Beseler 45mxt full frame vignetting

Discussion in 'Enlarging' started by chuck94022, May 4, 2005.

  1. chuck94022

    chuck94022 Subscriber

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    I got frustrated with my Beseler 4x5 glassless negative carrier. It crops just a bit too much at the edge of my negative.

    I bought a couple of pieces of glass (from a framing store) and went about building a full frame (edge to edge) 4x5 carrier.

    My Beseler 45mxt has a Dichro 45s color head with a 4x5 mixing chamber.

    I was disappointed to discover that the 4x5 head and mixing chamber do not quite cover the negative edge to edge. There is a slight, intrusive vignette in each corner of the projected image. It actually intrudes slightly into the image. I guess now I know why the Beseler carrier crops as it does. It must crop right to the edge of this light circle.

    Has anyone else seen this with a Beseler?

    (While cooking up this plan, I was in the photo shop looking at a very nice Durst negative carrier, with built-in, moveable masks. But that negative carrier cost more than my entire enlarging system, so I decided to pass on upgrading! :smile: )
     
  2. Thomassauerwein

    Thomassauerwein Member

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    I use a 45mxt Have not had any vignetting for either 4x5 or 6x12. I do not use a color head however but can't see this as the source of your problem. unless the head is off center. The light circle is tight but I can get black borders, so there is some margin for error. Have you compressed the light bellows all the way?
     
  3. chuck94022

    chuck94022 Subscriber

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    I've attached an example. Yes, the bellows are fully compressed. I'm wondering if, for this type of print, I'll need to change my light source.

    The attached is a Tmax 4x5, printed on Ilford MGIV RC at grade 2. Note the corners.
     

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  4. chuck94022

    chuck94022 Subscriber

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    Here is an image using my Beseler 4x5 carrier. I focused inside the blades to show the natural edge of the carrier and the amount of crop relative to the edge to edge negative.

    (If you are using the Firefox browser, open each image in a new tab, then tab between them to see the differences.)
     

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  5. kwmullet

    kwmullet Member

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    The Beseler4x5 I have has an adjustable condenser and I have to crank that up or down to whatever format I'm in, 35mm, 6x6, 4x5, etc. Is there such an adjustment on yours?

    My enlarger is wrapped up at a previous house, but I'll be moving it in the next few days. If the mystery isn't resolved by then, I could shoot some quick digital pics of the adjustment I'm talking about & post them.

    -KwM-
     
  6. ann

    ann Subscriber

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    which lens are you using? 135 or 150.

    I have that enlarger, and use a filed out carrier at times, or a negatron, or glass carrier, and do not have an problems. However, i am using a 150.
     
  7. chuck94022

    chuck94022 Subscriber

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    KwM: Yes, it has an adjustment for various formats, and I have it adjusted for 4x5. In this setting the vignetting is minimized but not absent.

    Ann, good question. I'm using a 135. I have a 150, I'll try it.
     
  8. Claire Senft

    Claire Senft Member

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    Do you have a mixing box for a smaller format inserted? If you do this could be the cause of your problem.
     
  9. chuck94022

    chuck94022 Subscriber

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    Unfortunately, no, I checked that. It is definitely the 4x5 mixing chamber.
     
  10. chuck94022

    chuck94022 Subscriber

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    I just tried the 150mm lens. Same problem. It is definitely the light source clipping against the negative.

    For the moment I'll just have to live with cropped images in 4x5, and use this for 6x6 and 35mm only.

    Some day I might try a different light source, but in the mean time I'll just have to live with contact printing 4x5 if I want an edge to edge print.
     
  11. Claire Senft

    Claire Senft Member

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    I do not know if it makes a difference but have you used your top bellows, I assume raising it, to try to see if the coverage is improved? Have you called Beseler?
     
  12. chuck94022

    chuck94022 Subscriber

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    Yes, the top bellows is completely collapsed. I have not called Beseler.
     
  13. chuck94022

    chuck94022 Subscriber

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    Well, I probably should have done this to begin with. I pulled the head on the enlarger, and placed the negative against the bottom of the mixer. The diameter of the mixer chamber is smaller than the diagonal of the film. Therefore, the vignetting. It is physically impossible to avoid.

    Now a question for those of you with different heads on your beseler 45mxt or equivalent. If you place a 4x5 negative against the bottom of the head (where the light comes out), does the negative fit completely inside the light source, or does it overlap the edges? (I'm trying to determine if it is worth buying, for example, a condenser head for my enlarger to do these kinds of enlarged, edge to edge prints.
     
  14. Konical

    Konical Subscriber

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    Good Morning, Chuck,

    I use a Beseler MCR-X with the condenser head. When positioned for 4 x 5 film (according to the scale), the bottom of the condenser lens is quite near the negative; in fact, I make sure that it is very clean, because a dust spot on the bottom of the condenser may sometimes come almost into focus on the print and be visible. I cheat a little by positioning the condensers slightly higher than the 4 x 5 mark on the scale, maybe one-eigth to one-quarter of an inch. I still get enough coverage in most cases. Just because of this potential problem, I generally compose a little "loose" so that I don't have to worry about the extreme corners on the negative.

