Beseler 23C lensboard for 80mm lens

[logan2z]

I recently picked up an 80mm/5.6 Nikon Nikkor enlarging lens for printing from 6x6 negatives. I have an existing lensboard for my 50mm lens (I believe it's the 8021) but I see there is a specific board - the 8023 - for use with longer focal length enlarging lenses. It's not exactly clear to me what the difference is between the boards or why the 8021 wouldn't be appropriate for use with an 80mm lens. Can anyone enlighten me?

 

[voceumana]

The various Beeler lens board provide different recesses or extensions to account for some of the lens focal lengths. Short focal lengths sometimes need to be closer to the negative, so a recess helps; longer focal lengths may need extensions. The differences account for the limited bellows extension and compression to keep the lens where it can be focused.

Most Besseler lens boards are unthreaded and require a jam nut. If you get a threaded lens board, you can just change lenses by unscrewing the lens rather than replacing the entire lensboard and lens. See: http://store.khbphotografix.com/39mm-Threaded-Lensboard-for-Beseler-23C-and-4x5-Enlargers.html

As an alternative, if you can tolerate the extra extension, Nikon and others made a short 39mm extension tube that could be mounted to a plain lensboard with a jamb nut, and then you can screw the lens into the extension. Probably that would work for the 80mm, but might give too much extension for 50mm.

 

[John Koehrer]

The 8023 has a counterbore on the top/back of it for lenses that use a jam nut.
I believe it may have the illuminator for the f stop also other than that it's a blat lens board.

 

[logan2z]

The various Beeler lens board provide different recesses or extensions to account for some of the lens focal lengths. Short focal lengths sometimes need to be closer to the negative, so a recess helps; longer focal lengths may need extensions. The differences account for the limited bellows extension and compression to keep the lens where it can be focused.

Most Besseler lens boards are unthreaded and require a jam nut. If you get a threaded lens board, you can just change lenses by unscrewing the lens rather than replacing the entire lensboard and lens. See: http://store.khbphotografix.com/39mm-Threaded-Lensboard-for-Beseler-23C-and-4x5-Enlargers.html

As an alternative, if you can tolerate the extra extension, Nikon and others made a short 39mm extension tube that could be mounted to a plain lensboard with a jamb nut, and then you can screw the lens into the extension. Probably that would work for the 80mm, but might give too much extension for 50mm.

Thanks for the info. I mounted the 80mm lens on my existing lensboard and I didn't seem to have any issues getting things in focus. It is, however, a bit of a pain to remove the lensboard to change lenses so I might look into a board that is threaded.

 

[Ian C]

Any of the Beseler or Delta-1 4” x 4” x 1/8” flat lens boards of the appropriate lens-hole size will work with an 80 mm enlarging lens on the Beseler 23C-series enlargers. This will allow plenty of focusing range for the amount of bellows movement available.

The Beseler enlargers are generally robust machines. There are a few possible problems. The spring of the lens board retainer is poorly-executed on some 23C enlargers. The following thread discusses how to analyze and correct the spring. In some cases you might have to get a new spring.

With a spring of the proper shape installed, lens changes are smooth and easy. If the spring is miss-formed, installing/removing the lens board can be difficult. In some cases, the retainer might have to be partially disassembled to release a lens board with a misshapen spring.

https://www.photrio.com/forum/threa...nsboard-into-a-beseler-23cii-xl-dichro.94439/

The purpose of the counterbore is to THIN the lens board so that sufficient thread length will extend to the other side of the board to install a retaining ring. Some enlarging lenses have short mounting threads necessitating a thin board. The alternative is to buy a board with a threaded flange installed so that the lens can be screwed into the flange.

 

[logan2z]

Any of the Beseler or Delta-1 4” x 4” x 1/8” flat lens boards of the appropriate lens-hole size will work with an 80 mm enlarging lens on the Beseler 23C-series enlargers. This will allow plenty of focusing range for the amount of bellows movement available.

The Beseler enlargers are generally robust machines. There are a few possible problems. The spring of the lens board retainer is poorly-executed on some 23C enlargers. The following thread discusses how to analyze and correct the spring. In some cases you might have to get a new spring.

