besler 4x5 MX II adjustments

[esearing]

Some friends gave me a nice used Beseler MXII enlarger which has one issue I can seem to rectify. The top and bottom plates that hold the film holder do not clamp down tightly and have a slim horizontal light leak around the room. Is there some way to adjust the height a fraction of an inch so they close tighter. I am using the round Beseler 4x5 film holder and its pins fits nicely in the circular opening.

2nd issue: I put a new 250W bulb into the 45Dicro head and zero'd the color filter values. The recommendation by Ilford is 41Yellow and 32Magenta for grade 2 on Classic MG Fiber paper.
I have run some contact prints and found that too contrasty compared to a filter under the lens. I cut magenta down to 16 and got closer. Is this common due to new bulb, or possibly the mixing chamber? Any adjustments recommended or merely alter print by print?

[chassis]

esearing,

It sounds like you are referring to light leaking where the light source meets the negative carrier. Is this the correct understanding? I just checked my Beseler 45 condenser light source, and there are 2 possibilities for adjustment. I don't know if your light source is similar in this respect.

There are screws which attach the plate which bears against the top of the negative carrier. This plate also happens to be attached to the lower end of the bellows to which the light source itself is attached. The attachment screws could be loosened and some adjustment may be possible. There is also an adjusting knob used to change the height of the light source relative to the negative carrier. The aforementioned plate is attached by set screws to the knob.

If you can post a photo of your setup it will help others to give you guidance.

The bottom plate on which the negative carrier can also be adjusted, but this needs to be perpendicular to the lens axis and parallel with the easel/enlarger table. So fixing light leaks at the negative stage needs to be addressed by adjustments in the upper plate.

[esearing]

159169

Apparently this is common and some have recommended using foam or cork adhered to top.

[Alan9940]

esearing,

Suit yourself, of course, but I have used a Beseler MXT for nearly 40 years using a few different cold light heads and I have always had tiny bits of light leak around the negative carrier and from where the light source sits on top because cold light units, at least the ones I've used, simply slide into the round chamber in the upper staging. I've used this enlarger in 3 different darkrooms now, tested for fogging of the paper after each darkroom move, and never had an issue. I've had issues with some safelights, but that's a different problem. ;) Have you tested for fogging to determine if the light leaks are a real issue?

Good luck!

[LabRat]

With any recently acquired Beseler, the first thing to do is to prepare to order the replacement for the material that allows the upper & lower standards to slide along the monorail between them... (Older ones had pads that they slid on, while the newer ones have nylon bushings that they slide on...) They are usually worn, and the standards will not sit square on the rail (with your leak problem), will not slide correctly, and affect stage alignment... Get some while they are still available, and a spare set...

When installing, do not tighten the gib screws over them too tight, as that will bend the supporting plate under them, just barely snug...
An upgrade there would be to get a piece of 1/4" X 3/8" aluminum bar stock to make replacement supporting plates that will not bend, cut/drill/tap for new extended gib screws + locking nuts, and those will be a big upgrade...

When that is done, the light leak should be less than a razor's edge thick, the standards will slide better, and the head will be in MUCH better alignment...

I agree with Alan, small light leaks on the side of the head will usually not do much, but light leaks that can be seen looking from below the lens area can project pinhole double images that will expose on fast papers (like color Type C, or some RC B/W papers), so be concerned about those mostly... You can test your enlarger set-up for fogging by exposing photo paper for a very long time with a lens cap on, and developing the sheet, and look for any smudges of fogging on what should be a blank, white sheet of "exposed" photo paper...

Sometimes there is a light leak where the red filter slides in, but a little black photo tape will help there... Go through the entire head, and sometimes a gap can be filled with low density foam weatherstripping from you home store... (Grey is OK, as it will seal well once compressed...)

Steve K

[esearing]

Thanks Steve K I will look for those bushings. I'll need to find some assembly plans.

The light leak is significant due to my tiny closet darkroom. 1/8th inch opening of light blasted in all directions reflecting off of white walls within 2-3 feet of the enlarger plus reflection off my glasses is enough to be concerned about.

In newer enlargers there seem to have a much better design for the negative carriers that fit into a drawer. I wonder if I could 3D print a "drawer" that sits within the stages, extends outside and yet has an opening for the holder to drop into. Might be a fun project. |___ ___|

[Steve Goldstein]

For a long time I got by with black flocking taped to the walls around the enlarger, a 45MX with an Aristo cold light head. But then I got motivated...

First, I built a little filter drawer using solid black mat board (non-archival, I'm afraid) that sits atop the negative stage. It has baffles along the outer edges that block much of the light, and it has enough clearance that I can exchange filters without having to refocus. This is really handy for split printing, low-contrast edge burns, and the like.

Second, I place a black towel over the head and extending down past the edges where the light leaks out. Crude but effective.

It helped a bit to carefully remove the glass from my glass carriers and blacken the edges all around with a Sharpie. Make sure not to mix up the pieces if you're using Anti-Newton glass on top.

I don't know that any of this made a real difference, but it makes me feel better...

[Alan9940]

The light leak is significant due to my tiny closet darkroom. 1/8th inch opening of light blasted in all directions reflecting off of white walls within 2-3 feet of the enlarger plus reflection off my glasses is enough to be concerned about.


Yep, that sounds like a lot of light leaking! Mine is just slivers of light; that is, you can tell when the head is on simply be looking at the head/negative stage assembly, but nothing like what you describe. In my previous darkroom, where the walls were within a couple feet of the enlarger on two sides, I painted the walls black. Not sure if I really had to do that, but like Steve said, it just made me feel better.

Good luck!