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  1. #1
    noblebeast's Avatar
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    This will be a somewhat windy explanation with a couple of questions at the end. I have been having problems with edge to edge sharpness in my prints and after following the good advice in other threads regarding enlarger alignment, I brought my Beseler 23C up to code, so to speak. But I still can't get the negatives focused all the way around: the center will be sharp but the left side will be slightly out of focus and the right side a bit more. I did battle with it tonight for about two hours using a bit of film leader with a grid scratched into it, and no amount of adjusting will get all quadrants into focus - the center still gets very sharp, but even when I get the edges close they still don't get as sharp as the center. I've tried shifting the lensboard to see if the soft areas change, but they stay constant. Again, I've already checked to make sure the different planes are parallel.

    I use 35mm and 6X4.5 and 6X6 formats, and have verified that the negatives I have been trying to print are indeed sharp from edge to edge.

    So I've come up with two possible solutions I wanted to get advice on, and please feel free to offer more. Number 1: my lenses are probably entry-level, hobbyist quality. Would higher quality enlarger optics make a substantial, easy to see difference in the edge to edge sharpness? Number 2: I'm using the basic negative holders. Would glass holders (assuming they make them for the 23C) make a noticeable difference by virtue of the fact that they hold the negatives flatter?

    Thanks in advance.
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  2. #2
    clogz's Avatar
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    Yes, I prefer using glass neg. carriers esp for MF negatives. Make sure though that the top one is of the anti-newton variety.
    Digital is best taken with a grain of silver.

  3. #3

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    nabblbeast, if u use condensor head, than problems is more pronounced. the reason is that very quekly the negative is hot from the light sourse and it changes the form. so what u do is that u focus on the centere which is not on the same plane as other parts. anti-newton helps very much, but be aware of dust etc. u have to be even cleaner than befor.
    align the enlarger of course. and yes, better lenses helps. but only when u have made the besic things -alighned enlarger and flat negative.
    also, if u print with the filters, wether the normal head(deffused) or with the condensor or the cold (with filters), make sure to change filters very gently, and wait abit, couse the vibration makes problems.
    victor

  4. #4
    dr bob's Avatar
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    As previously stated, negative "pop" is a possible problem which will be corrected by using glass carriers. Have you tried stopping down to the maximum to compare prints? A smaller diaphragm (exception being a point source head) should minimize focus (sharpness) problems stated.

    Personally, (dangerous territory, I know) I found my enlarging problems dissipated greatly when I first invested in a "good" lens to replace the "entry-level, hobbyist quality" ones which came standard on my first enlarger - including overall sharpness. BTW, if you are doing b&w, the super modern, highly corrected $$$ lenses are not really required.
    I love the smell of fixer in the morning. It smells like...creativity!
    Truly, dr bob.

  5. #5
    Ed Sukach's Avatar
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    Quote Originally Posted by noblebeast
    But I still can't get the negatives focused all the way around: the center will be sharp but the left side will be slightly out of focus and the right side a bit more.
    ... no amount of adjusting will get all quadrants into focus - the center still gets very sharp, but even when I get the edges close they still don't get as sharp as the center.
    ... Number 1: my lenses are probably entry-level, hobbyist quality. Would higher quality enlarger optics make a substantial, easy to see difference in the edge to edge sharpness?
    It sounds like the lens itself. What aperture are you using? I usually focus wide open to minimize depth of focus, and print closed down to use the benefit of depth of focus. Try an aperture near the middle of the scale.
    An additional consideration is the ratio of enlargement. Inexpensive lenses are designed to work best at relative small ratios with the idea that beginners will not need LARGE prints. The effects of field curvature (which your descripption sounds like) are more noticeable at higher ratios.

    Will the use of a "high quality lens" make a substantial difference? At high magnification ratios, it is likely. Will it be immediately discernable? Nearly impossible to answer .. It depends on the subject, the print size, viewing distance, whether or not smoking is allowed in the gallery, level of alcohol consumption....

