U of S | Mailing List Archive | alt-photo-process-l | Re: Measuring DMAX

Re: Measuring DMAX

Title: Re: Measuring DMAX
Somewhere I have a device marketed by Kodak many years ago. This is a sheet of card, rather like a grey-card but printed with patches of different reflection density. Each patch has a hole in it, so you can place it over a print, find the matching density and read off the value. Fairly crude, but effective – not least because when you do the match, both the print and the reference are in the same illumination. Must be thirty years old, and if you give me a week or two I might even be able to find it!


On 14/1/08 21:30, "Dave S" <fotodave@dsoemarko.us> wrote:


You should be able to find a lot of information through internet. I remember seeing lots of articles on this when scanner was becoming popular.

I had/have both densitometer and scanner, so at one time (many many years ago) I tried it out, and the measurement using scanner is quite reasonable.




From: Marek Matusz [mailto:marekmatusz@hotmail.com]  
Sent: Monday, January 14, 2008 4:03 PM
To:  alt-photo-process-l@usask.ca
Subject: Measuring  DMAX

Is there a way to measure the DMAX of a print with a scanner  /Photoshop? I do not have a densitometer at hand. I vaguely remember a thread  a while back, but could not find it.

> Date: Sun, 13  Jan 2008 10:06:14 -0500
> From: sanking@clemson.edu
> Subject: Re:  Fresson question
> To: alt-photo-process-l@usask.ca
>  Reflective D-Max is just a term that describes the darkness of a
>  print as measured with a densitometer, so it is expressed as a log
>  value. Pt./Pd., kallitype and vandyke prints on art papers generally
>  have a maximum Dmax of about log 1.45 - 1.55. Silver prints on glossy
>  papers can have a Dmax of up to log 2.2 or even higher. A direct
>  carbon print like a Fresson print will have a maximum Dmax of below
>  log 1.4. Carbon transfer prints can have a reflective Dmax as high as
>  silver papers, though this depends on many working conditions.
> Reflective D-Max is a technical description and does not make any  
> implication about aesthetic quality, though many pursue it for its  
> own sake as they do detail and sharpness.
>  Sandy
> At 12:25  AM -0500 1/12/08, Judy Seigel wrote:
> >
> >
>  >Now, however, a possibly dumb question... though I doubt anyone's
>  >reading this far, so what the hey: What is "reflective D-Max"?
>  >D-max on an opaque surface rather than in a transparency? Or?
>  >(I've never seen that term -- tho, just ask me & I'll explain  ULF.)
> >
> >
> >
> >Judy


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