From: Nick Makris (nick@mcn.org)
Date: 09/10/03-12:31:06 PM Z
Re: DR vs. f-stopsKeith, 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: Sandy King
To: 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: Keith Schreiber
To: 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: Nick Makris
To: 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
This archive was generated by hypermail 2.1.5 : 10/01/03-03:09:00 PM Z CST