Cold light head for beseler 23c question

Hey all,

Im looking into purchasing a cold light head for my beseler 23c, Ive found one in good condition for a good price, but I just read that you lose the ability to use variable contrast papers with a cold light head on the 23c? Also, I read that the type of timer should be taken into consideration as well. I have a gralab 451 timer for my 23c

I had assumed that I could just install the head on 23c and be ready to go.

I suppose it may be easier to ask what I need to do to switch the light source on my beselar 23c to a cold light?

Can someone point me in the right direction here? Any thoughts or a link to a previous discussion here would be mighty helpful.

Cheers,
Mike

Older coldlights had a tube with an abundance of blue light. This made them fast for graded papers, but when using VC papers, the VC filters did not provide the grade indicated on the filter. You can correct this by adding a yellow filter under the coldlight, and then use the VC filters. Newer coldlights use the V54 tube, which works much better for VC papers. The label on the outside of the coldlight should indicate which tube it uses.

Coldlights have a high inductive load on startup. Mechanical timers usually handle this without problems, but some electronic timers may have problems. Gralab and Aristo, and others, make a “contactor” or relay to handle coldlight loads. Check with Gralab—you may not need this contactor.

Another great resource is Aristo themselves. Ask For Rick Mehta, an engineer there. You have to be persistent to get him, but he's helpful. He can answer all technical questions, primarily about the timer. The above thread is correct about the V54 lamp, which Rick will verify. (203) 578-4600 is their number (the last time I called).

My phone number for Aristo is 203-575-3425.

Thanks for the info guys, Ill give em' a call on monday.

Cheers,
Mike

Also to mount the cold light on the 23c you need to use the condenser housing. The condensers are removed and the cold light put in the housing. It's easier to get a separate housing for the cold light especially if you plan to switch back and forth. For filters you can use the type that mount under the lens. Most people say they cause no problems if kept clean.

Mike... One thought to add on this. I used an Aristo for years on a 23CII and functioned fine with the filter drawer. The one irritation I found was that the upper bellows/light box needed to be compressed very firmly onto the negative stage to not vignette on 6X7 negatives. I switched to a Dichro a few years back and find that I don't struggle with this issue anymore. The overall results are very similar and the lack of spotting is pretty much the same, too.