Enlarger Question regarding condenser enlarger (in)consistency: Beseler 23c

[Premier]

Hi all,

I was experimenting trying to print a zone V gray on my Beseler 23c enlarger (condenser version), and notice this apparent "cool spot" in addition to some modest falloff. The spot hits close close to the operator side of the board as projected/printed. Does anyone know what might be causing this? It seems like something that will affect prints. I am just learning to print with an enlarger. Any suggestions/ideas would be welcome.

Thanks

 

[mshchem]

So obvious question, do you have the condenser adjusted to the correct size negative carrier. Correct lens? Is the enlarger in focus?

You need a carrier, correct lens, condenser set, in focus.

 

[mshchem]

That's a great enlarger

 

[mshchem]

Not sure what era, some (all?) have a tilting lens stage, make sure it's zeroed. There's a sliding filter drawer right above the lens, make sure it's pulled out.

 

[chuckroast]

Hi all,

I was experimenting trying to print a zone V gray on my Beseler 23c enlarger (condenser version), and notice this apparent "cool spot" in addition to some modest falloff. The spot hits close close to the operator side of the board as projected/printed. Does anyone know what might be causing this? It seems like something that will affect prints. I am just learning to print with an enlarger. Any suggestions/ideas would be welcome.

Thanks

Make sure someone didn't install a regular lightbulb with lettering on the crown of the glass. Enlarger lightbulbs are specifically made to avoid anything on the bulb that could project onto the image surface.

Also check that various condenser elements to make sure they are clean and do not have cracks or imperfections and that you've cranked the condenser into the position appropriate for your film size.

 

[Maris]

I've had spots like that when making grey values on photographic paper with no negative in my Omega D2V condenser enlarger.
Because there was no negative present the raw enlarger light was very bright and required the enlarging lens to be stopped right down even to f45.
At f45 the depth of focus of the lens becomes great enough to reach up into the condenser system and form blurry images of dust spots on the glass surfaces.
When I cleaned the condensers the spots went away ... thank goodness!

 

[Kino]

Hi all,

I was experimenting trying to print a zone V gray on my Beseler 23c enlarger (condenser version), and notice this apparent "cool spot" in addition to some modest falloff. The spot hits close close to the operator side of the board as projected/printed. Does anyone know what might be causing this? It seems like something that will affect prints. I am just learning to print with an enlarger. Any suggestions/ideas would be welcome.

Thanks

The 23C has a screw that locks down the enlarging lamp. I found on mine, I could place the head on the 2 1/4 x 3 1/4 setting with a 75mm Nikkor enlarging lens and NO negative carrier, loosened the screw and the lamp would slide around a bit.

I noticed it could effect the uniformity of the transmitted light (lens wide open), so I experimented with moving it around until I got the best coverage tightened-down. Takes a bit of playing around (the tightening of the screw does shift it a bit) and it's not perfect, but I have not noticed any printing problems with obvious fall off on any side of the easel.

The negative carrier obviously restricts the edges of the light beam, so as long as you get it as uniform as possible, you should be fine.

 

[xkaes]

Great suggestions so far. Could be lots of things. Here's two more: What contrast paper was used? Do you have the user manual so that you check to make sure everything is set to the factory standard correctly?

 

[Patrick Robert James]

Condensers have to be perfectly clean and clear. Any scratches or dust is an issue. I'd inspect them to see if they are ok.