I just began a position as a studio associate in the art department of a small liberal arts college near Chicago. The photography professor and I are working together to try to perform routine maintenance on about ten Beseler 23cII and 23cIII enlargers in the darkroom.

Neither he nor I have ever performed this maintenance before, because historically the school would pay a technician to come in and do a routine tune-up on them every once-in-a-while. Enrollment in film photography classes has dropped some, though, and maintenance of these enlargers has been overlooked for a few years. Now we're calling around trying to find a technician to service them for us, but everyone who used to do it has either retired or discontinued that service, so we're trying to do it ourselves. We have some gaps in our knowledge, though, and we're hoping someone can help us learn the tools and best practices for maintaining these machines.

Here's what we (think we) know, followed by a few specific questions.

From the manual, I read that maintenance should include the following:

A - Lamp Replacement
B - Condenser Cleaning
C - Lubrication
D - Gear Replacement
E - Elevation lock replacement
F - The alignment should be checked and adjusted

Here are my questions:

1 - Is this a complete list?

2 - The photo professor seems to remember the technicians using some kind of vacuum to remove dust from inside the enlarger. Is this a thing? and if so, what kind of vacuum or tool is used for this?

3 - If anyone has serviced these machines before, do you have any tips or warnings about any of these procedures?

4 - Do you know anyone in the Chicago area who still does service visits on enlargers?

Thanks for your help!


  • \$\begingroup\$ From experience of computer maintenance I would guess it was a compressed air canister rather than a vacuum cleaner. \$\endgroup\$ Commented Sep 22, 2019 at 8:37
  • \$\begingroup\$ Thanks everyone for your help! I went ahead and tackled this project last week. I feel like it went well and, like Alan Marcus said, it wasn't rocket science. I am going to see about Wolf's suggestion and test the timers and sharpness. Thanks again! When I'm done, I'm thinking of throwing together a PDF listing the steps in the process with photos (I couldn't find a tutorial online when I was trying to figure this out, and I think it would be nice to make one available). Does anyone have any suggestions about where to post such a thing? -Sheldon \$\endgroup\$ Commented Sep 23, 2019 at 14:33
  • \$\begingroup\$ Wikihow would seem a plausible option. \$\endgroup\$ Commented Sep 23, 2019 at 19:45
  • \$\begingroup\$ @SheldonTill-Campbell You could post a step by step here as an answer to your own question. That would a) answer someone who has a similar question and b) allow edits and improvements from the community. \$\endgroup\$ Commented Dec 10, 2019 at 8:34

4 Answers 4


Here's what I'd do:

Take it apart and blow it out with dry compressed air

use specific bulb designed for enlarging if you change bulbs

clean the condensor (s) with lintless wipes and use lens cleaner

spray some wd-40 on a rag and wipe the gears and tracks with it, use very lightly and sparingly

If the elevation lock is broken fix/replace it... duhhh!

Now here is the really important part. Get or make a sharp test negative to project onto the paper surface. Make sure it is sharp edge to edge, make a print and check it. The negative is like a test-pattern with lines and numbers on it. If it is not sharp, something will have to be 'adjusted' to make it all level.

What is not on the list and is also important is remove and clean the enlarging lens

Might also check the timer for accuracy or at least check all the timers against each other

  • \$\begingroup\$ There is no sharper test image than the edge of thin metal foil. \$\endgroup\$
    – Stan
    Commented Mar 7, 2020 at 15:08

Most of it is common sense. I am a maniac, so let me categorize things. Maintenance, in general, is divided into two categories.

1. Preventive

  • Cleaning

  • Lubrication

2. Corrective

  • Parts replacement

  • Oxidation

  • Electric malfunction

  • Light leak

The first part is to actually know the stuff. So take a screwdriver, on a clean desk and try to disassemble some parts.

