Progress on XTOL-concentrate

[Photo Engineer]

AAAAAAAAAAAAAAA! I scream every time someone asks about % which is about once a month.

There is weight / weight, weight / volume, volume / weight, volume / volume and thus you see how solutions are "written up" in the chemical literature when % is to be expressed.

True % is, for a 10% solution of a solid in water, 10 g of solid and water to 100 ml for wt/vol, or 10 g of solid and 90 g of water for wt/wt.

It goes on. All of these different methods exist for handy use of viscous or organic solutions, especially in the dark.

PE

 

[albada]

AAAAAAAAAAAAAAA! I scream every time someone asks about % which is about once a month.

I asked about this last month, so you were due for another.
Anyway, D316 is passing more tests:

• It can be stored in the refrigerator with no precipitation.
• It can be stored in the freezer with no precipitation. When frozen, I believe it will last years.

I'm starting to test various films with D316, and FP4+ did fine. Its density-curve matches XTOL, shown below.



The curves are close enough. I think using a dev-time of 16.25 minutes (instead of 15.7) would be an excellent match. But I ran out of HP4+, so it's time to give Freestyle some business. BTW, you'll notice all my graphs have a small inflection at X=1.5. That's because the illumination of my light-table isn't uniform, and 1.5 is the transition between the two rows on the Stouffer chart. For comparisons with frames shot the same way but developed in XTOL, it makes no difference.

Mark Overton

 

[Photo Engineer]

Mark, can you photograph a resolution chart and compare the two developers?

Thanks.

PE

 

[kb3lms]

Some feedback!

On Wednesday evening I finally threw out the dead XTOL and got around to making some D316 concentrate and have processed one 35mm film. It worked! The film is drying so I have not yet scanned or printed anything. The negatives look normal, but dark, see info below. Some comments:

The quantity concentrate I made was for 5 liters. 5 liters required 0.25 grams phenidone which was the smallest amount I felt I could accurately measure.

1) I started with 17ml PG per liter, so 80ml total. I should have ended up with 110ml of finished concentrate, but instead ended up with 120ml. Now I used 8 mol Sodium Metaborate (3g/L so 15g total). Possibly this made the difference? Would starting with, say, 15ml PG per liter pose a problem?

2) Mix temp was 85C. Absolutely no problem dissolving anything and no signs of crystallization.

2) One liter of working solution was prepared using 22ml of concentrate as directed and 45g sulfite.

3) Resulting pH was 8.3. This was adjusted down to ~8.2 using dilute (5%) acetic acid.

4) The film processed turned out to be ORWO UN-54. I had thought it was Legacy Pro 100 (aka Acros) as that is what was marked on the casette. According to the Massive Dev Chart iPhone app, Acros in stock XTOL is processed for 8:00 min, which has worked well for me in the past. Multiplying by 1.9 (as given about IIRC) gives 15.2 minutes but I rounded and used 15. The processed UN-54 looks 1.5 to 2 stops pushed so it's a bit dark.

5) My time for UN-54 in stock XTOL is 6:30. Multiplied by 1.9 gives about 12:20, which judging from the results I would guess is about right.

So, there is some user feedback for you. I'll post a bit more once I have printed/scanned some.

-- Jason

 

[albada]

Mark, can you photograph a resolution chart and compare the two developers?

Did you know that I have a 4-day weekend and thus have time to run more tests?

I ran XTOL-vs-D316 resolution tests on TMY-2, using a 50mm lens 30 focal-lengths away from the target at f/5.6 for best sharpness. But the negatives resolve a little past my scanner's Nyquist-limit of 57 lp/mm. Scanning won't work for this, so I used my 100X microscope. The numbers:

TMY-2 in XTOL resolves 65 lp/mm.
TMY-2 in D316 struggles to resolve 65 lp/mm, but the prior tile of 59 lp/mm was fine. So let's call it about 62 lp/mm.
​

Comments about these results?

Mark Overton

 

[albada]

On Wednesday evening I finally threw out the dead XTOL and got around to making some D316 concentrate and have processed one 35mm film. It worked!

Jason, congratulations on getting it to work! Let's take a look at the high pH.

1) I started with 17ml PG per liter, so 80ml total. I should have ended up with 110ml of finished concentrate, but instead ended up with 120ml.

Assuming all water was steamed out, the chemicals should increase the volume of solution by about 4 ml/L. So 16 ml of PG yields 20 ml of concentrate. You got 120 ml, and assuming it was hot long enough to steam-out all the water, you must have started with (120/5)-4 = 20 ml of PG. Do you think that's possible?

