Dimmer for Aristo VCL 4500 ?

**Jim Billlups** · 16-May-2001, 23:30

I am considering adapting an Aristo VCL 4500 cold light head on my Beseler 45mx enlarger. I will be printing mostly 4x5 negs with a 150mm lens. For those of you who have a similar set up, did you find it necessary to purchas e and use the optional dimmer control available through Aristo? Also, what are s ome of your typical exposure times for 11x14 and 16x20 prints?

Thanks,

**Robert A. Zeichner** · 17-May-2001, 07:51

I don't have the dimmer and don't know that I need one. Exposure time will of course depend on how dense your negative is and what aperture you prefer to project through. At f8, with my El-Nikor 150mm lens, I typically have exposures from between 12 to 30 seconds for a 16x20. I use a 105mm for my 6x6cm negs and at f8 usually find myself exposing for 6-20 seconds. I hope this helps. You'll love this light source!

**Sandy Sorlien** · 17-May-2001, 10:28

Hi Jim, I have a 4500 VCL on a Beseler 23C so can only give times for medium format negs. You'll find that the higher the contrast you dial in, the shorter the exposure times (opposite of using filters). In general I was alarmed at the slowness of the light at first, but the Aristo guy reminded me to compare times to using filters, which makes it much less alarming. I had gone to this head from using a straight cold light head with graded papers, generally much faster. I am not aware of the dimmer switch, so I guess I don't have one. The control console for the head has plenty of adjustments, blue light only for super high contrast, green only, green/blue adjustable. It is easy to do split printing with the blue only for part of the exposure to get above number 5 (not the same as a grade 5 filter). The blue only is extremely dim, good luck seeing where to burn & dodge. But I rarely use that. The blue/green is bright enough to see. I would say at f/8 (3 stops down) for 16x20s with 4.5-5 contrast, I'm printing in the 30-90 second range. Many of my negs are dense (from plastic camera). After five years I do really like this head. Cheers.

**kthompson** · 17-May-2001, 15:40

Jim, I've been using the VCL 4500 in my home darkroom for over 5 years, and I haven't found a need for the dimmer switch. I did have the Aristo head that was just the blue tube (5x7 size) with the filter holder and dimmer switch. Sorry, I don't remember it's model #, but I used the dimmer switch on that from time to time, when I had thin negs or whatever and wanted to standardize on a certain f-stop. You can still do this with the VCL unit, but only on the blue tube. As as I know though, Aristo can rig up just about any custom arrangement you want on these heads, including adding a third tube for color. I sent my old unit back to them and they upgraded it to the 2 tube head. It's a great system though, and with a timer like the Metrolux, you can have a closed-loop production type enlarger easily. The 2 tubes are perfect for split filtered printing, and tweaking contrast. I print everything from really old nitrate rollfilm negs, half frame 35, straight through 4x5 on it & it's really nice...