[alt-photo] Re: gum curve question

[henk thijs]

Don, Paul et al,
It is as if i hear my wife complaining about my missing ability to explain things using the PC ...
I try again.
Since years now i am making digital negs on Epson 1290 and Epson 3800 using a gum curve based upon a.o. PDN system .
This means that i take care of the UV-blocking of the used inks in the Epson-printers.
But , cleaning out my darkroom I found still a lot of  Arista APHS film and want to use the stuff.
So, like Paul said , I have to use an inter positive, sandwich the positive with the APHS film, expose, develop, fix , wash etc. (This positive is made like the digital PDN-based negative : via Photoshop digitally with Epson printers.)
The question is , what about the gum-curve , the UV-blocking does not play a role here, on the other hand the inter positive is made via an inkjetprinter with most probably also a different 'blocking' to 'normal' light, or?
Hope i made myself a bit more clear.
Henk


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www.thijs-foto.com
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On 18 aug 2010, at 22:35, Paul Viapiano wrote:

> Don,
> 
> I'm guessing that Henk wants to make a digital interpos to print on to APHS film to make a final neg, thereby eliminating the need to make a wet-step positive.
> 
> Henk, you could always try this and see what happens. Usually an interpos is made with much less contrast, so that final contrast can be controlled in the making of the interneg. You're looking to make color seps for tricolor this way, right?
> 
> Paul
> 
> 
> 
> 
> ----- Original Message ----- From: "Don Bryant" <donsbryant at gmail.com>
> To: <alt-photo-process-list at lists.altphotolist.org>
> Sent: Wednesday, August 18, 2010 12:03 PM
> Subject: [alt-photo] Re: gum curve question
> 
> 
>> Henk,
>> 
>>> 
>> Dear List,
>> Using the gum-curve via PDN to create digital negatives, the following
>> question came up:
>> Cleaning 'old-analogue-stuff' i found still a lot of Arista APHS film, so i
>> want to use it.
>> Making a digital positive and sandwich it with the APHS.
>> Now i was wondering about what curve to use: the one found with PDN making
>> digital negs is based upon UV-blocking of the ink used by the printer, but
>> for the sandwich 'normal' light is used to obtain the neg.
>> The question is what curve is to be used for the positive?
>> Now i tried the following : invert the positive, apply my 'PDN' curve,
>> invert again, sandwich and the result is a APHS negative.
>> Gum looks ok, but before going in tri-color printing i am open for any
>> suggestions :-)
>> regards
>> 
>>> 
>> 
>> 
>> 
>> I don't know about everyone else but I'm confused as hell about what you are
>> attempting to accomplish or do. Can you run this by us one more time with a
>> bit more clarity?
>> 
>> 
>> 
>> So sorry to be so dense,
>> 
>> 
>> 
>> Don Bryant
>> 
>> 
>> 
>> 
>> 
>> 
>> 
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