Regardless of what happened, you got 120 ml, so you should use 120/5 = 24 ml/L of concentrate. You used 22 ml, which is not enough and would cause the pH to rise a little (concentrate pulls down the pH). But I doubt that lack is enough to bring it up to 8.3. Is your pH-meter calibrated? I've found that they soon go way out of cal. Anyway, it sounds like you're close enough. You might try it without adding acetic acid and using 24 ml/L, and then dial-in the correct time.

The 1.9 factor is a reasonable starting-point. Today I'm dialing in the time for Tri-X, and a roll that's now drying should tell me how close I got.

Oh, the 4-mol vs 8-mol should make no difference. You correctly used 3*5 g of 8-mol, which is fine. OTOH, I haven't actually tested 8-mol, so I'm only going on theory here.

Anyway, once you get the time figured out, I'd like to see scans of what you get.

Mark Overton

 

[albada]

Tri-X with D316

Here's the comparison of XTOL and D316 for Tri-X. These are 36-shot rolls, not test-strips:



The density-curves match almost exactly up to X=2.3. But an interesting thing happens after X=2.3: XTOL's slope suddenly drops, but D316's slope stays unchanged, causing the curves to diverge. If you ask me, XTOL's curve will cause worse gradation in highlights than D316, because D316 remains more linear through the highlights. If I were a user of Tri-X/XTOL, I'd be annoyed at the worse gradation in clouds, snow and white clothing. D316's curve is better.

That sudden slope-drop in XTOL is odd. Any idea of the cause of that drop or the lack of drop in D316? Did I overdevelop D316? Or is the better buffering in D316 causing highlights to stay on track better?

Mark Overton

EDIT:

It gets stranger. Here are plots of D316 at 13 and 13.5 minutes:



They look almost the same! But grain is definitely better at 13 minutes, matching XTOL in my loupes. It seems that increasing time boosted grain but not density. Maybe I'll try 12.5 minutes for the fun of it.

 

[Photo Engineer]

Mark;

It looks like you have nailed it pretty much on the nose.

PE

 

[kb3lms]

Mark,

Your results sound very encouraging! I don't have a densitometer so I cannot measure any densities. Something to put on my list!

Assuming all water was steamed out, the chemicals should increase the volume of solution by about 4 ml/L. So 16 ml of PG yields 20 ml of concentrate. You got 120 ml, and assuming it was hot long enough to steam-out all the water, you must have started with (120/5)-4 = 20 ml of PG. Do you think that's possible?

I made a typo in my posting above, 17ml*5 is 85ml. Anyway, 85ml is the amount of PG I started with. Now, wrt steaming out water, I cannot say. The beaker was heated in a water bath but I doubt I have gotten 20ml extra water from that. I calibrated the pH meter right before measuring but I am starting to question it's accuracy as I leaned a few months ago I had been storing it incorrectly. It's stored properly now, though.

-- Jason

 

[albada]

It looks like you have nailed it pretty much on the nose.

@PE: BTW, I posted numbers from a resolution-chart a few postings ago (XTOL=65, D316=62 lp/mm for TMY2). Would you say those are good/bad/indifferent?

@kb3lms: Regardless of what happened, you've got 120 ml now. So using 120/5 = 24 ml/L should work, and I think you'll be fine. The chemistry won't be exactly the same as D316, but close enough. My worry would be if some water got in, longevity will be worse. I suggest storing the D316 in the freezer.

Mark Overton

 

[Rudeofus]

My worry would be if some water got in, longevity will be worse. I suggest storing the D316 in the freezer.

Since the issue with water in your concentrate has been bugging you for many months now, some volunteer should finally set up a quantity of your concentrate, split it in half and mix one half with some amount of deionized water. With repeated activity tests every 1-3 months we could learn whether traces of water are likely going to reduce the shelf life of this concentrate.

Note that quite a few people will be reluctant to heat toxic and caustic chemicals close to 100°C, so it would be quite helpful to learn if a concentrate with reasonable shelf life could be made without steaming out the water.

 

[albada]

Since the issue with water in your concentrate has been bugging you for many months now, some volunteer should finally set up a quantity of your concentrate, split it in half and mix one half with some amount of deionized water. With repeated activity tests every 1-3 months we could learn whether traces of water are likely going to reduce the shelf life of this concentrate.

Yes, that would be a good test.
Gerald Koch (there was a url link here which no longer exists) that such chemicals will eventually dissolve at room-temperature. So the issue is the water that did not get steamed out.

