Re: Dmax versus process?

Sandy,

I still find a 1.2 Dmax for a single coat gum print on the low side, it's
just a surprise for me and I wont pursue this anymore, promiss...

I check to make sure and effectively density values are dimensionless and
have no units, the way you wrote density values below made me think for a
minute you where talking about exposure scale or something similar.

Density = log10 ( Opacity) and Opacity is the ratioof light intensity
(in/out)

the ratio cancels out the units.

Regards
Yves

----- Original Message -----
From: "Sandy King" <sanking@clemson.edu>
To: <alt-photo-process-l@usask.ca>
Sent: Monday, May 01, 2006 12:07 PM
Subject: Re: Dmax versus process?

> My Lord, before this goes a step further please note that I did state
> that all of the processes were for single coating and exposure. With
> multiple coating you can indeed get much higher Dmax with gum. And
> maybe Chris can get Dmax of 1.8 or more in gum with full tonal scale
> using a digital negative.
>
>
> But that is what all of the fuss about coating from the back was
> about, i.e. the possibility of getting a higher Dmax with gum with
> just one coating and exposure.
>
> In my experience the only thing that poses greater danger to your
> health on this list than political commentary is getting misquoted
> about gum.
>
> Sandy
>
>
>
>
>
> >Sandy,
> >
> >thanks, your answer is much better then I expected. I'm surprised that
you
> >can't get a better Dmax from gum unless this is for a single coat of
course.
> >
> >I always thought that density measures where dimension less??
> >
> >Thanks again and my best regards
> >Yves
> >
> >PS Thanks to Loris as well.
> >
> >
> >
> >----- Original Message -----
> >From: "Sandy King" <sanking@clemson.edu>
> >To: <alt-photo-process-l@usask.ca>
> >Sent: Monday, May 01, 2006 11:32 AM
> >Subject: Re: Dmax versus process?
> >
> >
> >> Yves,
> >>
> >> I don't know if there is a text on this anywhere, but my own
> >> measurement of reflective Dmax of these type of prints suggests the
> >> following. This has been for prints with a full range of tones from
> >> the highlights to the shadows, and is for one coating and exposure.
> >>
> >> By process, the maximum Dmax that I have seen are.
> >> 1. Silver gelatin print on glossy paper -- log. 2.2 or higher.
> >> 2. Carbon prints on glossy papers -- log 2.0
> >> 3. Silver gelatin print on matte paper - log 1.85
> >> 4. Carbon prints on matte type surfaces - log 1.80
> >> 5. Albumen -- log 1.8
> >> 6. Pt./Pd. and kallitype -- log 1.55
> >> 7. VDB and Argyrotype -- 1.45
> >> 8. Salt Print -- 1.40
> >> 9. Gum prints -- 1.20
> >>
> >> Again, these numbers are based on readings that I have taken of
> >> actual prints, and will almost certainly differ to some extent from
> >> the experience of others. Also, toning plays an important role in
> >> Dmax of all types of silver prints.
> >>
> >> It might be interesting to gather more information on this with wider
> >> sampling, but for useful results it would have to be done in standard
> >> conditions and with calibrated equipment.
> >>
> >> Sandy
> >>
> >>
> >>
> >>
> >>
> >>
> >>
> >> >Hi,
> >> >
> >> >say you make several prints using the same paper, maybe a step tablet
to
> >> >keep it as simple as possible, what could one expect in terms print
Dmax
> >> >from various process like Salt prints, Kallitype, Vandyke,
Argyrotype,
> >> >Platinum, Palladium and pigment based process say gum and or carbon?
> >> >
> >> >If there is some text somewhere on this, it would be fine. I know
some of
> >> >you teach alt-process printing and I'm sure someone as an idea on
this,
> >it
> >> >doesn't have to be in absolute terms.
> >> >
> >> >Thanks
> >> >Yves
> >> >
> >> >PS. Please don't say try it out yourself...
Received on 05/01/06-01:11:11 PM Z