Bessler 23C Negative Popping Problem

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Dec 26, 1996, 3:00:00 AM12/26/96

I have one of the "classic" blue Bessler 23CIIs. It does not stay in
focus. I have discussed this problem with Bessler technicians and various
local repair people. I replaced the focus springs in the focus block and
tightened them down per the Bessler recommendations. If I put a negative
in (35mm) it not stay in focus. Here's the weird part: It is slipping UP
out of focus. I have to nudge the focus wheel down to get it exactly back
in to focus. However, if I leave the enlarger light on, it stays in

My conclusion is that the problem is not related to mechanics of the
enlarger. I believe the problem is a phenomenon called "Negative
Popping". This concerns the heat of the lamp on the film backing.
Bessler has two solutions, both about $25 locally: (1) Heat absorbing
glass, which has been around a while and (2) a new product they call a
Temp-guard filter.

Has anyone else had this problem and/or solved it with one of the two
fixes above? Also any other thoughts/ideas?

Thanks and cc's to my email address appreciated.

Rick Schiller

Richard Knoppow

Dec 26, 1996, 3:00:00 AM12/26/96
to (RSchllr) wrote:

You should be able to confirm the negative popping with a grain
magnifier. Let a negative get good and warm and then focus it
sharply. Let the machine cool for a few minutes and then turn it on
again while watching through the magnifier. If its popping you will
see an out-of-focus image that will drift back into focus after it
gets warm. A glass type negative holder is the ultimate cure for this
(at the price of four more surfaces to keep squeaky clean). I
sometimes have to resort to using the red filter as a lens cap so that
I can leave the light on between focussing and inserting the paper. I
then turn the lamp off for just long enough to swing it away and start
the timer.
Heat absorbing glass will certainly help. If you are doing color
work you should have the heat absorbing glass anyway.
Richard Knoppow
Los Angeles, Ca.

Sam Beavin

Dec 26, 1996, 3:00:00 AM12/26/96
to RSchllr

You might also try placing a piece of the heat absorbing glass in the
large filter drawer. Bessler makes this but I've now idea what the part
# might be. I use one and have never had a negative of any size pop.
Good luck.
Sam Beavin


Dec 27, 1996, 3:00:00 AM12/27/96

I have the same enlarger, and one solution I have found, when I have this
problem (don't always have it, especially with 35mm), is to use a Beseler
4x5 Universal neg holder, which has the anti-Newton glass. If you drill
out the four rivets that project out from the bottom plate, it will fit
perfectly into the 23CII. As far as I know, Beseler does not make a
universal neg holder, with Anti-Newton glass, specifically for the 23CII.
Good luck.


Jan 1, 1997, 3:00:00 AM1/1/97

Probably the simplest and cheapest way to solve your problem is to tape
your negatives down to the negative carrier. Start by taping down one side
and then place tape on the other side of the neg. and pull it tight while
you place it in place on the carrier.

You might also want to consider investing in a cold light head for the
enlarger. Not only will this stop your negatives from popping, you will
also produce much more beatiful prints.

Good luck!


Jan 2, 1997, 3:00:00 AM1/2/97

I just encountered a bad negative popping situation with a 23C,
which is why I just learned that Beseler makes a couple of cheap
accessories that might come in handy. One is item 8042, heat
absorbing glass, which >I THINK< is just a piece of glass in a frame
that goes in the filter drawer and blocks the IR light and, therefore,
the heat.

They also sell an item 8132, which is a heat filter. I don't know what
this is, but when I called Calumet, both items are the same price
($27.39), so I suspect they're pretty similar.

I have no experience (yet) with either item, but I plan to, soon....


Luca de Alfaro

Jan 6, 1997, 3:00:00 AM1/6/97

I had the same negative popping problem, and I solved it completely by
buying the Beseler heat absorbing glass, at $25-30. This solution is
less expensive than glass negative carriers or cold lights, so you
might want to consider it first. B&H and Adorama should carry the

Luca (


Jan 7, 1997, 3:00:00 AM1/7/97

I too had the same problem with damp negatives (San Francisco) with a warm
enlarger. Beseler makes a glass universal (6X9) holder available with or
without the anti-Newton glass (which you definitely need for 35mm negs).
Be advised 1) that for some strange reason one still has to hand file the
edges to get the rebate area of a 6X6 negative to print and 2) I needed
to shim the the anti-Newton glass with tape to get enough pressure to hold
the negative securely between the glass plates. I always wonder if
Beseler every lets any photogs beta test their products.

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