    Konical
     
  15. chuck94022

    chuck94022 Subscriber

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    Hi Konical, thanks for the reply.

    If you were to do as I did, and try to enlarge the edge-to-edge negative, would you get sufficiently broad light from the condenser to cover the whole negative, edge to edge? My diffuser light is also very close at 4x5 settings, but the diameter of the diffuser is not sufficient to fully light the entire negative.

    What I'd like to find out is whether the condenser has a larger illuminated circle than my diffuser chamber, so that the negative would be lit all the way to the corners. If so, I might pick up one in order to do this kind of print.

    It would be great if you could check it out with your enlarger. If you have a sheet if glass (an 8x8 square fits perfectly in the beseler), just center a negative on top of it in the negative carrier slot, focus the enlarger and see if you can project the negative all the way to the edges, without vignetting as seen in my example picture. Could you give that a try?

    Thanks!
     
  16. Konical

    Konical Subscriber

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    Good Afternoon, Chuck,

    I haven't really experienced any vignetting, even with the condensers located around 1/4 inch above the 4 x 5 mark on the scale. As I indicated above, I normally use that slightly higher placement to keep any dust speck on the condenser lens from showing up as a blurry lighter spot on prints. Coverage and evenness of light just hasn't been an issue with my MCR-X as long as the appropriate lens is used to fit the format. I'm sorry that I have no idea of what is causing your problems.

    Konical
     
  17. Konical

    Konical Subscriber

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    Good Afternoon Again, Chuck,

    I just went back and looked at your two photos. That's a fairly extreme problem, which, as I indicated just above, I've never encountered. Also, I just checked and found, not surprisingly, that the light circle I get is a little over 6 inches with the condensers just above the marked 4 x 5 position. I still try to shoot without extremely tight composing, but corner to corner illumination coverage for the 4 x 5 carrier isn't a factor.

    Konical
     
  18. wilhelm

    wilhelm Member

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    I'm running into a very similar problem with my 45MX right now. I've got an Aristo D2 cold light head, and am using a Schneider Componon-S 135mm lens, and am seeing some vignetting, just about the same as Chuck's example pic. The upper bellows are fully compressed. I took the head off and compared the lighted area of the head to the size of the negative, and there's more than enough area for the negative to be completely illuminated. So it seems like the lens is the culprit. Schneider's site lists both the 135mm and the 150mm Componon-S lenses as covering 9x12 (15cm diagonal), not 4x5 (16.2cm diagonal). Anybody done any coverage comparisons between 135s and 150s for enlarging 4x5?

    Will
     
  19. Jim Noel

    Jim Noel Member

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    I use a Beseler MCRX and have both a condenser and a VC-CLS light source. The VC-CLS head is the only one of several variable contrast heads which I tried which has a surface larger than the cross section of a 4x5 negative.
    WIth either of these heads, and a 150 Rodagon lens, the upper bellows completely collapsed, I have never seen any sign of vignetting, even if I choose toprint with the lens wide open. When I used a 135 Componon, although there was no hard edge, there was significant light fall off in the corners.
    I don't know how this will help you, but it is my experience.
    Jim
     
  20. wilhelm

    wilhelm Member

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    Thanks for responding, Jim. You've semi-confirmed what I was thinking, that the 135mm just doesn't have quite enough coverage to do the job. At your comment about using the 150mm wide open, I tried stopping WAY down to see if the vignetting goes away. It doesn't seem to. And print exposure times at those apertures would become far too long to be useful anyway.

    Sounds like it might be worth trying a 150mm lens, to see if that fixes my problem. Anybody got one they'll let go cheap? :smile:

    Will
     
  21. pandino

    pandino Member

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    Chuck,
    Are you sure you have the negative centered in the negative stage? From the scan, it appears off center. When using the negative holder, the locator pins will assure that the negative is in the center of the projected area.

    I'm not sure how you'd center with your homemade glass holder other than checking visually.
     
  22. Pragmatist

    Pragmatist Member

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    Chuck, this seems to be as much a product of the carrier as the lens. On mine (with the square bottom bellows) the negatrans tends to vignette on the right top and bottom when there is not enough clearance to the top, and on the bottom with the glass carrier. Not much, but this is where it will first show up with a 135mm Nikkor. No problems at all with the 150mm. Optically, the negative is centered.

    There is only a slight difference between the condensor and diffuser head diameters (6 3/8 versus 6 1/4" respectively) The thickness of the carrier can play a role also. If you are working toward full-frame, I might suggest trying an 150mm and seeing if that solves your issue.
     
  23. Frank F

    Frank F Member

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    There were a couple of designs for the Schneider and Rodenstock 135 lenses. I remember that one of the designs was older and did not cover as the more modern design. I have the most modern 135 Componon-S, and it cover the 4x5 neg just fine. ( It is used on a Saunders 4500 enlarger.).

    Maybe you should post what the 135 looks like, and maybe someone can tell you if it is an oldie... like a chorme lens rather than the more modern all black lenses....