point light source?

[eli griggs]

In the earlier thread, “DYI Vacuum Easel Adventure” adapting a condenser enlarger for point light source was briefly discussed. I have a Durst 600 I would like to convert over to this method but the light source is not mounted above the condenser. Is an overhead position an absolute necessitate?

Where are the socket adapters for the auto bulbs to be found?

How about bulb choices?

Are certain type film/developers or papers more suitable for this type work?

I would also like to hear a bit more on the subject in general.

Cheers

 

[Poptart]

The Durst probably uses a mixing chamber which would automatically difuse the bulb's light rays. You'd have to have a point light assembly made that moves the light to the condenser stage. Alternatively, go to fineartphotosuppy.com and check out the cold lights; they'll custom make one if you need it.
Point light is very contrasty and sharp. Unfortunately, you'll also get every dust particle and tiny particulate and negative scratch, smear, pinhole, etc in perfect reproduction--i.e., endless print spotting.

 

[kbg32]

Hmmm, I remember a photographer Grant Mudford, back in the late 70s early 80s, who used a point light source for making his prints. They were exquisite, large, and grainy. I believe he shoots only color now.

 

[Poptart]

David Scharf's scanning electron microscope images were also printed that way, I think.

 

[djon]

I did it with several enlargers including a Durst 609...wmight work as well with a 606...I don't know the 600. Would work with Omegas and Beselers and perhaps Opemus.
the lamp does need to be located directly above the condensers...
the lamp is an automotive dome lamp or turn signal lamp, doesn't matter..
the socket can be an automotive socket...wrecking yard or perhaps car parts...
the lamp is 12 V direct current (like your car) so you need a transformer to convert your mains AC to DC 12 V...
the easiest way to do that is with a toy train transformer...I used a Lionel...the trains also run on 12V...
Spotting isn't that bad if you produce normally clean film and don't mangle it in handling...
Focus is critical, fussy.
You use the enlarger lens at full aperture, not stopped down...much sharper than your lens will produce any other way. Diaphragm blades damage sharpness, which is why highest resolution copy or process camera lenses use pinholes, not diaphragms.
It's fun! But you'll learn the limits of your processing habits as well as the limits of your camera lens.

 

[eli griggs]

Thanks for the info. The Durst 600 does not seem to be a good candidate for this method. I guess I'll just file this away for a future project.

Cheers

 

[Poptart]

You'd have better results with a cold light anyway.

 

[djon]

You wouldn't have "better results" with a cold light enlarger you'd have different results, softer results, smoother results, less sharp results. Those aren't good aesthetic results unless they're what you like. People use/d point source to get a specific incredible sharpness and reality...not routine stuff.

 

[Poptart]

I repeat: better results. Finer, wider contrast range and better separation in the highlights. Less spotting and retouching. No visible difference in sharpness. Easier printmaking. Better.

 

[djon]

Used properly, point sources are profoundly sharper than conventional sources (condenser, diffuser, cold light), and dust spotting's not a problem when film's handled reasonably well.
Focus does become much more critical than with other sources, which is a challenge to many enlargers. Old Dursts are particularly good for point source use because they have superior focus racks and superior negative carriers.

Every enlarging lens is sharper with a point source than it is with any other source, a simple matter of physics.

Using soft light sources to deal with dust is understandable, but not necessarily the best strategy for visual results.

Cold light sources excel at separating tones, are competitive with condensers but not anywhere near good point light enlargers for sharpness. To each his own.

Diffusion/cold light is often a better bet... babies, rocks/trees, kittykats, nudes. Point sources with good lenses, used properly, contribute when ultimate sharpness and a remarkable sense of luminance is interesting to the photographer.