Progress on XTOL-concentrate

[albada]

PE will be interested in this.

With 400-speed films, developer 214D produces a curve whose shape matches that of XTOL (example below), but is shifted down slightly. This shift doesn't matter when printing or scanning, but it makes the ISO-defined film-speed drop. Here are the curves for Delta 400. The left graph is the original curves; the right graph shows the 214D-curve shifted up by .02:

-

In the left graph, the 214D-curve crosses the Y=.1 line (.1 above B+F) about 1/2 stop to the right of the XTOL-curve, causing an apparent speed-loss of 1/2 stop. But the shifted curve in the right graph shows their shapes differ insignificantly. So how do I determine film-speed if a vertical curve-shift skews the ISO-number?

Long ago, the ISO standard used a superior method of determining film-speed called "Fractional Gradient" (FG). Stephen Benskin knows all about this. People complained that it was hard to calculate because you had to plot the curve, so ISO changed the standard to an approximation used to this day. I estimated the FG speeds for 214D, and always got at least 400 speed for 400-speed films. It's too bad that today's ISO method punishes a developer for shifting a curve down a little.

If you look at the right graph closely, you'll notice that 214D has a slight speed-loss wrt XTOL, but it's so small that I'll trade it for the finer grain I get. And the FG method says I'm still getting at least 400 speed, so I don't care. Or should I care? Any idea why this brew shifts the curve down a bit?

Some Test Results

Here are results of my testing so far. At a prior poster's request, I'm emphasizing low speed films because they gave Ryuji's DS-10 trouble. Pan-F+ failed with DS-10, but does fine with 214D (and D316).

[TABLE="width: 500"]

Film
Time


Tri-X
13.5


Tmax-100
13


Delta-100
12.25


Delta-400
18


Pan-F+
12.25


FP 4+
16


HP 5+
15

[/TABLE]

In my testing, I've seen two things worth noting:
1. The small downward curve-shift described above with 400-speed films.
2. An early shoulder (compensation) with Tmax-100. D316 did this too. Don't overexpose it. This compensation would be useful for compressing wide-scale scenes, but the cost you pay for this feature is lack of overexposure-latitude. This only applies to Tmax-100. All other films behave normally.

As always, comments are encouraged.

Mark Overton

 

[Photo Engineer]

Mark;

There is a slight error in the shifting of the curves, but no matter. The point is that if the curves are identical in terms of speed as viewed on these curves, then if they print identically, then the speeds are the same. This is one of the faults in measurements of ISO like this.

PE

 

[albada]

I'm almost done testing 214D, and I plan to post a report about it in the articles section when done. Just need to develop a roll of Delta 3200 that I shot this evening.

But T-Max 100 (TMX) gave interesting results: It shouldered off early. In another thread, Drew Wiley said this happens to TMX with several popular developers. So I mixed 214P, which is the same formula, but using .05 g of Phenidone instead of .08 g of Dimezone S. Here are the curves of both with TMX:



Phenidone (green curve) pushed the shoulder out a little, maybe 1/2 stop, and the shouldering isn't as severe. But what's odd is that Phenidone's shoulder is a sudden change of slope. In fact, the green curve is two straight lines. That makes me wonder if the shoulder is actually due to the low-speed emulsion taking longer to develop and thus giving a lower slope in the highlights. But only with some developers.

Also note that Phenidone gives a small apparent speed-increase (per ISO-definition), but at the cost of a softer toe.

Anyway, my advice is: If you shoot much TMX, use Phenidone and accurately shoot at box-speed. Else use Dimezone S.

Mark Overton

 

[Relayer]

Wow; it's been awhile since I posted the formula. Here it is:
Propylene glycol ................. 16 ml
Sodium metaborate 4 mol ..... 2.2 g
Ascorbic acid ..................... 4.5 g
Phenidone ......................... 0.05 g
.....
Here are times in minutes at 20C:
.....

Mark, what about dev.time for this formula? same as XTOL stock/diluted or other?

 

[albada]

Mark, what about dev.time for this formula? same as XTOL stock/diluted or other?

