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Rudeofus
02-20-2012, 04:26 PM
Looks like I'll need to do the equivalent: Put more developer into each liter. I'd like the dev to work conveniently with 1-roll tanks.
There could be a substantial difference between a lot of low concentrate and just enough of high concentrate, and the small reported grain may come from that difference. As I have mentioned before, I don't think that we with our limited resources can so easily beat Xtol in all respects, but we are at liberty to relax some of the rules which bound Xtol's designers. One of them would be "don't require more than 250ml for a 36 exp roll of 135 film". Note that if we needed at least 600ml to develop one roll of 120 film (which has same area as a 36 exp 135 film), this wouldn't even require a change of process for me, I never put more than one 120 roll on a spindle.


Then shouldn't XTOL also come out orange? In fact, it comes out almost clear.
Xtol is more concentrated, works at a much higher pH and may have some chems added to kill the sensitizing dyes. You wrote you tried upping Phenidone content, did this make any difference?

BTW: If you don't like wasting whole film rolls on testing dev capacity, how about roller development? This would use a lot less soup hence would allow you to test with less film.

Michael R 1974
02-20-2012, 04:40 PM
Here's an interesting idea: Deliberately let the dev-agents be destroyed during development. This will cause them to be most active during the early part of development, and slow down near the end when grains are getting large. Perhaps this will reduce filament-formation and thus reduce grain. Physical development would presumably be more prominent near the end (i.e., higher physical/direct ratio). Or has this idea already been tried and rejected?

Mark Overton

"Controlled exhaustion" of the developing agent is the principle underlying high acutance developers such as Beutler, FX1/FX2, Pyro formulas etc. It is also why true acutance developers are typically compensating by nature.

Rudeofus
02-20-2012, 05:17 PM
"Controlled exhaustion" of the developing agent is the principle underlying high acutance developers such as Beutler, FX1/FX2, Pyro formulas etc. It is also why true acutance developers are typically compensating by nature.

Michael, the controlled exhaustion in high acutance and/or compensating devs you all are writing about is a local effect. This has nothing to do with using insufficient developer in the whole soup and the results will be different, especially in the shadow region. Note that Beutler uses more Metol than D-76 but no super additive dev, which means it exploits local effects.

Photo Engineer
02-20-2012, 05:50 PM
Maybe I should teach that workshop in the design of developers and fixers!

PE

Alan Johnson
02-20-2012, 07:15 PM
If a low concentration of developing agents is used uniform throughout the solution,as in rotary processing, there is still an adjacency effect resulting from local concentration differences within the emulsion,see "Controls in Black and White Photography" by R.Henry p240,which gives results for the Beutler with Tri-X.
So if very low (but uniform throughout the solution) concentrations of phenidone/ascorbate were used,requiring much agitation to get development in a reasonable time,it seems adjacency effects would still occur within the emulsion.
But films like T-max show very little adjacency effect,I believe it was considered due to their high iodide content.

Michael R 1974
02-20-2012, 07:51 PM
Michael, the controlled exhaustion in high acutance and/or compensating devs you all are writing about is a local effect. This has nothing to do with using insufficient developer in the whole soup and the results will be different, especially in the shadow region. Note that Beutler uses more Metol than D-76 but no super additive dev, which means it exploits local effects.

Yes agreed, when we refer to controlled exhaustion it has to do with local effects. This should not be confused with exhaustion due to there simply being insufficient developing agent to fully develop the negative.

Michael R 1974
02-20-2012, 07:52 PM
Maybe I should teach that workshop in the design of developers and fixers!

PE

That would be really great!

Photo Engineer
02-20-2012, 07:57 PM
Yeah? Where, when and who would be interested?

PE

Mustafa Umut Sarac
02-20-2012, 08:28 PM
at my home in istanbul , anytime , if it would be my home , may be my mother , my cat and of course I will be there and the strangers who would like to see and touch a real american cowboy

Photo Engineer
02-20-2012, 08:50 PM
Cowboy? I can't even ride a horse very well! ;)

PE

Michael R 1974
02-20-2012, 08:54 PM
Not sure where, but I'd be interested, unless it is overseas. In fact the only reason I haven't been to the Emulsion Making/Coating course at GEH is it is always scheduled during quarter end so I can never take those days off from work.

MattKing
02-20-2012, 09:29 PM
Cowboy? I can't even ride a horse very well! ;)

PE

PE:

Maybe Umut means a space cowboy :whistling:

albada
02-20-2012, 09:41 PM
Yeah? Where, when and who would be interested? PE

I'd be very interested. Anywhere in San Diego County (California).

The problem is, we are scattered all over the world. I think a booklet or book would be most valuable, as this information doesn't seem to be documented anywhere. The photo-chemistry books cover various aspects of the chemistry, but little about the trade-offs involved in engineering such formulae.