    Be careful of one optical characteristic - color correction. It is as necessary for sharpness (resolution) in black and white images as it is with those printed in color. Different wavelengths of light (colors) should, ideally, focus to the same place; if they do not, there will be a "rainbow" effect at the image edges - usually most noticeable at the extremes of the field. The color *fidelity* - the accurate rendering of colors, is a different animal.
    Carpe erratum!!

    Ed Sukach, FFP.

  6. #6

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    Couple more thoughts on this problem, and I assume it is the condensor variety.

    The condenser setting needs to be changed for the different negative sizes. The condenser head needs to be move up from the negative stage when using 35mm and moved closer to the negative stage when using larger formats. You should have an adjustment bar on the right hand side of the enlarger.

    Next are you using the same lens for all your formats. A lens that covers 35mm will not give good coverage with a 6x6 negative, you should ideally be using something like this:

    35mm negative = 50mm enlarging lend
    6x4.5mm negative = 75mm - 80mm enlarging lens
    6x6cm = 80mm enlarging lens

    You could of course use an 80mm enlarging lens for all formats but you will be limited wth the magnification you can get when you use an 80mm lens with a 35mm negative.

    I would check these out first before purchasing a new lens.

    - Mike

  7. #7
    ann
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    it would appear others have covered the most common problems. Have you check the baseboard to be sure it is level? We had a board that looked flat, etc. but when we continued to have trouble with sharpness i got out the leveler and started checking. it was not flat, very little but never the less not flat. Just another option in the puzzle.

  8. #8
    Les McLean's Avatar
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    I experienced the same problems a few years ago and I was using good enlarging lens on a Zone VI VC Cold Cathode enlarger and thought that I had my enlarger correctly aligned. I tried every remedy mentioned here but it was not until I invested in a quality lens alignment system, the Versilab Laser tool, that I cured the problem.

    It takes less than 2 minutes to check the alignment and it is sharp from corner to corner every time. I have also noticed that the alignment can shift as the head is moved up and down the column so for that reason I check the alignment for every print that I make if I have moved the head on the column. The initial investment for the tool may seem to be high but in my view if you are looking for the best results you should be prepared to spend the money, I believe there is no other way.

  9. #9
    noblebeast's Avatar
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    Wow! First of all a Big THANK YOU for all of the quick and informed replies - that's what makes APUG the best place in the whole wide world!

    To answer some of the loose ends: Yes it is a condenser enlarger and yes I adjust the condensers for each film format.

    I have been getting the problem regardless of how far down I stop the lenses. I used to use the smallest aperture but then read that diffraction can occur at the smallest lens opening on the enlarger as well as the camera so last night I tried stopping down to the middle stops - still no edge sharpness (fuzziness no better, but no worse).

    I use a 50mm lens for 35mm and a 75mm for medium formats. Again, the quality of these particular lenses is very suspect - for example the 50mm only has four, count 'm 4, aperture blades! I have only been enlarging to 8X10, printing the negs as full frame as the different ratios will allow.

    Les seems to have the ultimate alignment solution, but since, to partially quote Paul Simon, "I am just a poor boy..." (and in fact I was once a boxer), I am leaning towards better enlarger optics since they won't really go to waste anyway. Based on the responses thus far that seems like the next step.

    Thanks again, you're all the best!

    Joe
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  10. #10
    Ed Sukach's Avatar
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    Quote Originally Posted by noblebeast
    I used to use the smallest aperture but then read that diffraction can occur at the smallest lens opening on the enlarger as well as the camera..
    I wouldn't hesitate to use the smallest f/stop because of the "risk of diffraction."
    Any lens designer worth half the powder to blow them to hell will know enough to limit the smallest lens opening available so that diffraction errors will not be a problem. Diffraction is independent of the glass itself: it is a result of the physical size of the lens opening and the distance of aperture to film plane.
    That is why short-focus lenses have smallest openings of f/16 and the long, large format lenses go to f/64 or ?

    Of course, it is possible to find a lens that is a total disaster.

    The more I think of it, the more inclined I am to agree with Les... It does sound like an alignment problem. Is there a uniform loss of sharpness around the periphery of the frame? If the image is sharp along a particular radial axis when the center of the image is in focus, the baseboard is not perpendicular to the optical axis of the lens.
    Carpe erratum!!

    Ed Sukach, FFP.

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