With a spring of the proper shape installed, lens changes are smooth and easy. If the spring is miss-formed, installing/removing the lens board can be difficult. In some cases, the retainer might have to be partially disassembled to release a lens board with a misshapen spring.

https://www.photrio.com/forum/threa...nsboard-into-a-beseler-23cii-xl-dichro.94439/

The purpose of the counterbore is to THIN the lens board so that sufficient thread length will extend to the other side of the board to install a retaining ring. Some enlarging lenses have short mounting threads necessitating a thin board. The alternative is to buy a board with a threaded flange installed so that the lens can be screwed into the flange.

Thanks for the reply and the link to the other thread.

Luckily I don't seem to have an issue with the spring in my 23CII and I am able to remove the board without issue. Well, the only issue I have is that there's really nothing to grab onto - other than the lens itself - in order to push the board back to disengage it. I don't love the idea of pushing on the lens to remove the board. I see that the 8021 pictured at BH Photo has two knobs on either side of the lens. I'm wondering if those are there so that there's something to grab onto when pushing back the lens board. Or maybe they're for something else, but my lens board doesn't have them.

 

[Ian C]

Those two thumbscrews are for mounting a filter holder. Many Beseler boards are plain, so that the lens is the only option as a handle. If the lens-board retainer is working properly, the amount of force involved is modest, certainly not enough to harm the lens. Other Beseler boards have a handling knob attached.

For example, the Beseler recessed lens board sinks much of the lens deeply into the board so that using the lens as a handle is awkward. That’s why this board has a handling knob in addition to the filter-holder thumbscrews. I have one of these for a 40/4N El Nikkor. I found the knob too small to be practical. I installed a larger handling knob from my local hardware store, making installing/removing the board & lens fast and easy.

https://www.bhphotovideo.com/c/product/4533-REG/Beseler_8022_39mm_Lensboard_with_5_8.html

If you want a handle on a flat board, you can find a suitable handle at a hardware store and attach it to the bottom surface of the board, Be sure to mount it away from front edge of the board where it must move forward about 2 mm or so under the front retaining plate.

Another easy way to add a serviceable handle is buy a 1” x 3/8” diameter nylon spacer at a hardware store. These have a through hole for a #6 machine screw. I found that a #6-32 x 1.25” cap screw is a good fit.

You can drill & tap a hole in the board or use a #25 drill (0.1485” diameter) to make a screw-clearance hole in the board, If you use the clearance hole for the screw, it can be secured with a nut on the top side of the board. If you tap the board, it’s a good idea to apply Locktite 242 REMOVEABLE thread locker to the thread of the screw before installing and tightening the screw. Not counting the thread-locking compound, the cost of the spacer, screw, and a washer under the screw head cost less than $1.00.

The Beseler board equipped with a handle places the center of the hole 11/32” (8.73 mm) from the front edge of the board and centered from left to right.

 

[logan2z]

Those two thumbscrews are for mounting a filter holder. Many Beseler boards are plain, so that the lens is the only option as a handle. If the lens-board retainer is working properly, the amount of force involved is modest, certainly not enough to harm the lens. Other Beseler boards have a handling knob attached.

For example, the Beseler recessed lens board sinks much of the lens deeply into the board so that using the lens as a handle is awkward. That’s why this board has a handling knob in addition to the filter-holder thumbscrews. I have one of these for a 40/4N El Nikkor. I found the knob too small to be practical. I installed a larger handling knob from my local hardware store, making installing/removing the board & lens fast and easy.

https://www.bhphotovideo.com/c/product/4533-REG/Beseler_8022_39mm_Lensboard_with_5_8.html

If you want a handle on a flat board, you can find a suitable handle at a hardware store and attach it to the bottom surface of the board, Be sure to mount it away from front edge of the board where it must move forward about 2 mm or so under the front retaining plate.

Great info, thanks again.

 

[winger]

I use the same board for both my 50mm and 80mm and haven't had any issues grabbing the lenses (carefully) to take it out. I found it easier than trying to find a good way to store the unused one still attached to the board. This way, I can keep them in their respective protective containers when not in use (both lenses were bought new).

FWIW, you're still going to need to grab the lens to switch them even if they're on different boards.