Re: [Largeformat] Converting a camera to an enlarger

[JIB <jbuf@ix.netcom.com>]

From: JIB <jbuf@ix.netcom.com>

You can try an exhaust fan to keep the heat inside the chamber down.  Just
be sure an mount the unit remotely.  Or the other thing you can try is using
a bigger bulb, it would make the exposures shorter, making the heat a non
issue.  the elwood 8x10 enlarger used a 300 watt bulb, but the lamp was
hugh.

Thanks
John

Thomas Huettemann wrote:

> 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.
>
> I'd really appreciate any hints and comments !
>
> Let me add a few comments: I know that some enlargers (e.g., Beseler)
> have built-in heat filters. Maybe one could get one of those ?!
> Or maybe adding another piece of (clear) glass might reduce the heat.
> As for a uniform light distribution, I added an opaque piece of plastics
> which yields an even light all over the negative, but the intensity
> is reduced too much. I might try a second (additional) piece of frosted
> glass mounted right in front of the light bulb.
> I'd really like to avoid the use of condensors, because I suspect that
> the lenses might be expensive and difficult to get.
>
>         Thomas Huettemann
>
>