coldlight headgreenspun.com : LUSENET : Large format photography : One Thread
Are replacement bulbs available for the Aristo and Omega coldlight heads? Can you use VC filters with these units, or must you use different paper grades? Is there any thing other than the bulb that may break on one of these heads?
-- Tim Kimbler (firstname.lastname@example.org), November 17, 1998
With older cold light heads, you get different contrast with different filters, but the "real" contrast doesn't match the number on the filter. Aristo's new bulb...the V-54...works much better. You can buy one directly from Aristo...I think they cost about $100. They have a web site. I just called them on the phone, and they were very helpful. Sent the new bulb right out to me. I get much more even contrast change with the filters now.
-- John Sarsgard (Endive4U@aol.com), November 19, 1998.
The latest tube V-54 for the Arista can probably be purchased at B&H Photo for less $. Be aware that VC papers do not respond as 1 to 1 to graded papers with cold light. Howard Bond has written articles about establishing correct correlationships to graded numbers.
-- George Nedleman (email@example.com), November 19, 1998.
For years, I used an Aristo head with the standard blue lamp which is optimized for graded papers. As time went on I found myself using VC papers more and more and I really didn't have any problem getting a wide range of contrasts using filters with the graded lamp. Recently, however, I switched to the V54 lamp and I am very happy with the even contrast spacing I now get. I have yet to find out how graded papers will work with the V54 lamp. I suspect that the only difference would be, maybe, slightly longer printing times, all else equal.
In response to the other part of your question: There really isn't anything else, that I know of, in the head to break except, perhaps, the heating element and the contact points. But I think that they will probably last virtually forever.
-- Tom Johnston (firstname.lastname@example.org), November 20, 1998.