Re: Determining SPT with gum Was: Gums a la Demachy and Puyo

From: David & Jan Harris <david.j.harris2_at_ntlworld.com>
Date: Fri, 14 Jul 2006 13:17:56 +0100
Message-id: <001a01c6a73f$9080dba0$6401a8c0@sotera>

Don, Terry, etc

It might be worth clarifying that the concept of a standard printing time (SPT) when using digital negatives is relevant to most processes and even to tri-colour gum and single coat gum, but the relevance to multiple coat, single colour gum (is there a better one word term for this?) is somewhat less. For this, it is relevant to the first layer only (after which, presumably shorter printing times will be used).

Both Katherine and Chris practise tri-colour gum, I believe.

David

----- Original Message -----
  From: TERRYAKING@aol.com
  To: alt-photo-process-l@usask.ca
  Sent: Friday, July 14, 2006 7:00 AM
  Subject: Re: Determining SPT with gum Was: Gums a la Demachy and Puyo

  In a message dated 13/07/2006 21:52:13 GMT Daylight Time, dstevenbryant@mindspring.com writes:

            Terry,

      

    What Chris and Loris are discussing is the calibration steps of printing gum using digital negatives. Once the minimum exposure time is determined it needs to remain constant through out the calibration process and is used when making negatives for prints. The image is altered via Photo Shop not by changing the exposure times when printing an image.

      

    Don Bryant

      

  Don

  Why ?

  Terry
Received on 07/14/06-06:18:47 AM Z

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