Another document I want is a list of chemicals describing what they do, what they're used for, and their interactions. The pharmacopea (sp?) chapter in TDC (or FDC?) is a good start and helped me greatly, but I'd like to see much more depth.

Mark Overton

Photo Engineer
02-20-2012, 09:45 PM
Well, Bill Troop and I have been discussing such a book. Since it must draw on Anchell and Troop though, we must rely on Steve to either help with the book or let us use some copyright material or even worse, start from scratch - which is hard to do and time consuming.

PE

Michael R 1974
02-21-2012, 09:36 AM
PE, would the book essentially be based on Anchell/Troop but taken further into detail?

Photo Engineer
02-21-2012, 11:27 AM
Michael, IDK yet. Bill and I have talked about it and exchanged notes but it would be a very much in-depth coverage of the design parameters used in several developers, fixers and there would be a new color section. We want to start where A&T left off and do much more. Steve, at the present, has been uninterested in the project so we are trying to see what we can do. If Bill and I can't come up with something, I may go on to Volume 2 of my emulsion book or I may begin to design some new developers and fixers. However, you must know that the market is shrinking so fast that the emulsion work seems more relevant.

PE

albada
02-21-2012, 12:51 PM
Yeah? Where, when and who would be interested? PE

Here's an idea:
Do the workshop through Skype.

Skype is free within its network, is worldwide, supports audio and video, supports all the platforms (linux/mac/windows/android), and supports conferencing.
My siblings have a cyber family-reunion a couple of times a month via Skype, internationally, for free. So I know it works well.

If a somebody only wants to watch the workshop, he only needs speakers on his computer.
To participate, he also needs a microphone.
For others to see him, he also needs a camera.

Something to consider...

Mark

Alan Johnson
02-21-2012, 01:03 PM
Temporary diversion,for possible use of spoon measures in this project I measured the weight of sodium sulfite anhydrous in one LEVEL teaspoon.Sulfite was scraped level with the top of the spoon with a piece of card.Results are the average of 10 weighings for each of 4 spoons sourced in the UK,marked 1tsp or marked 5ml(pharmacy spoons).
Poundland........................13.7g +/- 0.2g
Asda(Walmart owned).........6.7g +/- 0.1g
Boots pharmacy.................6.3g +/- 0.1g
Independent pharmacy........6.1g +/- 0.1g

Conclusion:cannot rely on marking on the spoon, need to check weight of sulfite in level spoon before using it.
I may use 1 level Asda TABLE spoon which weighed in at 24.0g +/- 0.4g to make up sulfite solution.

albada
02-21-2012, 02:45 PM
Temporary diversion,for possible use of spoon measures in this project I measured the weight of sodium sulfite anhydrous in one LEVEL teaspoon.Sulfite was scraped level with the top of the spoon with a piece of card.Results are the average of 10 weighings for each of 4 spoons sourced in the UK,marked 1tsp or marked 5ml(pharmacy spoons).
Poundland........................13.7g +/- 0.2g
Asda(Walmart owned).........6.7g +/- 0.1g
Boots pharmacy.................6.3g +/- 0.1g
Independent pharmacy........6.1g +/- 0.1g

Conclusion:cannot rely on marking on the spoon, need to check weight of sulfite in level spoon before using it.
I may use 1 level Asda TABLE spoon which weighed in at 24.0g +/- 0.4g to make up sulfite solution.

Alan, thanks for going through this effort. It would have been handy if the world used consistent sizes of teaspoons.
I bought a spoon-set from the local grocery store (Vons). Its measurements:

Vons.............................. 7.3g +/- 0.2g

Here's another idea:

Electronic gram scales with resolution of .1g or .01g are cheap. They only cost US$15-20 or 5-18. Search for "scale .01g" at these sites:



amazon.com
amazon.co.uk


Given that these are so cheap, I think it's reasonable to require that somebody mixing sulfite and concentrate use one.
BTW, I am measuring concentrate by weight instead of volume because it's easier and probably more accurate.

EDIT: You can also search for "taschenwaage .01g" at www.amazon.de. Typical prices are 10-20 Euros.

Mark Overton

Photo Engineer
02-21-2012, 04:50 PM
I have posted a test here of one tablespoon type with NaBr from 3 sources. The error was over 20%. I do NOT recommend use of volumetric measure for solids.

Now, before gun aficionados weigh in saying you use volumetric measure for reloading powder into shells, I remind you of two things.

1. Powder companies make the powder more uniform than most crystalline chemicals for even burning purposes.

2. Powder measure use grain cutting to insure that each load is as close to identical as possible. We don't cut crystals of chemicals that protrude up above the edge of the spoon! :D

PE