The formula you quoted is for an earlier developer called D316. I changed it a little and am temporarily calling it 214D. Its formula is:

Propylene glycol ................. 12.2 g (same as 11.8 ml)
Sodium metaborate 4 mol ..... 1.8 g
Ascorbic acid ..................... 4.2 g
Dimezone S ....................... 0.08 g (or use 0.05 g of Phenidone)
A litre of developer contains 18 g (same as 15.4 ml) of concentrate and 45 g of sodium sulfite. pH is 8.08.​

The times for this are posted four postings ago on this page (scroll up). If you decide to try it, please post your results. As I mentioned earlier, I plan to post an article about this concentrate after finishing testing.

Mark Overton

 

[Relayer]

The times for this are posted four postings ago on this page (scroll up).

as I found last formula with same time as XTOL is (there was a url link here which no longer exists) ? why you change to twice diluted version?

 

[craigclu]

When I was dealing with Dimezone S a few years back, I had batches lose activity. Fresh Dimezone S would return prior performance, then seemingly lose activity again. 3 sequences had me feeling pretty confident about the Dimezone link to the behavior. Have others had this happen or was I somehow getting batches at the end of their useful life? I became disenchanted at the time and hadn't returned to it (partly from having some success with concentrates in PG right about then and being told that Dimezone S had its main advantages in water-based mixtures). I recall searching out ways to extend its life but didn't discover anything at the time that seemed to show promise.

I'm open-minded about it but mainly curious about others' experiences that might mirror Mark's recent episode and what I had seen?

 

[albada]

as I found last formula with same time as XTOL is (there was a url link here which no longer exists) ? why you change to twice diluted version?

I used the diluted version to save chemicals. When mixing typical developers, I was surprised and disappointed at how much sodium sulfite needed to be poured in. So I decided to use half as much sulfite and double the dev-time to get the same solvent-effect.

When I was dealing with Dimezone S a few years back, I had batches lose activity.

Can you give more details about these failures? Did the Dimezone S fail after mixing it water? Or was it while it was still a powder?

Mark Overton

 

[craigclu]

Can you give more details about these failures? Did the Dimezone S fail after mixing it water? Or was it while it was still a powder?

Mark Overton

In the powder form. I thought it was perhaps the large container that my first batch arrived in with too much air space (100g jars) and when it became suspect, I ordered fresh again and this batch was a darker color and very shortly showed the same behavior. When I ordered again, I had started playing with PG concoctions and was being told that a primary Dimezone S advantage was its stability once in solution and I drifted away, not needing another "variable" on the other things I was involved in then and PG concentrate based. I had been intrigued with Ryuji Suzuki's work which was what had me dealing with the Dimezone S in the first place. There was a bit of discussion among people testing his things back then about the color of their new supply, etc and concern over its storage behaviors. I just haven't gotten back to thinking about it until following your thread and progress here.

I found some go-to combos from that time that I've settled into but get the itch to try some things recently and thought your Xtol alternatives would be interesting, especially with you doing all of the work!

 

[albada]

In the powder form.

Hmmm. Out of caution, I've been storing my Phenidone and Dimezone S in amber glass jars in the refrigerator. After a year, they're still doing fine. But after your experience, I wonder. Where did you buy yours from?

Mark

 

[craigclu]

I got my Dimezone S from:

Dead Link Removed

They were the only easy source for me back then and I could buy 100g quantities. I see they still supply it. They're nice people to deal with and have been a reliable source for things over the years.

 

[albada]

As easy as Rodinal

Alan Johnson had the idea of dissolving sodium sulfite into water ahead of time, creating a sulfite solution that you use over a period of one or more months. Using a concentrate such as 214D is then as easy as Rodinal:

1. Measure 18 g/L (= 15.4 ml) concentrate into a beaker using syringe or scale.
2. Pour sulfite solution up to fill-line. This works out to 1+64 dilution.​

For 214D, you would mix 46 g of sulfite into each litre of sulfite solution. If you wish, this can be stored refrigerated to ensure longevity. Quiz: Why 46 g/L instead of 45? Any idea how long sulfite solution will last?

