Enlarger alignment and grain focusing

[Photopathe]

Hi! I have a Beseler 45MX and a Versalab Parallel alignment tool which has been calibrated very recently by the manufacturer. Apparently I successfully aligned the negative stage by sandwiching the alignment glass in the negative carrier. I then aligned the lens by attaching the glass in front of then. So far so good, but then if I try to focus on the grain across the whole image on the lens board it doesn't work. I focus on the central part and then move the grain focuser close to the edge of the image and I need to adjust focus as I don't see the grain there. Going back to the central part, no surprise, focus is off. What could be wrong? I'm puzzled.

 

[Pieter12]

Lens.

 

[wiltw]

What enlarging lens?
The lens needs to be 'flat field' corrected, or else it might have curvature of field. In a camera lens, an improperly designed lens the plane of focus is not truly a plane, but a curved field!

 

[Photopathe]

Thanks for the replies! Componon-S 100mm f5.6. Focusing wide open at 5.6.

 

[Patrick Robert James]

Do you have a glass negative carrier? Most regular carriers don't hold the film flat and you get exactly what you describe.

You can check your laser by spinning it around 360º. The dot shouldn't move.

 

[xkaes]

What grain focuser?

 

[Pieter12]

Thanks for the replies! Componon-S 100mm f5.6. Focusing wide open at 5.6.

What size film? A 100mm is not going cover 4x5. If you are enlarging a smaller negative, try stopping down 2 stops and recheck if the grain is sharp in the center and corners. Focus can shift when stopping down.

 

[Photopathe]

I have 4 grain focusers and they are all in concordance (Bestwell microsight, peak model 1 and 2, and Bestwell minisight).
I was trying with a 35mm film.
My bad, I didn't have the reflex to check film flatness. I was using glassless but I do have one with glass for 4x5. I sometimes use tape on the edge of the film to maintain flatness without using glass.
I usually do stop down 2 stops but after achieving focus wide open. Then I do recheck focus. Is that not good practice to first achieve critical focus wide open? Is there more field curvature wide open or is the difference only depth of field?
Componon-S should be flat enough, right?

I can't get back to it until tomorrow or Tuesday evening. Will try again (after making absolutely sure film is flat, silly me) then and report back.

 

[Pieter12]

I have 4 grain focusers and they are all in concordance (Bestwell microsight, peak model 1 and 2, and Bestwell minisight).
I was trying with a 35mm film.
My bad, I didn't have the reflex to check film flatness. I was using glassless but I do have one with glass for 4x5. I sometimes use tape on the edge of the film to maintain flatness without using glass.
I usually do stop down 2 stops but after achieving focus wide open. Then I do recheck focus. Is that not good practice to first achieve critical focus wide open? Is there more field curvature wide open or is the difference only depth of field?
Componon-S should be flat enough, right?

I can't get back to it until tomorrow or Tuesday evening. Will try again (after making absolutely sure film is flat, silly me) then and report back.

Using a 100mm for 35 you are definitely in the sweet spot of that lens. Is everything level with your easel? It seems like your focusing method and everything you've done for alignment is good. I don't think a 35mm negative in a glassless carrier would buckle enough to give out-of-focus corners stopped down.

 

[wiltw]

Thanks for the replies! Componon-S 100mm f5.6. Focusing wide open at 5.6.

Componons are not cheapo beginner lenses!

 

[gone]

FWIW, for the longest time I didn't have a grain focuser. Just used a 135mm lens to see if the shot looked sharp on the print easel w/ a piece of paper in it and made my prints by that. Can't remember if I turned the lens around backwards or not for that purpose. Now I have a very good grain focuser, but haven't seen any difference in the prints.

And yes, a Componon is a higher quality lens than a Componar. Whether you will see any difference on your prints I don't know, maybe yes, maybe no, depends on how big you're enlarging probably. To me, the main advantage of a higher quality (more expensive) lens is that they nearly always are faster, so they're brighter and easier to focus.

 

[ic-racer]

Glass negative carrier will keep the negative flat and resolve the issue.

 

[Sirius Glass]

When I was shown a grain focuser, it became much easier to focus much faster and sharper.

 

[snusmumriken]

Hi! I have a Beseler 45MX and a Versalab Parallel alignment tool which has been calibrated very recently by the manufacturer. Apparently I successfully aligned the negative stage by sandwiching the alignment glass in the negative carrier. I then aligned the lens by attaching the glass in front of then. So far so good, but then if I try to focus on the grain across the whole image on the lens board it doesn't work. I focus on the central part and then move the grain focuser close to the edge of the image and I need to adjust focus as I don't see the grain there. Going back to the central part, no surprise, focus is off. What could be wrong? I'm puzzled.

Quite a few grain focusers (e.g. the Paterson ones) don't work at all (no image) in the outer field. I forget why, it's something to do with the angle at which the image rays strike the mirror. Even if my focuser did produce an image out there, I'm not sure I would trust it until someone had convinced me that the longer light path in the outfield didn't affect the place at which the device focused. Tim Vitale has argued that because the device is focussing on a grain clumping illusion that has depth in the emulsion, rather than precisely defined silver particles, using eyesight to seek maximum micro-contrast is a better guide. I find that persuasive in theory and at least as good in practice.

I don't know whether it is possible to achieve perfect focus across the entire image area at high enlargement factors. My experience, even with a good enlarger lens, has been that this is a game of compromise where you get things as good as you can but ultimately cover for inaccuracies by stopping down.

A glass negative carrier will hold the film flatter, but it adds 4 more surfaces to hold dust, and may cause Newton rings. If you don't intend to use such a carrier normally, using it to align your enlarger may be hiding from you the compromise you really need to make.