Note that quite a few people will be reluctant to heat toxic and caustic chemicals close to 100°C, so it would be quite helpful to learn if a concentrate with reasonable shelf life could be made without steaming out the water.

The chemicals involved are:
* Propylene glycol, a food-additive (non-toxic).
* Sodium metaborate, slightly toxic, and at pH 10.5, not particularly caustic.
* Ascorbic acid (aka vitamin C), non-toxic, and at pH 3, not particularly acidic.
* Phenidone, almost non-toxic.

So getting the chemicals on you will be harmless. The temperatures involved are 85C at most, which is well below what's used for cooking. So there's a lower danger of scalding with D316 than with cooking. Also, D316 can be mixed at 65C (I've done it), reducing scald-risk even farther below cooking-risk.

Overall, I'd say mixing D316 is safer than cooking.

Mark Overton

 

[albada]

Tri-X results

Tri-X developed in D316 for 12.75 minutes looks good. Here are the density-curves of D316 and XTOL:



Curves: In the graph, you can see that D316 is close to XTOL, but provides a little more linear gradation as you go from midtones into highlights.

Grain: In my loupes, grain of D316 ranges from same as XTOL to slightly better than XTOL, depending on density.

Sharpening: D316 sharpens Tri-X some, but clearly less than XTOL (sharpening of TMY-2 is about the same). If you want high sharpening, D316 with Tri-X is not for you. But lower sharpening is a benefit if the fringes (Mackie lines) from sharpening bother you.

Overall, I prefer D316 over XTOL due to its nicer grain and better linearity.

Mark Overton

 

[albada]

Neopan 400 Results

Neopan 400 works well with D316. Here are curves comparing it with Tri-X. Notice that Neopan 400 compresses highlights less than Tri-X.



Here are the films I've tested with D316 so far, along with their dev-times, which all happen to be a whole number of minutes:

Tmax-400 ........ 12
Tri-X ............... 13
Neopan 400 ...... 14
FP4+ ............... 16

I plan to test Tmax-100, Acros and most Ilford films, including Pan F+. Any other ideas?

Mark Overton

 

[Rudeofus]

I plan to test Tmax-100, Acros and most Ilford films, including Pan F+. Any other ideas?

I've tested Delta 3200 with D316 1+1 and negs look great, prints will follow soon. Dev time was 36 minutes (2 times Xtol times for Xtol 1+1 and Delta 3200). This test did not yield a characteristic curve or anything, but shows that higher dilutions of D316 seem feasible (Delta 3200 is usually quite demanding).

For those mixing fresh: you can use the easier to get Borax instead of Metaborate: replace 2.2 g of Sodium Metaborate Tetrahydrate with 2 g Borax and at the end of mixing adjust pH to 8.0 with Sodium Hydroxide (Sodium Carbonate should also work at this pH). Don't leave out the Propylene Glycol as it is said to influence the behavior of the Borate ion (and as a result buffering and pH).

 

[albada]

I've tested Delta 3200 with D316 1+1 and negs look great, prints will follow soon. Dev time was 36 minutes (2 times Xtol times for Xtol 1+1 and Delta 3200). This test did not yield a characteristic curve or anything, but shows that higher dilutions of D316 seem feasible (Delta 3200 is usually quite demanding).

For those mixing fresh: you can use the easier to get Borax instead of Metaborate: replace 2.2 g of Sodium Metaborate Tetrahydrate with 2 g Borax and at the end of mixing adjust pH to 8.0 with Sodium Hydroxide (Sodium Carbonate should also work at this pH). Don't leave out the Propylene Glycol as it is said to influence the behavior of the Borate ion (and as a result buffering and pH).

Wow! Thanks for doing this. It's good to know that it will perform well diluted 1+1. And I haven't tried Delta 3200 either, so that's another film to add to the known-to-work list.

For folks who wish to mix fresh (directly into water), the dev-times should be boosted by 10-15%. That's because a PG-concentrate develops faster than when mixed directly into water. Any idea why? Perhaps the esters formed in the concentrate don't dissociate when dissolved in water? Anyway, I notice that adding PG directly into water slows development, so you could try omitting the PG, resulting in this simple formula:

Sodium sulfite ........................... 45 g
Sodium metaborate dihydrate ...... 2.2 g (or 3.0 g of s.m. tetrahydrate)
Ascorbic acid ........................... 4.5 g
Phenidone ............................... 0.05 g

I developed a roll of Acros last night, which looks fine. I hope to take measurements this evening.

