Aristo cold light fast print times

[Andy_1233]

I recently upgraded my old Beseler MCRX with an Aristo cold light head with V-54 lamp. Very powerful. To get a reasonable printing time (around 14-18 sec.) I ne ed to stop down to f/45! Has anybody else experienced this? The lamp is 70W, for the D2 with the Beseler adapter.

The most obvious approach to the problem is to add a ND filter but being one mor e surface to keep scratch and dust free I'm not to thrilled with that idea. I fi nd that Aristo makes a dimmer for the cold light but that's an additional $90 an d nobody seems to have it in stock.

My old Beseler has the 'resistrol' dimmer on it for the condensor head, however this is more like a typical resistance type dimmer for incandescent lights and d on't think it will work or may damage a flourescent type light like the Aristo. Can anybody verify this? Or offer a more economical alternative to the Aristo di mmer?

I'll probably call Aristo on Monday but I was all charged up to do some printing this weekend! On the other hand, I can expose Azo at 2-3 minutes;)

Thanks as always!

[Gudmundur Ingolfsson]

Try a thicker sheet of plexiglass under the lamp.

[Will Ewing]

I had exactly the same problem with my coldlight upgrade. I did call them and was told that you can use an old auto-transformer like the old Variac or even a solid state dimmer. The deal is that you will only get about three stops of control. I tried this and it does the job ( I am using a variac because I had it) and seems to work to about 65% of the line voltage. After that the lamp quits. I asked if this hurts the lamp and was told that because of the low duty cycle it is not an issue. I have not tried the solid state dimmer. They offer a solid state dimmer for sale, but I have no idea if it is really any different than a regular lamp dimmer. I suspect that a "cheapo" dimmer would work, but I would be concerned that the intensity would be bright at turn on and settle to a lower value. But for the price, it might be worth a shot. Good luck!

Will

[jnantz]

hi andy i had the same problem, and more so since i opted for the "hi" or "high output" lamp .. i ended up buying the dimmer right from aristo. you might give them a call and ask for rick. he will be able to help you if you have any technical issues or if you want to buy a dimmer, he will sell you one right over the phone. i have been using the dimmer for a few months now and i am really glad i got it ... good luck! - john

[Dave Schneidr]

I had the same problem and opted for the Aristo Dimmer. The thing I didn't like about the dimmer was that it was hard to keep exposures repeatable if you had to return to full brightness to check focusing. The switch on the Aristo dimmer simply turns the light off. I rewired the switch so that the dimmer is is switched in and out of the circuit. I can set the dimmer where I need and thes with the switch return to full brightness. I also calibrated the dial in 1 stop increments, I think I got a four stop range.