Then I had the idea of doubling the sulfite (to 92 g/L) and adding some sodium metaborate to the sulfite solution, creating an alkali solution. If you then use 2.5 times as much concentrate, you should be able to make a close clone of XTOL similar to the formula I tested back in July here:
(there was a url link here which no longer exists)

My latest alkali solution consists of:

Sodium sulfite ..................... 92 g
Sodium metaborate 4 mol .... 4.1 g
Water to ............................. 1 L
1L of developer contains 45 g of 214D (=38.6 ml) and the remainder is alkali solution (1+25 ratio of concentrate+alkali solution).​

The pH matches XTOL perfectly, but the developer is too hot (overdevelops), so I need to reduce the metaborate in the solution some to get matching curves when using XTOL's times. Or maybe reduce the amount of concentrate. So I'll do more experiments. Anyway, if this works out, then 214D can be used either in its usual way or as an XTOL-clone.

Mark Overton

 

[Bruce Osgood]

Xtol Concentrate:

Back to the mundane,

In order to avoid messing around with .05 g Phenidone I thought I would double the recipe to use .1 g. I have a triple beam balance that will measure 1/10th g. So my question now is does the 2000 mL concentrate get diluted to a working strength at time of use, and if so, what do you feel is a proper mixture/ratio might be? My process for developing 4x5 inch Delta 100 in Kodaks' Xtol is using a Jobo with constant & continuous reversing rotation and 4 Oz stock solution plus 4 Oz water (8 Oz total solution) for 1 to 4 negatives is all that is required and recommended.

 

[albada]

So my question now is does the 2000 mL concentrate get diluted to a working strength at time of use, and if so, what do you feel is a proper mixture/ratio might be?

I'm confused. Doubling the concentrate's formula will give you 30-40 ml of concentrate. That would be mixed into enough water to produce 2 litres of working developer (and don't forget to add the sodium sulfite). So the dilution is around 1+63 to 1+49, depending on the concentrate.

Regarding weighing: The Phenidone (or Dimezone S) is the tough part, as you pointed out. For doubling, you need .1 g of Phenidone, and if your balance has a resolution of .1 g, then you might be off by half of that .1 g resolution, which is .05g. So a measurement of .1 g might actually give you .05 to .15 g of Phenidone, which is too inaccurate. That's why I recommend using an electronic scale with .01 g resolution. These cost only $12-15; search for "scale .01g" on amazon. Even then, I suggest measuring .1 g very carefully. Quadrupling the formula (60-80 ml of concentrate) means measuring .2 g of Phenidone, which is easy with a .01 electronic scale.

Good luck,

Mark Overton

 

[Alan Johnson]

Sodium sulfite solution available industrially is stable under normal conditions of use and storage but may be oxidized by air (section 10):

https://docs.google.com/viewer?a=v&...P6hPWi&sig=AHIEtbQanAhho7SyYRnxiVguir8UEyHW2w

 

[sun of sand]

I'd say Xtol beats the concentrate in those first two comparison scans both in grain and sharpness. The concentrate seems to have higher contrast or lower shadows eventhough the curves are similar and that makes it seem sharper, to me. I don't think it is anywhere.

Now i see there is a second set of commparison scans so

frame 15 xtol still beats concentrate in sharpness but one of the two has or seems to have better grain ..or different grain. Can't tell which. Obviously better in one area and reverses in another



I have xtol I mixed in early 09 and it still works. Whether it develops the same as when new, who knows. It's been reused after pouring back into glass bottle kept chilled
I still dont understand the need for a concentrate of xtol or amidol

 

[sun of sand]

frame 24 appears that concentrate has slightly finer grain but xtol is still sharper. everything seems equal otherwise

 

[albada]

frame 24 appears that concentrate has slightly finer grain but xtol is still sharper. everything seems equal otherwise

I'm not sure where frame 24 is. Could you give the posting number? It's in the upper-right corner of the posting. For example, this is posting #521.

BTW, having XTOL last 4 years is amazing. You mention keeping it chilled: Do you have issues with precipitate collecting at the bottom of the bottle? When I tried refrigerating my XTOL, I quickly got some precipitation.

