105mm lens board for Beseler 23Cii

[punkzter]

I recently acquired a Beseler 23Cii so that I could make prints from 6x9 negatives. If I'm reading the instruction manual correctly, I need a #8029 lensboard to do this.

Is it really the case that you need different lens boards for the different size lense? How are you suppose to tell the boards apart, they don't appear to have a product number stamped anywhere on them.

Anyhow, I went on ebay and bought a board with a 105mm lens attached to it. I may end up sending it back, because the lens has what appears to be some fungus in it.

This is what I bought:

https://www.ebay.com/itm/Schneider-...e=STRK:MEBIDX:IT&_trksid=p2057872.m2749.l2649

But that leaves me still searching for a 8029 lensboard. There is another on ebay:

https://www.ebay.com/itm/Beseler-en...976539?hash=item54835a279b:g:jUIAAOSwcLlepzfj

It says that it has a 5/8" extension and a 32mm hole. They say that is standard, but I thought 39mm was standard.

Both boards look different. If anyone can help me understand what the deal with lensboards is, that would be awesome!

Thanks,
Brad

 

[punkzter]

Or, am I approaching this the wrong way. With a beseler, do I need to find a lens first, and then find the correct board?

 

[MattKing]

The extended mount is what you most likely will require for a 105mm lens. The lens and board that you bought might work, but it also might restrict your magnification range.
Different 105mm lenses will have different threads.
39mm is the most common thread size, but there are a bunch of alternatives.
This page on KHB's site gives a sense of the range: http://store.khbphotografix.com/Beseler-Lens-Mounts/
It is best to decide on the lens first, and then get the board appropriate for it.
Don't forget the retaining ring.

 

[punkzter]

So, for example, the 35mm lensboard (8021) has a counterbore on one side of the board. The 6x6 lensboard (8023) has it on the other side. My enlarger only came with the 8023 board. Just how important is it to have the board for 35mm with the counterbore on the opposite side?

It seems so minor, but they clearly made separate boards.

 

[voceumana]

Note also that 39mm extension tubes are available. Nikon made one for a short extension of about 15mm, but general purpose ones are also made for Leica screw mount and others. It has the advantage that the tube is mounted with a retaining ring to the lensboard but it is threaded, so no ring is needed for mounting the lens--it just screws in.

 

[John Koehrer]

Not at all important as long as the lens fits. Some people having only one lens board will just
swap the lens but both 50 & 80 use the flat board.
If you're concerned about the light pipe for the aperture ring, as long as it faces downward you're OK.
Some newer lenses like the newer Rodagons don't need the pipe because the illuminator is built into the lens.

 

[punkzter]

Okay. Thanks for the help!

 

[MattKing]

So, for example, the 35mm lensboard (8021) has a counterbore on one side of the board. The 6x6 lensboard (8023) has it on the other side. My enlarger only came with the 8023 board. Just how important is it to have the board for 35mm with the counterbore on the opposite side?

It seems so minor, but they clearly made separate boards.

Some of these sorts of differences may be related to how much the lens protrudes behind the board.

 

[voceumana]

Also, the original 23C enlargers had a filter drawer just behind the lens, so protrution of the rear of the lens could cause interference. I'm not sufficiently knowledgeable about the 23C to know which version got rid of that.