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  1. #1

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    Enlarger alignment - what is "good enough?"

    I have been trying to align my newly refurbished Omega D-2. I recently was able to borrow an alignment tool made by Bessler and am using it with D-2.

    Alignment itself was not a problem. Baseboard to lens stage to film stage. All fairly well aligned all within about 1/5th of a bubble. But, the problem is repeat-ability!

    If I align it at one height, move the lamp assembly up and down, focus knob right and left, and re-measure, I read differently. Do it again, and it is yet, again, different. Everything is/was tight and there are no obvious "slops."

    I soon realized, expecting this machine to align and repeat with precision of a highly calibrated scientific instrument is, probably not realistic. Not only is this equipment over 50 years old, is simply isn't made with that kind of precision.

    So the question - at what point, is it good enough? For a point of reference, I do not expect myself enlarging to any bigger than 10x14 using 35mm or MF negs. I do crop some times and my lens is NOT an APO type.
    Last edited by tkamiya; 07-20-2010 at 11:28 AM. Click to view previous post history.
    Develop, stop, fix.... wait.... where's my film?

  2. #2

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    getting lens perpendicular to neg stage is critical. Then getting easel perpendicular to lens is easy to do with a grain magnifier. Start at top of system and work down. Not from bottom up because if lens and neg aren't right then setting easel will be wrong.

  3. #3

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    Can't do that because of inter-dependency of adjustments. The question still remains - what's good enough?
    Develop, stop, fix.... wait.... where's my film?

  4. #4
    Bob Carnie's Avatar
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    Putting the top of the column braced to the wall will help by keeping the top stable.
    This should help keeping the top to bottom alignment.

    Whats good enough? depends upon you and how edge to edge critical you will accept with your work.

  5. #5
    Mike Wilde's Avatar
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    A thumbnail alignment tool -that I use for checking from time to time that important things are still working and in alignment.

    DIY - take a black film leader of the format in question, and put it in the neg carrier with the emulsion side up. Scratch the outline of the neg carrier with a pin/needle. Take the neg out, and draw diagonals from corner to corner.

    Put the film back into the carrier, and mount the carrier in the easel. Focus on the neg at the desired head height under test, with the lens cone, lens etc. under consideration. The diagonal lines should be sharp from end to end, and the distances of the opposing sides should measure the same.
    my real name, imagine that.

  6. #6

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    You can always stop down the enlarger lens more. This gives you some slack in the system at the expense of possibly hitting diffraction limits.

  7. #7

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    Quote Originally Posted by tkamiya View Post
    Can't do that because of inter-dependency of adjustments. The question still remains - what's good enough?
    Well you have to un-inter-dependancy them.

    Lens mounts/board can always be shimmed with silver foil so it is always possible to align them and they will stay put unless you move them.
    Depth of field at the negative is very narrow so needs to be spot on. Even a small tilt of lens off axis can make a big difference on the paper edge.
    Last edited by tlitody; 07-20-2010 at 04:40 PM. Click to view previous post history. Reason: I meant depth of field not depth of focus

  8. #8
    Steve Smith's Avatar
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    Quote Originally Posted by tlitody View Post
    Well you have to un-inter-dependancy them.
    Indeed. Have a good look at what affects what to determine the correct order of setting things up. There will always be a way of doing it and if it's a factory produced enlarger it will be a simple process. If the lens alignment goes out just by moving the lens stage up and down then there is a problem somewhere else.

    Quote Originally Posted by tlitody View Post
    Depth of focus at the negative is very narrow so needs to be spot on.
    Aligning the lens to the negative carrier is the first thing I would look at. Once you have got this right, the baseboard alignment will probably be fine. If the baseboard was out enough to make much of a difference you would probably be able to tell just by looking rather than needing any fancy measuring tools.


    Steve.

  9. #9

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    Quote Originally Posted by tkamiya View Post

    I soon realized, expecting this machine to align and repeat with precision of a highly calibrated scientific instrument is, probably not realistic. Not only is this equipment over 50 years old, is simply isn't made with that kind of precision.

    So the question - at what point, is it good enough? For a point of reference, I do not expect myself enlarging to any bigger than 10x14 using 35mm or MF negs. I do crop some times and my lens is NOT an APO type.
    I have the same problem with my enlarger, an Omega B66. My father bought it new in 1970 and always took fanatic care of it. Now I use it so I know it is in perfect condition, but even still, when I measure alignment with a very precise tool (digital inclinometer precise accurate to +/- 0.1 degrees), it's difficult to ever get the same reading twice. Just changing the hight or touching the damn thing can cause variations of .2 degrees. Unless you have some monster large format enlarger braced to a concrete wall etc, I doubt alignment any more consistent than this is realistically achievable. Even if you can get it perfect, the next time you slide the negative holder in, or focus, it will probably change your measurement slightly. Since I can't afford a nice new Saunders 4500 or anything like that, I have no choice but to do my best with what I have. As long as I stop my lens down 2-3 stops, I find these very small variations insignificant when I check grain focus. Negative buckling is another story as how flat your negative is will affect focus/sharpness much quicker.

  10. #10
    Ian Grant's Avatar
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    Quote Originally Posted by Bob Carnie View Post
    Putting the top of the column braced to the wall will help by keeping the top stable.
    This should help keeping the top to bottom alignment.

    Whats good enough? depends upon you and how edge to edge critical you will accept with your work.
    And then throwing the spanner in the works - you need a bit of tilt to correct verticals so raise the front of the paper easel up an inch

    With a good lens stopped down a couple of stops it's critically sharp again, corner to corner.

    Alignment's important but good lenses more so.

    Ian

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