An enlarger is a sturdy case, you could actually want to see if there is hard dust accumulated inside, or see if there is some paint chipped or even oxidation away from the inside. You probably need to use a brush instead of just compressed air, and if there is oxidation, you need to sand it and use black matt paint, use light layers of spray.

As with any screws, be gentle with them so you do not break them or sweep the helix.

Remove the glass elements, lens, and condenser, but I would not use any water-based chemical. I prefer using a microfiber cloth (in case the lens has no coatings). If it has only dust use a gentle brush. Only if it has stains, use a cleaner but keep it away from metal. I would use dishes of soap and water for the condenser (If it is glass only) and some specialized alcohol-based lens cleaner for the lens. Do not use water-based ones, you do not want to initiate some rusting.

See if the bellows are not too dry and have no light leak. Thos would be the most complicated part to fix. Probably needs to be patched with some dark fabric glued with a flexible glue. (Any additional tip here is accepted)

See if the lenses do not have any fungus inside. If it has dust or fungus, you probably need to either disassemble it or send it to a repair shop.

You can probably upgrade the lamps to some led based ones to make the enlargers safer keeping them cooler. You need to make tests for uniformity of light and output power. You would need to make a test to see if it works with the color filters.

I do not know if the filters will still work and they are fungus free. If you only use the enlargers for black and white the color temperature is not that important. For black and white, you can use a cool or warm color. If you want to use it for color prints, probably need a warm-toned led (simulating an incandescent lamp) and see if it works.

As you can see it is only common sense.


A lot of good info there. Please feel free to ask me about service. I am on Long Island so geographically you are far but I will answer any question. Lamp wise, led not really needed as the 75 watt usual is not that hot. I have seen many 23c 111 with no heat shield at all and no cooked negs. Alignment with a laser is fairly easy with practice. Or a parallel mirror can be used also. One must align the carrier stage and the lens. The handle and cams for opening the neg carrier stage usually need adjusting as the roll pin or Allen set screws can get out of whack. The focus portion usually needs some attention. As to filters in b/w, if you mean poly contrast, surely avoid fungus. Only clean condensers if you must as the units are usually fairly clean inside. If you move things around then be sure the light image on the base has no hot spots. That's enough for now. Have confidence. M Addendum re: condenser cleaning. I have cleaned a few that were outright black. Due to the chimney effect, room dust will always be drawn upward from bottom to top. I suppose as a person new to this work, the enlarger mom in me got over protective. You can do it but only with a safe soft bench under the assembly in case of dropping. One more thing, it’s a good practice to stop down the lens to the middle at least because a pattern test often reveals an elevated center temp. If you use a pattern and expose the image on an 8by 10, both wide open and say f 8 you may notice some darkness towards the center. [email protected]

  • \$\begingroup\$ Parallel mirror? Did you mean a first-surface mirror? Optical alignment using a laser beam is referred to as collimation. \$\endgroup\$
    – Stan
    Commented Mar 7, 2020 at 15:06

Not rocket science -- most any building maintenance man / electrician will get the hang of it in a heart beat. Clean condensers with Windex.

  • \$\begingroup\$ Or indeed building maintenance woman? \$\endgroup\$
    – osullic
    Commented Aug 22, 2019 at 7:51
  • \$\begingroup\$ Thanks Alan (and osullic)! This gives me a bit more confidence to just go for it. \$\endgroup\$ Commented Aug 22, 2019 at 17:26
  • \$\begingroup\$ If the worker needs advise - [email protected] \$\endgroup\$ Commented Aug 22, 2019 at 18:46
  • \$\begingroup\$ Alan, is there any reason that advice needs to be private correspondence and can't be in your answer? \$\endgroup\$
    – mattdm
    Commented Sep 20, 2019 at 21:27
  • \$\begingroup\$ No reason, anything I say, any advise is public stuff. An electrician or handyman might need on-the-spot advise, I have helps others like this, I do this for free. \$\endgroup\$ Commented Sep 20, 2019 at 23:18

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