[Alt-photo] Re: Mechanism for Platinum Enlargements

[Francesco Fragomeni]

Don and Peter,

Thanks for chiming in! Sorry for the delay in response. The work week has
been insane.  Anyway, the mirror idea sounds interesting. As does the idea
about trying to find one of the Durst units. From what I understand the Azo
enlarger was really just a Durst enlarger with the high powered 5kw head. I
wonder how difficult it would be to get a hold of one of those heads. I'm
also curious what the power requirement would be. I live in NYC so running
a dedicated power source isn't really not a possibility.

I've also seen mentioned a number of times that people have had success
enlarging on Azo (and feasibly pt/pl) using a regular color head. I'm
assuming that their making use of a blue setting. It's strange, I've seen
this mentioned but no one really seems to describe it in detail at all. I
also have an actinic cold light back in phoenix which could yield a similar
result. I'm unsure when Id be back there an able to test this.

Another question that comes up is the difference in negatives that would be
required. I'm used to working with a denser and contrastier neg for contact
printing pt/pl. I wonder how this would change when projection becomes a
part of the equation. Ideas here?

My darkroom in NYC is small and set up for contact printing so I have no
enlarger. Maybe I'll have that cold light shipped out and rig an enlarger
out of a spare view camera to see what I can get to work.

Any more thoughts or ideas on this topic?


On Tue, Nov 5, 2013 at 11:02 PM, Peter Friedrichsen <
pfriedrichsen at sympatico.ca> wrote:

> The ferric oxalate light sensitivity is still very good up to about 520nm
> (throughout the blue light range) so maybe the Durst Azo unit, which I see
> uses quartz halogen, could do the job. Perhaps you could find one to test.
>
> Peter Friedrichsen
>
>
>
> At 12:40 PM 05/11/2013, you wrote:
>
>> Hi All,
>>
>> I may have asking something along these lines a long while back but I'm
>> unsure. There also may have been a bit of conversations around this
>> on-list
>> in the past. Anyway, I've always been fascinated with the old methods for
>> making Platinum enlargements and I'm curious if anyone knows any of the
>> numbers (exposure times) or knows of anyone who's working (albeit slowly)
>> with anything like this now.
>>
>> Despite common belief, making platinum prints through an enlarger is
>> indeed
>> possible and there is a long history of this. As a quick recap, the most
>> common method was through the use of a solar enlarger attached to a
>> heliostat. The solar enlarger was essentially the same as a modern
>> enlarger, most commonly using condenser lenses but there is documentation
>> discussing diffusion solar enlargers as well, and lenses that were good at
>> passing UV light. The heliostat was a mechanism that allowed the enlarger
>> to track the movement of the sun subsequently keeping the light source
>> centered and focused throughout the printing.
>>
>> Much later Durst made a UV enlarger for Azo and supposedly had one in
>> development for platinum printing but it never made it into production.
>>
>> Anyway, I've heard whisperings of people who's made platinum enlargements
>> essentially in conventional enlargers after replacing the lens with an
>> older lens that'll pass uv light (modern lenses tend to block uv) but I
>> can't really find any documentation of this. What I've heard is that the
>> super powered lamps as used in the Durst UV enlarger (5kw and requiring
>> serious cooling) are not actually necessary if you're ok with loooong
>> exposure times (into hours). The Durst was supposedly designed to make
>> these exposures both possible and relatively quick. I personally wouldn't
>> care if the exposure times were very long if this is something that could
>> actually be achieved.
>>
>> Does anyone have any information/experience with this? Any idea of how
>> long
>> exposure times would actually be if using a uv bulb or mercury bulb in a
>> diffusion or condenser enlarger?
>>
>> Lets try to keep this on topic. This isn't intended as an opening for
>> recommendations to contact print or make enlarged negatives. This topic
>> isn't concerned with any alternatives. We're all aware that platinum
>> prints
>> are conventionally made using contact printing. We also know about making
>> enlarged negs. No need to touch on any of that here. This is about the
>> feasibility, practicality, and possibility of making a platinum
>> enlargement
>> via an enlarger set up to utilize uv light. We're also not tied to
>> attempting to attain short exposure times here. Long is fine. I'm
>> interested in tapping into the creative thinking of those on-list so lets
>> try to limit the "thats impossible" talk. We already know that platinum
>> enlargements are possible. Thoughts?
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