Paper Devloping Time

[asaphoto]

Hey everyone,

I would like some clarefacation on how long paper should be devlopated. I have been processing my Forte Polywarmtone in Dektol for about 3 minutes. i think i may be over devloping though. I have heard the you should process 20% more than 5 times as long as it takes for the blacks to apear in the devloper. Waht are everyone elses thopughts on this?

 

[Neal]

Dear asaphoto,

Modern paper should be developed to completion. Your developing time is not unreasonable as you could probably miss by 20 seconds and not be able to tell the difference.

Neal Wydra

 

[Roger Hicks]

The 'Watkins factor' approach (a multiple of the first appearance of the shadows) varies with the emulsion and the developer. As Neal said, you can't overdevelop as the paper is meant to be developed to completion. Three minutes is not too long, but do you see any different quality if you develop for only 2-1/2 or 2 minutes? Or indeed 4?

Cheers,

R.

 

[dancqu]

Modern paper should be developed to completion. Neal Wydra

I've studied an interesting set of curves put together
by Phil Davis. Interestingly there appears to be more to
completion than one might first expect.

The paper tested reached maximum density some time
before reaching maximum contrast; perhaps twice the
time in the developer for maximum contrast and that
as much as plus half a grade.

Likely the paper tested is typical of others although
some variation is to be expected. Dan

 

[BBarlow690]

I tested papers and developers at two development times. Forte/Dektol2 minutes is different from Forte/Dektol/6 minutes. And yes, I compensated as needed for nlarging exposure.

They looked different. Subtly, but one was preferable to the other aesthetically.

You can download the articles I wrote for free from www.circleofthesunproductions.com. The developers article may be the most useful. A little dated, but still interesting, I think.

In the end, it's worth a half hour's experimentation to actually see the differences and decide what YOU like best.

 

[jstraw]

The paper tested reached maximum density some time
before reaching maximum contrast; perhaps twice the
time in the developer for maximum contrast and that
as much as plus half a grade.

This seems counter-intuitive to me. At max density, the blacks will be as black as they can get. Whites start out as white as they can get. It seems possible that you could lose contrast past the time for max density but not to gain contrast.

What am I missing?

 

[Lowell Huff]

Paper development can be graphicly shown by taking the standard negative curve and rotating it 90 degrees to the right. The D min is now in the upper left corner and the D max, lower right corner. This tells you that the "toe" and "mid tones" develop first, then the contrast and lastly D max.

 

[dancqu]

This seems counter-intuitive to me. At max density,
the blacks will be as black as they can get. Whites start
out as white as they can get. It seems possible that
you could lose contrast past the time for max density
but not to gain contrast. What am I missing?

I also missed some thing. Mr. Davis did not tell all. A closer
look at the curves indicates less exposure for maximum black
with extended development. B. Barlow's pdf confirms that but
he does not say any thing about the increase in contrast.
Davis though does mention the change in gradient.

So, to develop to completion, at least to Davis' mind is
to go for maximum contrast; less exposure more time in
the developer. He tested several papers that way.

I wonder where the end points might be. Dan

 

[jstraw]

I also missed some thing. Mr. Davis did not tell all. A closer
look at the curves indicates less exposure for maximum black
with extended development. B. Barlow's pdf confirms that but
he does not say any thing about the increase in contrast.
Davis though does mention the change in gradient.

So, to develop to completion, at least to Davis' mind is
to go for maximum contrast; less exposure more time in
the developer. He tested several papers that way.

I wonder where the end points might be. Dan

Ok, that sheds some light on the subject but if it's true that "to develop to completion, at least to Davis' mind is to go for maximum contrast," then I disagree with Mr. Davis. To me, "completion" means there's no more density to be gained by further development time. I think this can only be judged by the bahavior of the silver in the highlights since one may see maximum density in the shadows before all the apparent tone in the highlights is realized.

From the moment that blacks are black onward, as you are still gaining density in the higher values, you are continually losing contrast. Controlling contrast comes from selection of paper grade or filtration and paper exposure time.

It seems to me that the time to "completion" for any paper/developer combination really doesn't have a thing to do with exposure time. I'd imagine a valid test would be to do something like expose a test sheet by moving a card in increments and develop it for a really long time, like six minutes and Identify the first exposure that's discernable from paper white. Then expose a full sheet for that amount of time, cut it into one inch strips and develop strips for 90, 120, 150, 180, 210, 240, 270, 300, 330 and 360 seconds (mark them on the back before development). Find the one that matches the overlong development time, go one increment further just to be safe and that's development to completion.

If you wanted confidence that you were getting maximum black at that time, you could run a set of strips the same way, exposed for the time that produced the first loss of distinction between one time and the next longer time. I'm sure that not only would the time for completion (as determined by the previous test) but that a number of the black tests strips developed for shorter times would be just as black.

I don't know if I've made sense here.

