Re: [Largeformat] Converting a camera to an enlarger

["Pete Caluori" <pcaluori@hotmail.com>]

From: "Pete Caluori" <pcaluori@hotmail.com>

>From: Thomas Huettemann <huette@Mathematik.Uni-Bielefeld.DE>
>Hi everyone,
>
>we had this thread before ... I'm trying to use my camera as a
>(horizontal) enlarger. For illumination of the negative I built
>a wooden box with a lamp at the one end and a piece of frosted,
>opaque glass at the other end. I tried different kinds of light
>bulbs. One is a 150 W enlarger light bulb, which results in a
>somewhat low output of light. Another one is a standard 75 W halogen
>light bulb with built-in refelctor (the flood light type, not a
>spot !). This gives nice bright illumination of the negative.
>However, I have two major problems to solve:
>
>1. Heat. Especially with the reflector, the glass and the negative
>    get very hot with time.
>2. Uniformity of illumination. All types of bulbs I've tried so far
>    give a quite distinct fall-off towards the edges.
>

Hi Tom,

I think I have a solution to both of your problems.  While I’ve not actually 
done this, I have been thinking about this for some time. Rather than keep 
the light source, negative, lens and paper in a straight line, offset the 
light source 90 degrees.  You would have to build a light/mixing chamber.  
Something that was coated/painted bright white. I was thinking of using thin 
sheets of Styrofoam to line the inside of the light chamber, as this would 
help to diffuse the light even further.  I believe Omega made an enlarger 
that worked exactly this way.  Should heat remain a problem with the lamp in 
this configuration, a small muffin fan could be added to aid in cooling.

When I get the time (one of these years) I plan on trying this.  I was going 
to build the light chamber out of cardboard and/or masonite and/or wood and 
line the inside with thin sheets of white Styrofoam.  A thin piece of opaque 
Plexiglas would complete the light box and provide the final diffuse light.  
Good luck and let me know what you find.

Regards,  Pete