RE: DR vs. f-stops

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From: Eric Neilsen (e.neilsen@worldnet.att.net)
Date: 09/10/03-09:47:59 PM Z


Nick, This of course depends on "what can be recorded or seen by the
sensitized solution" and what makes the print look right. You can capture a
DR of 2.1 with PD but it is only a loose target for maximizing the scale of
the image from light to dark and should not be used to hang your hat on so
to speak. Different papers and developers will alter that range.

 

Eric Neilsen Photography

4101 Commerce Street

Suite 9

Dallas, TX 75226

http://e.neilsen.home.att.net

http://ericneilsenphotography.com

 

-----Original Message-----
From: Nick Makris [mailto:nick@mcn.org]
Sent: Wednesday, September 10, 2003 1:31 PM
To: alt-photo-process-l@sask.usask.ca
Subject: Re: DR vs. f-stops

 

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: Sandy King <mailto:sanking@clemson.edu>

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 <mailto:jkschreiber@earthlink.net>

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 <mailto:nick@mcn.org>

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

 

 

 


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