[alt-photo] Re: humidity and contrast in the palladium / platinumprocesses

[Jeremy Moore]

Good point on the sheeting, Paul. If you one doesn't have mylar or something
similar you can even cut down a plastic trash bag to fit. Anything that will
keep the moisture in during exposure will work for this test.

On Fri, May 21, 2010 at 10:11 AM, Paul Viapiano <viapiano at pacbell.net>wrote:

> If you're in a dry climate or using a vacuum frame, try placing a large
> sheet of mylar/thin plastic sheet on the bed and then placing your neg/paper
> sandwich on top of that (after Jeremy's post-coating pre-exposure
> humidification). This will keep the paper from drying out during exposure
> and result in better dMax...
>
> Yes, old FO can give you anemic prints. B&S' ferric is said to last 1-2
> years in solution but many factors, of course, can alter that. Many
> professional printers mix FO the night before a printing session and FO is
> available in premeasured mix packs for that purpose.
>
> Paul
>
>
>
> ----- Original Message ----- From: "Jeremy Moore" <jeremydmoore at gmail.com>
> To: "The alternative photographic processes mailing list" <
> alt-photo-process-list at lists.altphotolist.org>
> Sent: Friday, May 21, 2010 7:59 AM
> Subject: [alt-photo] Re: humidity and contrast in the palladium /
> platinumprocesses
>
>
>
>  Francis,
>>
>> I will suggest a very easy test to see how relative humidity affects YOUR
>> printing.
>>
>> Variable: Humidity
>>
>> Experimental Model:
>> 1. Coat a piece of paper and immediately blow dry it (preferably with cool
>> air so as not to introduce another variable, but you do want forced air)
>> then expose it.
>> 2. Process as normal.
>> 3. Coat a 2nd sheet of paper and immediately blow dry it (dry it in the
>> same
>> manner as you dried the first one). Re-humidify this paper by holding it
>> over steamy water from a tap or heated water on a stove or a humidifier if
>> you have one. Humidify the paper until it is as damp as you think you can
>> make it without ruining your digital negative then expose it.
>> 4. Process as normal.
>> 5. Let both prints fully dry then compare and report back to us!
>>
>> Notes: Keep everything as constant as possible--even to the point of paper
>> from the same batch or coating 2 halves of the same sheet. Print an image
>> with long, smooth tonal scale. Include a step wedge in the prints--both a
>> Stouffer if you have one and a test wedge created in Photoshop that is
>> part
>> of your digital negative.
>>
>> On Fri, May 21, 2010 at 9:49 AM, francis schanberger <frangst at gmail.com
>> >wrote:
>>
>>  Dear AltList,
>>>
>>> What is the working relationship of relative humidity to the final
>>> contrast
>>> in either a palladium developing out print or a printing out print?
>>>
>>> I've been struggling with contrast and have always been rather
>>> laissez-faire
>>> in monitoring and adjusting humidity due to the dungeon like qualities of
>>> my
>>> dim room.
>>>
>>> In regards to developers, does ammonium citrate ever get too old? Could a
>>> trend of producing low contrast images independent of drop mixtures
>>> indicate
>>> exhausted developer? I was reading in the Weese / Sullivan "New Platinum
>>> Print" book that older ferric oxalate tends to have higher not lower
>>> contrast.
>>>
>>> -francis
>>>
>>>
>>>
>>>
>>> --
>>> francis schanberger
>>>
>>> www.frangst.com
>>> _______________________________________________
>>> Alt-photo-process-list | http://altphotolist.org/listinfo
>>>
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