DEVELOPMENT: How Much is 1 Stop

Bruce Osgood

Membership Council
Member
Joined
Sep 9, 2002
Messages
2,642
Location
Brooklyn, N.Y.
Format
Multi Format
I am paying more attention to development compensation for scenes greater and lesser than 6 stops.

Do you use a per-cent value of development time for each stop to be compensated for; if so, what do you consider an accurate per-cent for one and two stops?

I realize there is probably not a fixed value across the board for "all films in all developers all the time", but perhaps there is a generalization that can be applied.

Thank you,
 

mjs

Member
Joined
Mar 15, 2005
Messages
1,123
Location
Elkhart, Ind
Format
Multi Format
Using 100TMX developed in stock D76 in trays, my "Normal" time is 6 minutes. Since I don't have a densitometer I have to judge departures from normal visually, both from the negative and from prints. For me, -1 development is 5 mins. 20 secs. and +1 development is 6 mins. 30 secs. -2 and +2 are similarly non-linear but surprisingly repeatable.

mjs
 

jmal

Member
Joined
Oct 13, 2006
Messages
529
Location
Kansas
Format
35mm
If I remember correctly, Les McLean uses 20% of the normal time to determine one stop difference in development of the negative. Anyhow, I almost always see a fgure of between 15-20%. I use 20% and it works well.

Jmal
 

Donald Miller

Member
Joined
Dec 21, 2002
Messages
6,230
Format
Large Format
There is a difference on expansion compensation as opposed to contraction compensation. They are not linear in the way that one would think...

For instance Tri X in HC 110 dil B is 6 min 15 seconds for a normal scene. It is 10 minutes thirty seconds for N+1 and it is 4 minutes and 30 seconds for N-1.

Thus most films are more reactive to reductions in development than they are to expansions of development.

Most films have a heck of a time to go to N+2 expansion. This is especially true when one gets into the density ranges that alt process requires.
 

Roger Hicks

Member
Joined
May 17, 2006
Messages
4,895
Location
Northern Aqu
Format
35mm RF

For years I've used '15/50' -- 15% less for long brightness ranges, 50% more for short ones.

These figures are not set in stone. You might be happier with 20/60 or 20/40 or indeed 20/50 or 15/60. If you're using rules of thumb like this you can forget exact one-stop +/- compensation but the good news is that you don't NEED to be all that exact.

Cheers,

R.
 

Lee L

Member
Joined
Nov 17, 2004
Messages
3,281
Format
Multi Format
Here are a couple of development time vs. gamma/CI charts. One for Acros and one for Tri-X, taken from manufacturers' data sheets. You can see that rate of change with time varies by developer and isn't necessarily linear. Films obviously vary as well. You might use this kind of data as a starting point, looking for similarities between the developer you choose and those with published data if you don't use a listed developer, but each combination is unique, as is your agitation, use of a pre-soak or not, etc.

Any general guidelines you get are just that, useful as starting points, but unlikely to be a perfect comprehensive answer unless specific to a particular combination of film and developer. In any case there's enough leeway in the whole process that a generic adjusment will probably get you close enough to cover any missed attempts with choice of paper grade, developer, etc.

I've recently used g3data (Dead Link Removed) to extract a series of X,Y data points from curves like these and run regressions on them in a spreadsheet to get a second or third order polynomial expression for the curves. The point of this was to find how well a regression on a set of 3 or 4 observations of gamma for my own tests might predict good times for a specific gamma within the normal range. The answer is "probably much more accurately than necessary".

Lee
 

Attachments

  • Acrosgammas.jpg
    38.1 KB · Views: 67
  • TriXgammas.gif
    21.7 KB · Views: 75
Last edited by a moderator:

jmal

Member
Joined
Oct 13, 2006
Messages
529
Location
Kansas
Format
35mm
I forgot to mention that I was referring to 20% for contraction development. I'm with Roger at around 50% for expansion. By the way, thanks Roger for bringing TX in DDX to my attention. I finally bought some and have put about 8 rolls through it. I feel like I'm getting the best negatives yet. Shooting at box speed. I'm not one to place too much emphasis on materials, but there is a significant difference in the DDX negs. I had good results before, but I really like the look of the prints now. They have grain much like all the classic Robert Frank shots, which is great for me. This is my standard (and only?) developer from this point forward.

Jmal
 

Les McLean

Subscriber
Joined
Oct 18, 2002
Messages
1,606
Location
Northern Eng
Format
Multi Format


Hi Bruce. If you have a copy of my book you will see on page 17 that I suggest 20% increase or decrease per 1 stop and how to calclate 2 stops or more. As has already been said these figures are not set in stone and as you apply the changes in development to suit the lighting condidtions and subject contrast you will learn to make a good educated adjustment (guess). I have used as little as 15% and as much as 50%.
 

Bob Carnie

Subscriber
Joined
Apr 18, 2004
Messages
7,735
Location
toronto
Format
Med. Format RF
Hi Bruce

As a standard reference we always use 30% for one stop.
Lots of good advice on the above posts, the original scene as others have pointed out will be a determining factor. Ball park for us is 30%
 

aldevo

Member
Joined
Oct 4, 2004
Messages
949
Location
Cambridge, M
Format
Multi Format
I'd echo pretty much what others have already recommended.

In flat light I'd rate 400TX at EI 400-500. In really contrasty light I'd rate it around EI 200 with a reduction in development time of around 30%.
 

Michael W

Member
Joined
Feb 11, 2005
Messages
1,594
Location
Sydney
Format
Multi Format
What do people think about this alternative method of contraction?
My normal dev for Tri-X is 10.5 mins in Xtol at 1:2

In contrasty light I make sure that I am exposing for whatever the important shadow details are, probably works out the same as rating the film at 200, more or less. To control the highlights I dilute the dev a bit more.
For a 1 stop contraction I use Xtol at 1:2.5 for 10.5 mins
i.e. usual time but more dilution.

Looks OK, measures OK on a densitometer & I find it easier than changing the time.
 

noseoil

Member
Joined
Oct 6, 2003
Messages
2,887
Location
Tucson
Format
Multi Format
The short answer is a bit complex. Each film, developer and paper combination is unique. To understand a given combination, do some testing and plot the curve of development contrast as a function of development time. On the left axis ("Y") plot contrast in zones, sbr or whatever your method is, for the paper's zone scale on graph paper. On the bottom axis ("X"), use time increments to see the rate of change in contrast. To pick a number which is "right" is a bit of a risk because there are too many variables in the simple question. tim
 

Bob Carnie

Subscriber
Joined
Apr 18, 2004
Messages
7,735
Location
toronto
Format
Med. Format RF
I think what you describe is very understandable and an alternative to changing the time.
 

Lee L

Member
Joined
Nov 17, 2004
Messages
3,281
Format
Multi Format
Goldie,

Contrast control through dilution for HC-110 is addressed in this very short, but interesting thread: (there was a url link here which no longer exists)

Supporting the shadows through a bit more exposure as you do works well. Another method used with greater developer dilution is reduced agitation and lenghtened times, which exhausts developer in the highlights while the shadows build density and contrast. You'll find a lot of discussion of that here on APUG as stand development, semi-stand, extreme minimal agitation (EMA), etc.

Lee
 
You must log in or register to reply here.
Menu
Log in
Register
Cookies are required to use this site. You must accept them to continue using the site. Learn more…