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  1. #11

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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?

  2. #12
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    Yes, the top bellows is completely collapsed. I have not called Beseler.

  3. #13
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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.

  4. #14

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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

  5. #15
    chuck94022's Avatar
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    Quote Originally Posted by Konical
    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
    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!

  6. #16

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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

  7. #17

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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

  8. #18

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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

  9. #19
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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

  10. #20

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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?

    Will

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