From: Sandy King (sanking@clemson.edu)
Date: 09/10/03-01:15:39 PM Z
Nick,
I don't know how to lower the contrast on the 1160. I would think
that the best thing would be to have a curve that would adjust the
image on screen to the correct printing density range.
As for the correct DR of a Pt/Pd negative, about 1.4 - 1.5 seems to
be in line with what most printers use for a combination of the two
metals, and about 1.65-75 for palladium alone.
To repeat, subtracting the least dens from the most dense areas of
the step wedge will suggest a slightly greater density range than
would be the case if you plotted a film curve from the negative, and
this is because some of the density would be toe and shoulder. So if
you read 2.1 by your method, the actual DR of the negative would
probably be around 1.8 or 1.9.
Sandy
>Keith, Sandy and all,
>
>If I understand and have done taken my readings correctly, the 1160
>neg I have been eluding recently has a DR of 2.15 and I can reduce
>that DR by simply changing the Media Type in the advanced printer
>options menu. Moreso, I believe the prints produced are better
>without any waxing or oiling.
>
>In reading through some of my archived posts, Keith suggests that DR
>2.1 is a good number for PT/PD - does anyone want to comment on that?
>
>My calculation was made as follows (someone please correct me if
>this is wrong):
>I took readings from the most dense and the least dense (not the
>base) areas and substracted to determine the range.
>
>I always new there was a way to use my analyzer as a densitometer -
>another use for an old tool.
>
>Many thanks again,
>
>Nick
>
>----- Original Message -----
>From: <mailto:sanking@clemson.edu>Sandy King
>To:
><mailto:alt-photo-process-l@skyway.usask.ca>alt-photo-process-l@skyway.usask.ca
>Sent: Wednesday, September 10, 2003 11:01 AM
>Subject: Re: DR vs. f-stops
>
>
>I am assuming you mean nine stops, and not nine steps of a 21 step
>transmission step wedge, because each of the steps of the wedge is
>log 0.15, or 1/2 stop.
>
>If the measured value is really nine stops the actual negative
>density range would be slightly less than 2.7 if you graphed it and
>made a curve because some of the density would consist of toe and
>shoulder. But your calculation is generally on target, 9 stops X log
>0.30 = 2.7.
>
>You will recognize that a DR of 2.7 is extremely high. It would
>probably work well with salted paper and VDB, and maybe albumen, but
>not with any of the other processes we normally discuss on list.
>
>
>Sandy
>
>
>
>
>>Also, if I have a neg with an range of 9 stops, using the ratio
>>below, does that mean the DR of the neg is 2.7????
>>
>
>
>thanks again,
>
>n
>
>----- Original Message -----
>
>From: <mailto:jkschreiber@earthlink.net>Keith Schreiber
>
>To:
><mailto:alt-photo-process-l@skyway.usask.ca>alt-photo-process-l@skyway.usask.ca
>
>Sent: Wednesday, September 10, 2003 10:11 AM
>
>Subject: Re: DR vs. f-stops
>
>
>Do you mean something like: 1 stop = 0.3 density units ?
>
>
>
>Keith
>
>----- Original Message -----
>
>From: <mailto:nick@mcn.org>Nick Makris
>
>To:
><mailto:alt-photo-process-l@sask.usask.ca>alt-photo-process-l@sask.usask.ca
>
>Sent: Wednesday, September 10, 2003 8:45 AM
>
>Subject: DR vs. f-stops
>
>
>Dear Sensotomitrists(sic),
>
>
>
>For those of you really into the technical side of all this, you
>probably have the answer(s) to these questions.
>
>
>
>Is there a linear association between f-stops and dynamic range?
>
>
>
>Regardless of whether it's linear or not, what is the association?
>
>
>
>
>
>Many thanks,
>
>
>
>Nick
>
>
>
>
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