 

[logan2z]

A glass negative carrier will hold the film flatter, but it adds 4 more surfaces to hold dust, and may cause Newton rings.

IME, the pros outweigh the cons, as long as you have a glass carrier with Anti-Newton glass.

 

[Pieter12]

Quite a few grain focusers (e.g. the Paterson ones) don't work at all (no image) in the outer field. I forget why, it's something to do with the angle at which the image rays strike the mirror. Even if my focuser did produce an image out there, I'm not sure I would trust it until someone had convinced me that the longer light path in the outfield didn't affect the place at which the device focused. Tim Vitale has argued that because the device is focussing on a grain clumping illusion that has depth in the emulsion, rather than precisely defined silver particles, using eyesight to seek maximum micro-contrast is a better guide. I find that persuasive in theory and at least as good in practice.

I don't know whether it is possible to achieve perfect focus across the entire image area at high enlargement factors. My experience, even with a good enlarger lens, has been that this is a game of compromise where you get things as good as you can but ultimately cover for inaccuracies by stopping down.

A glass negative carrier will hold the film flatter, but it adds 4 more surfaces to hold dust, and may cause Newton rings. If you don't intend to use such a carrier normally, using it to align your enlarger may be hiding from you the compromise you really need to make.

I don't think the OP is dealing with high enlargement factors using a 100mm lens for 35mm film. The head might be high and the image dimmer, neither of which should affect the sharpness across the image on the easel.

 

[mshchem]

When I was shown a grain focuser, it became much easier to focus much faster and sharper.

When I was a kid I remember thinking I don't need a grain focuser. Sure comes in handy now.

 

[Todd Barlow]

Not withstanding the other suggestions that may identify the issue, I would add the following.

Check the level of the baseboard. Left-Middle-Right, Front-Middle-Back, Diagonal. The Parrallell stays in the middle of the baseboard under the lens. I have been aligning my 45MXT and MXII and have found the baseboards both needed shimming.

Todd

 

[Paul Ozzello]

A couple of thoughts.
I remember back in the day that some lens stop rings weren’t perfectly parallel to the lens’ optical path. Maybe you can remove the lens and attach the glass or mirror to the lens mount.

You really have to have the negative in a glass carrier for absolutely perfect flatness - any slight buckling or curvature will be magnified exponentially.

Most grain focusers have a difficult time focusing on the edges. If I remember correctly my Peak focuser had an adjustment similar to the Silvestri glass loup and could focus on the edges.

And if you haven’t been doing so make sure to use the grain focuser on top of a sheet of the same paper that’s in your easel.

 

[Sirius Glass]

When I was a kid I remember thinking I don't need a grain focuser. Sure comes in handy now.

With age comes wisdom and reading glasses.

 

[Photopathe]

The baseboard is level with the enlarger head, I doubled check yesterday. I taped the edges of the negative on the negative holder and I stopped down 2 stops. I was finally able to see sharp grain over the whole 8x10 area. I guess the problem was a combination of factors. I wanted to start by achieving critical focus over the whole printing area without stopping down, the negative was probably not perfectly flat, and to add to this one end of this negative is quite underexposed (ie quite clear with grain difficult to see).
Is it not better to be able to achieve critical focus over the whole area before stopping down (even if it is necessary to recheck focus because of possible shift)? Is stopping down without doing so just hiding a problem?
I find this enlarger not so convenient to align. I align the negative stage first by aligning the whole head the way I explained at the beginning of the post (sandwich the glass of the Parallel Versalab in the negative holder) and then I proceed with the lens stage. To adjust the lens stage I need to loosen the screws of the spring mechanism that holds the lens board and fiddle with the lens board. It's not practical at all for the lens stage and not so stable and need to be repeated each time. I wish there was another way (without throwing more money at it by changing enlarger...). If anyone also has advice on that it would be great.

 

[btaylor]

I’m not sure if I am reading your problem correctly, but I have a Beseler 45 and the Versalab alignment tool. I have also had trouble getting the lens stage into alignment. I have heard that people shim the stage with paper or cardboard. There is also an adjustable lens board Beseler made. I have one but haven’t used it yet. I loosen the mounting screws of my turret and force it into alignment and it seems to stay put. As a safety I’ll use some tape as well. Kinda funky but it totally works. Easier than changing enlargers!

 

[GregY]

All of the lenses f(50,80,105,150) for my 45MXT are on Beseler adjustable lensboards.

 

[wiltw]

The 45MZ parallelogram frame enlargers are known to be somewhat more finicky than enlargers with central post. There are also inherent limitations in adjustability, some of them specific to one model vs. another model of 45MX series.

Beseler 45MX Enlarger Alignment

I have been able to align my Beseler 45MX enlarger side-to-side and front-to-back with respect to the baseboard per the instruction manual, but I still have some un-uniformity in focus. I haven't been able to find any adjustment screws or instructions on how to adjust the lens board and...

www.photrio.com

In addition there can be other issues, with the focusing stage.

"Reducing slack in focusing rail​

On focus, I could feel the bottom stage shift left to right. This was unrelated to the swing and is caused by the nylon rails either being worn out or the bolts and set screws being too loose against the focus rail." https://justinribeiro.com/chronicle...ck-and-alignment-in-the-beseler-45mx-enlarger"​

...fortunately gives some very specific instructions about what might be done.

The former product manager for the 45MZ and CB7 enlargers noted that in his own enlarger, there was a slight L-R difference in focus, if you best focused one side the other would be slightly out. He also noted that there was not a way to align the lens board and negative carrier relative to each other.

 

[Jim Jones]

Where there are no adjustments provided to adjust the negative holder to lens board alignment, perhaps either the holder or lens board can be shimmed with Scotch Magic Tape, about .002 inches per layer.