Beseler 23CII Focusing problem

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Midoriyama

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I have noticed that my enlarger loses focus between the time I focus and frame the negative on my easle to the time I load the paper and expose.
I have repeated the problem several times without paper in the easel just to confim I wasn't seeing things. But lo and behold, the 30-45 seconds between turning off the enlarger, loading the paper, and then exposing, the image is out of focus.
The only thing I can reasonably link this to is the change in temperature in the bellows from when the light is on then off thus causing the negative to warm and cool changing its shape.
Has anyone else encountered such a problem (regardless of the brand/type of enlarger) and what did you do to remedy the problem?

Thanks:bang:
 
If your problem is the negative flexing in the carrier, there are a couple of things you can do.
Heat absorbing glass mounted in the system between the bulb and the negative should reduce the likelihood of this happening. The glass doesn't materially change printing times, mostly absorbs IR and keeps the negative from heating up nearly as much.
The other possibility is a neg carrier with glass sandwiching the negative. These are expensive and a pain to use by nearly all accounts, but eliminate the problem completely. Glass carriers are troublesome because they require 4 extra surfaces be kept perfectly clean and because newton rings are a possibility unless special AN glass is used above the negative.
I try to enlarge with the lens stopped to F/8 or F/11 to minimize these problems. My 23c produces plenty of light and to keep exposures reasonable I also often have to use a ND filter.
 
It does sound like the negative is "popping". One way around it, without the glass negative carrier, is to leave the enlarger light on with it's red filter in the light path after focusing and while putting paper in the easel, then turn the enlarger light off, swing the red filter out of the way, and make the exposure. Once you get the hang of it, it becomes very fluid and I've yet to see evidence of paper fog. You'll want to have the lens stopped down to the working aperture while putting the paper in. My medium format negatives "pop" and I use the above method to get around it.
Good Luck!!
 
I've been looking for one of these glass AN carriers and no luck.
I cant bring myself to spend upwards of $180 for a new one.
 
The last enlarger I used was a Beseler 23CII. Have you checked if the focusing
rack is loose? Or if the lens board is properly fixed by the clamping springs?

I don't have any of the original - or even 'real'- negative holders. I used DIY holders made of cardboard (illustration board) and never had any focus shifting due to warping negatives. The Beseler's jaw-like, clamping negative stage is heavy enough to bear down on the cardboard carrier to keep it flat not just during focusing, but even through the entire exposure period. With the real metal negative carriers, the warping and popping issues in this case would even be far more unlikely to happen.

Besides, I don't think the negative will even move to a very significant degree in just a few seconds that the lamp is on. Heat is there, but the Beseler's efficient cooling head would prevent the negative from heating up enough to cause warping. I've used both condenser (with 150W, double the recommended 75W without heat absorbing glass), as well as the DGA dichro head (using an even hotter 350W halogen lamp) illumination with the Beseler. I've never encountered any focus shifting at all.

Try to see if the parts attached to the focusing knob is loose.
 
I have the same enlarger. I'll suggest one more possible reason based on personal experience. I used to get out-of-focus prints based on the following scenario:

When I am bend down looking through the focuser I will reach up with my right arm and turn the dial on the head to bring things into focus. The weight of my body being low while my arm is raised and turning the dial will create a situation where I am inadvertently slightly pulling the head down and causing the connected column to flex. That little bit of flex will be constant while I focus so I don't notice it while doing fine-focusing. Then after focusing I let go of the dial and, without me knowing it, that takes the strain off the column and the enlarger head goes back ever-so-slightly to its normal position. Then I'm puzzled why my ensuing print is out-of-focus.

I should add that the problem was the same, of course, when using regular negative carriers and glass carriers.
 
My first thought was that the neg was "popping" too...
Another thing you want to do is NOT focus on the easel's surface but on a old exposed sheet of what ever photo paper you're using...(use the back side of an old photo, place it in the easel like you would when exposing a good sheet)
The difference isn't huge but everything helps...
Also focus on the film grain not on the actual image...
 
I had a 23c for all of two weeks. It is notorious for not keeping alignment because of its adjustable lens/negative stage. I would suggest buying a small lline evel and make sure the negative stage is parallel to the base board.
 
I have a 23C and have never had that problem. I would second the idea of focusing on the back of a print.

The adjustable negative stage is designed to be locked down with bolts once it is aligned. I've never found mine to need adjustment in the two to three years I've used it. In fact, after careful checking, it was properly aligned the day I got it (used.) If you don't tighten the fasteners or they are stripped, I guess it could be a problem. But I fail to see alignments as a flaw :shrug:

I can't really see any way for the entire assembly to lose focus due to slop unless your gears are excessively worn or the fasteners are all loose. Beseller does sell pretty much everything on the assembly, so if you have a problem with the gears or something, it's easily addressed.

The focus mechanism should not be so loose that the bellows could possibly change focus simply by warming and cooling. If it is, it needs to be tightened or it's shot and should be rebuilt.
 
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I was having this problem with MF negs when I first got my 23CII.
Two things got it sorted for me.
Firstly I ensured that the head was level and sorted out according to the manual, and that the bands which tighten the focusing dials were nice and snug.
Secondly, I got the heat absorbing glass on e-bay. This was arguably the most important.

Hope you get it sorted out,
Kent
 
I checked my newly acquired 23c II w/Dichro Colorhead in this fashion...

Instead of a level or square I decided to use a Dial Indicator (I use these tools for adjusting Parallel on Printing Presses)
I placed the enlarger on a table and set up the Dial Indicator to sit flat on the baseboard and then positioned the Indicator's point to the Lensboard, Zeroed the Dial and then took measurement from side to side and then front to back...if any adjustments were made I would recheck everything again...Right now it's within +/-.002" from any point...
Printed and all looks good...will check again later if I feel the need is there...
I then checked my other enlarger and found it was off too...Haven't printed with it since but will check it out soon...
 
I've had my 23C since 1966; very solid and not prone to go out of adjustment. I have periodically checked the alignment with a carpenter's level, mostly when moving it to a new space, and when I put the dichroic head on... or again after I've used the negative-stage tilt feature.

There is certainly a "pop" from heating up the neg, depending on humidity etc, same as with slides in projectors. Several good suggestions above for dealing with that.
 
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