 

[jstraw]

Ok, if dmax comes up LAST, then just do the second test. Minimum time to achieve maximum black on sheet of paper that's been walloped with light.

 

[dancqu]

[QUOTES=jstraw;458698]
"Ok, that sheds some light on the subject but if it's true
that "to develop to completion, at least to Davis' mind is to
go for maximum contrast," then I disagree with Mr. Davis."

That most contrast was for the purpose of the tests he
made on three Forte papers. Quote: "I was satisfied that
Dmax was reached is less than a minute and that there was
no appreciable change in curve shape or gradient after a
minute and a half ..." 1:30 was used for all tests. ??
His curves show times of 45, 1:30, and 3:00.
Polygrade V was the base paper.

"To me, "completion" means there's no more density to be
gained by further development time. I think this can only be
judged by the behavior of the silver in the highlights since one
may see maximum density in the shadows before all the
apparent tone in the highlights is realized."

Looking at the curves max black for 3:00' was a stop less
exposed than the same black at 45" . The gradient was very
nearly the same as for 1:30". No, there is no more density to
be gained; max black is maximum. If that is achieved by less
exposure and extended development then maximum contrast
and density coincide. The curves do not lie. Makes me wish
I had a reflection densitometer.

"From the moment that blacks are black onward, as you are
still gaining density in the higher values, you are continually
losing contrast. Controlling contrast comes from selection
of paper grade or filtration and paper exposure time."

This "Controlling contrast ... and paper exposure time". then
This "... time to completion ... doesn't have a thing to do with
exposure time."

If time to completion is achievement of Max black then
beyond some minimum exposure it's duration Does affect
time to completion.

The Davis' and Barlow's findings demonstrate that Max
black achieved with less exposure and extended development
does result in an increase in contrast. Going on a full grade
looking at the Davis curves.

I think the explanation lies at the toe of the curve. A half
to full stop less exposure will make for a noticeable drop out
of highlight detail that might other wise show. Dan

 

[jstraw]

I'm gonna read that a few times and try and get my head around it. Thanks.

 

[radiantdarkroom]

3 min dev for FB paper in dektol is the normal development time, RC is 1 min.

 

[nworth]

Development time varies with the developer and to some extent with the paper. The exposure affects your judgement of the development. In a long obsolete edition of "The Print," Ansel Adams recommended determining the exposure needed to get decent (not necessarily perfect) highlights and then determining the development time by seeing how long you could develop the paper without getting development fog. The point just before you see fog is the correct time. Most of today's papers are pretty fog resistant, and developing agents in the paper promote a fast and consistent time to full development. The Adams method may not be fully practical now, but some variation on it can probably be worked out. As a practical matter, you can make a series of prints, starting with the minimum recommended development time and increasing the development time in 30 second steps to twice the maximum recommended time. You select the time for the print before any fog appears but where the highlights no longer gain density. (Use the edges of the first print to judge whether there is fog in subsequent prints. It can be a subtle thing.)

 

[Ryuji]

The paper tested reached maximum density some time
before reaching maximum contrast; perhaps twice the
time in the developer for maximum contrast and that
as much as plus half a grade.

That's more common time course of selenium toning in KRST than developing images...

 

[Ryuji]

The conclusion is already there; 3 min in Dektol is not unreasonably long.

The development time varies depending on several factors. Unless you want warmer image tone, you should develop the paper to completion. I generally give 30 seconds extra development (with continuous agitation) from the moment I can't notice any density building in the developer.

One factor people usually don't talk about is the multigrade papers. Many multigrade papers require longer times to develop images when exposed with soft contrast filter. The time it takes to completion is not much longer but while watching the print with developing image, you'll notice that the image comes out much more gradually. I usually test development time with samples exposed with grade 0.5 filter.

Shortening of development can make the image tone warmer, at least with paper emulsions that are capable of warmtone image. Many people have experience of cutting development time with some test strips and realizing that the image hue is more brown with those. But in order to make the image tone match with what you could get with full development, you'd have to give extra exposure and use half grade harder paper. This is the principle of true warmtone print developers.

 

[jeroldharter]

My practice is to develop in Zone VI developer for at least 3 minutes so that it is more or less "to completion." Also, I find that is long enough so that Even if I develop a stack of 7-8 11x14 inch prints at one time by interleaving them that the development is even.

If I want a warmer tone, different contrast, etc. I use a different paper/developer. I want a system such that if I get the print right with my standard time of 3 minutes, then I can expose 6-8 sheets and develop them all at once. I have read that some use a more dilute developer to achieve a development time of 5-6 minutes for uniformity but that is too much for me.

 

[jstraw]

I suspect that my 2 minutes in Zone VI is probably complete but only marginally so and I might be better off with three minutes.

The longer I participate on APUG, the longer my workflow seems to take...50 minute semi-stand film development...two print bath fixing...now this.