Mark Overton

 

[albada]

T-Max 100 -- A nice surprise

I mentioned earlier that with 214D, T-Max 100 (TMX) has an early shoulder, so you must meter accurately at box speed. I considered that a borderline failure until I looked in the loupes. Wow! Fine grain! The grain from 214D is significantly finer than XTOL. Here are scans:

XTOL: 214D:

Grain looks equally better in loupes too. The camera was misfocussed a bit in the second image, so you can't gauge sharpness from these scans. But I examined the Mackie lines outlining the edge-markings in loupes, and sharpening looks the same with both developers.

Films normally give you a grain-speed trade-off. But TMX gives you a grain-shoulder trade-off. With 214D, you get an early shoulder but very fine grain.

-----

I've decided to call this developer "Mocon". Can you guess why? Testing is done, and these are the final times (agitate once/minute for 5 seconds):

Tri-X ................. 13.5
T-Max 100 ........ 14 (meter accurately due to early shoulder)
T-Max 400 ........ 13.5
Delta 100 ......... 12.25
Delta 400 ......... 18
Delta 3200 ....... 25 or longer
Pan-F+ ............. 12.25
FP4+ ................ 16
HP5+ ................ 15
Acros ............... 15
Neopan 400 ..... 14.25​

I'm writing a report which I'll post to the Articles section in apug. Any comments or requests before I call this project finished?

Mark Overton

 

[Bruce Osgood]

Mark Overton Concentrate ?

Make since to me.

 

[Alan Johnson]

Previously it was found that the similar D-316 concentrate went orange after 1 year exposure to air and Mark suggested the color could be used to estimate any needed increase in developing time.
I made the following 3 separate solutions in deionized water and exposed each to air oxidation for 37 days:

Sodium ascorbate 12g/L
Phenidone 0.15g/L
Sodium ascorbate 12g/L + Sodium sulfite 20g/L

Attachments show that the solution containing sodium ascorbate alone went orange, strongly suggesting the orange color is due to the formation of an ascorbate oxidation product, it does not come from phenidone.
Addition of sodium sulfite to sodium ascorbate apparently prevented the formation of the orange compound, perhaps that is why it does not show up in oxidized Xtol.

There is some recent research on ascorbate oxidation in the human retina and also in non-enzymatic browning in foods but I did not find any mention of an orange compound so cannot say what it's name may be.

 

[albada]

@Michael - You got it right!

@Alan - Interesting experiment. Where did you find sodium ascorbate? I couldn't find a source for it here in the states. Anyway, if you still have those fluids, it would be interesting to add some sodium sulfite to the ascorbate and phenidone solutions to see if the colour clears. I'll predict that (1) phenidone's colour will clear because the sulfite should restore the phenidone, and that (2) the orange ascorbate will not clear. The conclusion would be the same as your conclusion: The orange is due to oxidized ascorbate.

Mark Overton

 

[Alan Johnson]

Sodium ascorbate was from ebay, it is a food supplement.
I want to run on the experiment I described to see if the orange compound is furthur oxidized so won't add anything at the moment.

Another experiment I ran was to dilute D-316 concentrate (no sulfite) 1+49 in deionized water and expose to air.For the first 20 days it turned slowly yellow, then during days 21-25 went orange. After 34days I added sodium sulfite 45g/L , a film leader developed in this showed very little blackening, the D-316 was pretty much all oxidized.I divided this solution into two parts and tested each with addition:

(1)Add phenidone-produced a slightly grey film leader.I ran a blank test with phenidone/sulfite only and some boric acid to get the same pH ,this also produced a slightly grey film leader.Conclusion-the ascorbate was completely oxidized and added phenidone was not regenerated.
(2)Add sodium ascorbate-produced a black film leader.Conclusion- some of the phenidone survived 34 days oxidation and was regenerated.

It seems likely all the ascorbate is oxidized first , before the phenidone.

 

[Rafal Lukawiecki]

Testing is done, and these are the final times[...]

Congratulations, Mark! Next time you visit Ireland, let me know and I'd love to buy you a drink—thank you for your impressive work.

 

[PhotoJim]

Where did you find sodium ascorbate? I couldn't find a source for it here in the states.

Photographer's Formulary doesn't have it?