Mark Overton

 

[kb3lms]

Isn't PG a development accelerator? I know PPG and PEG are. Possibly when mixed in the concentrate it is combing with one of the other components so that it can get into the emulsion and act as an accelerator. But, when mixed directly into water it's ineffective. Just a guess.

-- Jason

 

[Photo Engineer]

Polyols are known, in generaal, as development accelerators and are used in emulsion coating as just that along for their other property of being humectants.

PE

 

[albada]

Polyols are known, in generaal, as development accelerators and are used in emulsion coating as just that along for their other property of being humectants. PE

The effect of PG on development-speed is interesting. Here are the times for D316 with TMY2:

Direct to water with No PG ......... 13 min (i.e., the formula I posted 3 postings ago)
Direct to water with PG ............. 13.75 min
PG-based concentrate ............... 12 min

So adding PG to water slows development, but when the PG is in a concentrate, it accelerates development. Weird, isn't it?

Mark Overton

 

[Photo Engineer]

I certainly cannot explain it.

PE

 

[Rudeofus]

So adding PG to water slows development, but when the PG is in a concentrate, it accelerates development. Weird, isn't it?

This is a wild guess but maybe it inspires more educated guesses: I have read it many times that PG forms an ester with the borate ion, and my little high school chemistry knowledge tells me that esters are more likely to form when water is forcibly removed. If all this is correct, I would assume that PG-Borate ester is formed in the concentrate version, which may have different properties from Borate and PG alone. It would be interesting to know whether different pH adjustments are needed with concentrate or fresh mix.

Since Mark observed that a given amount of PG has much more pronounced effect on small test clips than on whole rolls of film, it looks like PG somehow interacts with the gelatin or some other part of the emulsion.

PS: About the 1+1 dilution: I did an 120 roll in 500ml of developer, which means my results may or may not apply to 35mm rolls souped in 250ml.

 

[albada]

At this point, I think we can conclude that D316 will not fail with low-speed films, as DS-10 did. I've tested the following slow films:

Ilford Pan-F+, Ilford FP4+, Fuji Acros​

All did fine in D316.

Yesterday, I ran some rolls of Delta-400 in both XTOL (7.5m) and D316 (15.75m), and compared them on the light-table. Measurements and loupes show results similar to Tmax-400: Compared with XTOL, D316 gives about the same film-speed, slightly finer grain and a little less sharpening. Here are the graphs of Delta-400 in both soups:



As we've seen before, D316 also creates a higher shoulder, which I suspect is due to D316's stronger buffering. That will give better gradation in things like clouds, snow and white clothing. But this improvement is substantially better than what I've seen in other films. Any idea why? Using Ilford's recommended time of 7.5m, Delta-400 in XTOL gave a Contrast Index (CI) of only 0.50. But 0.58 is needed to print at grade 2, so this is a little low (grade 3?). In the graph, D318's CI is 0.52. I matched XTOL's CI so that I could compare grain, but I suggest using a little longer time to boost contrast.

Here are the times I have so far:

Tmax-400 ......... 12
Tri-X .................. 13
Acros ................ 13
Neopan-400 ..... 13.75
Pan-F+ ............. 12.25
FP4+ ................ 16
Delta-400 ......... 16.25

Today I'll be souping some Tmax-100.

Mark Overton

 

[Bruce Osgood]

Today I'll be souping some Tmax-100.

Mark Overton

I'd like to know your results with Delta 100.

 

[albada]

A surprising result: With Tmax-100 (TMX), D316 acts like a compensating developer. Here's the graph of D316 and XTOL:



Compared with XTOL, D316 has (1) a slightly higher toe (giving a bit higher film-speed), (2) same midtones, and (3) compressed highlights. With most films, D316 gives the same or higher shoulder; with TMX, the shoulder is lower and sooner. While helpful for high contrast scenes, this is supposed to be a general purpose developer. The leader density is also lower (2.11 vs 2.28).

Any idea why this happened? I believe that compensation occurs due to either a drop in pH (poor buffering) or developer starvation. D316's buffer/phenidone ratio is better than XTOL. Its AA/phenidone and sulfite/phenidone ratios are similar, so why would the phenidone be starving?

Is this simply a case of underdevelopment?
Would multiplying the amount of both sulfite and concentrate by 1.5x or 2x help?
Or perhaps boost the sulfite in order to boost pH closer to 8.2?

Mark Overton

@Bruce: When I'm done with Tmax-100, I'll test Delta-100.

 

[Photo Engineer]

Mark;

I would suspect underdevelopment until proven otherwise.

PE