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  1. #1
    Worker 11811's Avatar
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    Beseler 23C - Focus not flat

    Have an old Beseler 23C. The old, "Universal Color" type.

    I can not get the thing to focus evenly across the easel.

    If I focus at the center of the image, the edges are out of focus. Mostly at the top, left and the bottom right.

    If I focus at the top, left, the center can be brought into focus but the bottom right will be out and vice versa.

    I can fiddle and fiddle with the focus but, eventually, I can get it to be close but not perfect.

    I have aligned the X-axis pretty well. If I fiddle with it, I can get the left and right sides to focus pretty darned close to the same point.

    I can't figure out if there is a Y-axis adjustment.

    I have tried putting several pieces of photographic paper between the negative holder and the bottom of the stage. If I put 6 or 8 slips of paper in there I can get the thing to focus pretty close to flat. But putting that much shim material in the trap every time I want to make a print will be a PITA in short order.

    Does my lens have some kind of astigmatism problem? Is there some way to ensure alignment of the lens on the lens board? Is there an adjustment of the front-to-back alignment that I'm not able to find?

    I have heard that this vintage of Beseler can be cranky in the focus department. Is this just something I'm going to have to live with?
    Randy S.

    In girum imus nocte et consumimur igni.

    -----

    http://www.flickr.com/photos/randystankey/

  2. #2

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    Hi,

    The negative stage must be aligned with the easel. Assuming your easel is completely level (which it should be, if it is not a battered speed easel or a bladed easel with missing feet), you can use the baseboard as well.

    I don't know enough about that particular enlarger to tell you where the alignment hardware is...but I am almost certain that it must be there. Even my cheesy Omega B22 was align-able two ways (and believe me, I had to align it OFTEN), and the Beseler is a better enlarger in many ways.

    I am 99.9 percent certain it is not your lens.

    The big thing that will throw Beseler enlargers severely out of alignment is if the left and right gears end up at different points on the left and right columns; a "jumped" tooth on one of the two column racks. Omegas, Dursts, DeVeres, etc. do not have this problem, as they use only one column. However, you already have achieved alignment in this axis, so I think you are OK. It would also be very easy to see this with the naked eye if it was happening.

    As I said, I do not know the 23 models well, but the 45 models have a lens stage tilt, which is actually a great feature to have. I have used this feature quite a bit when shooting with cameras that have no movement or limited movement (such as my Speed Graphic, which has tilt, but no swing). It is possible that if the 23 has this feature, the lens stage is not level to the film stage. Again, this would be along the axis you have already successfully aligned, but you definitely want to look at it.

    What you need is the instruction and/or service manual, which I am sure you can get either second hand or from Beseler proper.

    Good luck. It is a pain, but entirely worth the effort, so stick with it until you get it right.
    2F/2F

    "Truth and love are my law and worship. Form and conscience are my manifestation and guide. Nature and peace are my shelter and companions. Order is my attitude. Beauty and perfection are my attack."

    - Rob Tyner (1944 - 1991)

  3. #3
    Vaughn's Avatar
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    Unless the earlier models are different, there are two axis of adjustments, both below the lens stage. One that allows the lens to swing left and right, and the other is a screw and nut that adjusts how far the head tilts toward the column.
    At least with LF landscape, a bad day of photography can still be a good day of exercise.

  4. #4
    Worker 11811's Avatar
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    I only have to turn the focus knob a little bit to get the focus to change.

    The entire distance the carriage moves up and down the focus rails is less than a 1/32 of an inch. I put the top/left in focus and marked a pencil line on the rail then focused the bottom/left and marked another line. Both pencil lines touch. The distance to focus one part of the image vs. the other is about the width of a pencil line. (Freshly sharpened.)

    Vaughn, are you talking about that "bumper stop" underneath the back of the carriage? I messed with that but it didn't seem to make much of a change. I'll have to look into it some more.

    Maybe I should move the head up to make an 11x14 blow-up and align that. Theory being that, if that size is in alignment, the smaller sizes should be a piece of cake. Right?

    Here are some test prints I made with SMPTE test film I brought home from work.



    (Full Size)
    http://homepage.mac.com/randystankey...B23C/RP-40.jpg



    (Full Size)
    http://homepage.mac.com/randystankey...B23C/Clips.jpg

    Yeah... I've got OCD about focus.
    It's an occupational hazard. When you have 200 paying customers screaming because their movie isn't in focus, you tend to get a bit jumpy about it.
    Randy S.

    In girum imus nocte et consumimur igni.

    -----

    http://www.flickr.com/photos/randystankey/

  5. #5

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    I use to be perplexed about why the lens does not have an adjustment independent of the rest of the head to adjust it from front to back. What I do now to align the lens from front to back is to loosen the screws on one of the two plates that hold the lensboard. This allows the lens to be adjusted either higher in the back or front depending on what pair of screws you adjust. Made all the difference in the world to me.

  6. #6
    Worker 11811's Avatar
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    I think I've found the source of the problem.

    Reasoning from this point: "The center line of the lens must be perfectly perpendicular so that the focal plane of the lens is perfectly parallel to the film plane."

    Investigation of the lens board and the way it aligns, I found some slop in the screws that hold it in place and allow the user to align the X-axis. If those parts and screws are not aligned and tightened properly, misalignment can occur.

    This is what I found:
    [YOUTUBE]http://www.youtube.com/watch?v=WqT_XfK2G-c[/YOUTUBE]

    I figure if I put a piece of thin, metal shim stock in there and tighten things up the way they should, I'll be able to line this baby right up!
    Randy S.

    In girum imus nocte et consumimur igni.

    -----

    http://www.flickr.com/photos/randystankey/

  7. #7
    dances_w_clouds's Avatar
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    There is adjustable lens boards for the Beseler that may help the adjustment for your lens

  8. #8
    Vaughn's Avatar
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    Quote Originally Posted by Worker 11811 View Post
    Vaughn, are you talking about that "bumper stop" underneath the back of the carriage? I messed with that but it didn't seem to make much of a change. I'll have to look into it some more.
    The bumper is used to make alignment adjustments (or at least I do on the 8 23C's that we have). A noticeable change occurs when I am using the laser alignment tool I have. But I will also be checking those screws when I align all of them before classes start in the Fall!

    Vaughn
    At least with LF landscape, a bad day of photography can still be a good day of exercise.

  9. #9
    Worker 11811's Avatar
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    I wish I had the laser thingamajig! I've got to do it with a spirit level, some test film and my eyeballs.
    Randy S.

    In girum imus nocte et consumimur igni.

    -----

    http://www.flickr.com/photos/randystankey/

  10. #10
    Vaughn's Avatar
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    I just use the laser to get it as close as I can, then use a test negative (scratched in a test pattern) to do the final adjustment. It is the light that hits the baseboard that matters!
    At least with LF landscape, a bad day of photography can still be a good day of exercise.

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