with the Ilford MG600 head, one with the Condenser Head), but an observation:

    When I use the one with the Ilford MG600 head, with 35mm, I am often at minimum extension - so much so that I have considered making a recessed lensboard for my 50mm lens. I rarely find that I need to use the maximum bellows extension, since I rarely print really small, and when I do, it is usually not with 4x5 negs, so I can always get a smaller image with a more convenient enlarger head height by using a longer lens.

    You can calculate the maximum bellows extension required too, if the distance between the negative and the optical center of the lens is B, and the distance between the center of the lens and the easel is E, then the magnification is E/B and if the focal length of your lens is F, then when in focus, 1/B + 1/E = 1/F all of which means that if the smallest print you want to make is a 1:1 size print, then the maximum bellows extension is approx 2X the lens focal length. The shortest bellows extension would come about with an infinite sized print, at which point the bellows extension is equal to the lens focal length.
     
  7. Jim Jones

    Jim Jones Subscriber

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    On my old 4x5 DeJur the minimum is about 3.5 inches and the maximum about 9.1 inches. That long minimum means a lens board recessed 1.6 inch and a 3.5 spacer above the film to focus the condenser are required for 50mm lenses.
     
  8. r-brian

    r-brian Member

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    The focal length of the lens is going to make a difference in the distance. In bdail's post, I'm assuming the measured distance for the DII is for a 135mm lens, based on the 2.5 inch cone. A 150mm lens takes the 4 inch cone.
     
  9. dpurdy

    dpurdy Subscriber

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    Interesting. I use a Beseler 45 mxt and I have no problem focusing with a 50mm lens even at the largest enlargement. Mine is a grey one from the 60s. Perhaps they tried to cut some corners in the later models.
     
  10. Nick Zentena

    Nick Zentena Member

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    Might depend on which 50mm you are using. Some will have different flange focal distances. My CB-7 is pretty tight with the Nikon 2.8. My memory tells me other brands would need more space so would have no problem. Beseler sells [or used to] a recessed board and I think it was specced for the Nikon 50mm F2.8.
     
  11. Steve Smith

    Steve Smith Subscriber

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    Thanks for the information everybody.

    I already have an LPL 6700 enlarger for everything up to 6x7 so any problems with a 50mm lens on 35mm film don't really matter. I will build this enlarger just for 4x5 (or 5x4 as we call it over here - no idea why it's different!). I will then make negative holders for 6x9, and 6x12 as well.

    Initially I will use a diffused light source and include a tray for contrast filters but I may play around with blue and green LEDs as well.

    I have done some initial tests using a negative taped to a small Jessops 5"x4" light box and a 105mm lens and it seems promising. Somewhere I have a Wray 4 1/2" enlarging lens but I cant find it at the moment. The 105mm lens seems to show all of the negative though so will probably be fine for my initial tests.

    I have the bellows and focussing rack from a long deceased 9x12cm camera so all I need to work out now is a base, column and some way of moving the enlarger head up and down the column. I am thinking of using a square section with register pins with holes every 1/2" or so. Not as convenient as a wind up and down mechanism but should be useable, especially if it is only used for 4x5 on standard paper sizes.


    Steve.
     
  12. dpurdy

    dpurdy Subscriber

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    I have an 8x10 enlarger that I made from a broken wooden 8x10 field camera. Since I almost always print full neg I decided to keep the camera part solid and made shelves at the exact right height to give me 11x14 or 16x20 with border and 16x20 full bleed. The only thing that moves on the enlarger/camera is the focus. For the negative holder I use two pieces of glass that fit exactly into the camera back after removing the part with the ground glass. It all works suprisingly well. I had a good day with the table saw I guess. I made it from wood including the light head which is a box holding 6 soft decorative light bulbs above a sheet of transluscent plastic for diffusion. The only problem is the size of the thing which requires I get down on my knees to focus.
     
  13. dpurdy

    dpurdy Subscriber

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    Oh I got so carried away bragging about my 8x10 enlarger I forgot to make the point that I found the bellows to be a pain in the rear and ended up removing them and replacing them with plain black cloth that had no tendency to affect the alignment.
     
  14. DannL

    DannL Member

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    Put a 4x5 camera on a tripod, pointing down. Configure/design a frame to hold the negative. Insert it in the camera and backlight the negative. It's a simple enlarger. (with movements)
     
  15. Steve Smith

    Steve Smith Subscriber

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    That is quite a good option as I'm also currently building another 4x5 camera too. The old one does not fold up and is a bit bulky which would make it an ideal candidate for an enlarger conversion.


    Steve.
     
  16. DannL

    DannL Member

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    In all actuality you can eliminate the tripod. Early enlargers were also on the horizontal. You can make a horizontal rail. As long as you can keep the paper secured on the vertical.
     
  17. DannL

    DannL Member

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