This is going to sound like an ignorant question, but here goes!

How do I know if my enlarger's head is "cold light"? It's a Durst M805 with a colour head.

-- Ed Hurst (BullMoo@hotmail.com), December 05, 2001

Answers

Typically, a color head is a diffused light source and not a cold light. A cold light head is a tightly wound flouro bulb putting out a cold tone cast. You can look at your bulb in your head. If it is a "projection bulb" it is a point light source that is dumped into a diffusion box. It will make your retouching easier but it will not have the same look as a cold light. Also, I don't think a cold light is made for a color head. Cheers

-- Scott Walton (scotlynn@shore.net), December 05, 2001.

Ed, There seems to be a bit of confusion out there about light sources. Actually, there are two different sets of characteristics to be considered here. First, is the light source "hot" or "cold". This only refers to whether or not the light source is incandescent (halogen or tungsten bulb) and therefore "hot", or flourescent, and therefore, "cold". The other thing to consider is the collimation of the light itself. This divides itself up between the poles of point sources with condensers, which are very collimated (i.e. the rays all in a line, roughly parallel to each other) and the various diffuse light sources, in which the light rays are more or less scattered. Many printers prefer one or the other. A lot of time and talk has been devoted to the advantages of diffuse sources, the catagory which cold light heads and hot color heads with mixing chambers belong to. I'm sure you are acquainted with the rhetoric. At any rate, to answer your question (although I'm not familiar with the Durst head): If your light source is tungsten or halogen, you have a hot light. If there is a mixing chamber in your color head, as I suspect there is, you have a diffuse source which will give equivalent results to a cold light head. Hope this helps. ;^D)

-- Doremus Scudder (ScudderLandreth@compuserve.com), December 05, 2001.