I was fixing a Hansa enlarger over the weekend that I picked up in an as is state as part of a way cheap lot. There was poor light output with it.
The lamp house cover was taken off to have a look under the hood. It was apparent that the bulb, a 75W unit like in Omega's I have seen, was not clipped into its mounting position. I made up a new clip with some copper wire, and now the light bulb sits so 100% of its beam goes into the optical path, as oppused to about 30%.
It was still dim. Pulled the mixing chamber to see what the diffusing media looked like. All was still clean and white, but a mirror box used to turn light from the lamp after the filters into the box had only ever been friction fitted, and it had slipped low. Pull tape on the back of the enlarger, and there were two screw holes that lined up with tapped holees in the mirror box assembly. Two salvagesd small screws later, and the mirror assembly was mechanically held in proper alignment.
While the hood was off, I looked at the filters. All looked good and clean, but the Y one was stuck into the optical path about 8% even with its dial at zero when the filter lift lever was slid from white to colour. Minor disassebly ensued, and a linkage was carefully bent to allow the yellow to fully clear with its dial at zero. As a part of this investigation, I found that the filters fully engaged in the light path by the time the dial was turned to 120, despite being able to turn all the way to 170. I guess the cam designer was not fully conversant with the filter lever designer to match their system values properly some 30 or more years ago when this thing was being designed.
After re-assembly things were looking good.
To calibrate the thing a bit better for printing with MG B&W paper, since it now is know to have wierd filter settings, I sat its light path under my Lici 3000 colorstar analyser.
On white setting I would stick an Ilford MG filter in the neg carrier, and then fiddle with the analyser programming on an idle channel to null the display. I would then pull the llford MG filter, and use Y and M dials to match the colur the MG fiter made. I did this for filters from 00 to 5, and now have a table to start with to do a real calibration tonight printing step wedges onto MGIV to see how many steps I actually get for each of these settings.
I really bought the lot this enlarger was in to get the old paper boxes, which included the papers that I started out printing on over 25 years ago.
This enlarger once tuned in, will form the nucleus of a collection of surplus to me bits that I can set up in the laundry room on top of the washer and dryer to teach interested people how to do their first b&w printing. I have found that I have so much stuff crammed into my normal darkroom that it scares them off that they could ever pick up this craft if I introduce them to it in there.
By doing it bare bones, it is simplified, and if a person expresses an interest, I make a deal to sell/mostly give them all to get started from an old camera to the enlarger, chemisrty, film, paper and bottles, trays etc. to get them started. I have done this once now, and want to have a rig to be able to offer this agian.
The other cool thing with this particular enlarger is that this enlarger bulb is 12V, so it is feasible to run it in a set up on the road in a remote location powered from an automotive source. Looks like it is time to start looking for compatible 12V bulbs for a safe light.