Magic Lith Prototype Update #9 -- EXH Failure

In testing an idea with EXF where I combined ferrous sulfate, hydroquinone, triethanolamine, and carbonate I observed that the developer continued to work for a good amount of time in a beaker, several hours. I wanted to do a control test to see what ferrous sulfate was contributing to the process though. I made the same solution, but with no ferrous sulfate, and ensured that the pH of both solutions was the same. The results were incredibly surprising. The “control” without ferrous sulfate stayed alive for a very long time. Still producing images after 8 hours, though at around 300% slower speed. This seemed promising though, since there in theory was only hydroquinone acting as a developing agent and even if a lot of the hydroquinone oxidized, as long as some was alive infectious development should be possible…

But once again I’m smacked with abrupt failure when trying a similar concoction, EXH1, in a tray with actual paper tests. The developer works for a long time, can develop good blacks, and develops fairly quick at room temperature, but does not exhibit any infectious development. It also requires a lot of bromide to reduce fogging levels. The exact formula is as so:

  • 2L water

  • Triethanolamine (TEA) 100ml

  • Potassium carbonate 12g (6g of 20%)

  • Hydroquinone 1g (in propelyne glycol 10%, 10ml)

  • 2g of bromide (20ml of 10%)

The very high amount of TEA seems to preserve the hydroquinone quite well though the solution does quickly discolor.. However, a big give away is that there is very little red film present on the developer after a few minutes. It also does not give any infectious development, nor other hallmarks of lith printing like colorful highlights. In this the induction period seems to blur into shadow and black development, meaning that with more development the entire image gets darker and more highlights become present. I tested this on many papers, including Kodabrome which is a very good lith paper in traditional formulas. My hypothesis for the reason behind this failure is that TEA reacts, not with hydroquinone nor benzoquinone, but rather reacts with the radical semiquinone to produce some kind of complex which either is a weak developing agent or is not active. In this respect, a large surplus of TEA reacts in the same way as a surplus of sulfite would, it scavenges oxygen and preserves the hydroquinone, but also scavenges the semiquinone and prevents infectious development. With this in mind, HQ mixed into propelyne glycol would be a better “part A” than HQ mixed into TEA. With a lot of research, I’ve found this is a big subject area with very little or no previous research written about it.. However, TEA with other quinone compounds is known to form complexes with semiquinones and is also an electron donor, meaning it can potentially convert semiquinone back to hydroquinone. It appears to be an imperfect preservative compared to sulfite, since the solution will quickly discolor to brown, but either way the end result is that this is a major dead end into a fair number of ideas I had about this. I’m not really sure what else can be done at this point.

Magic Lith Prototype Update #6 - EXB frustrations

In trying to “perfect” EXB, I finally started doing proper note taking and making a progression of prints and seeing exactly what ingredient additions on the print has, as well as trying a few different papers. Previously I was taking rough notes and kinda just faffing about to see what my subjective opinion was on each new print. So, I’m going to try doing this post a bit different, with a literal progression of my prints and the modifications made with each one. Each print (excluding cooltone/133) had a print time of 8s, f/8, and target snatch point was when the tower in the background was a bit beyond grey and getting into infectious black. Each scan was adjusted carefully for color accuracy and black depth

The base formula here is EXB7:

  • 2L water

  • 15ml HQ-TEA 20%

  • 2ml Phenidone/Propelyne glycol 0.1%

  • 10ml potassium iodide 10%

  • 50ml sodium sulfite 10%

  • 1ml potassium bromide 10%

  • 20ml benzotriazole 2%

  • 80ml sodium hydroxide 3%

  • Final pH ~12.5

The first print had significantly too much highlight development and I didn’t keep nor scan it. I added 20ml of benzotriazole and then made this print:

Ilford Warmtone RC, “exb7b”

With this it looked decent, but I wanted deeper blacks and more shadow separation. I added 5ml of potassium bromide.

Ilford Warmtone RC, “exb7c”

This did seem to help tonal separation some as well as increase black levels (probably due to being capable of keeping the print developing longer), but the changes weren’t too significant, and still wasn’t resembling the poorly documented success I had with EXB4. I decided to add 1ml more phenidone mostly just to see what would happen and if previous experiments were correct.

Ilford Warmtone RC, “exb7d”

The results were measurably worse for tonal separation as well as for black depth, probably because it then couldn’t be left in developer as long as previously. Next time I’ll probably opt to start with an even smaller amount of phenidone, like 0.5ml of 0.1% solution. However, since this developer still had plenty of life, I decided to see how it’d treat other papers. I then did Fomatone 133 FB paper (a known “mostly lithable” modern paper) and it produced really nice results. (note exposure and snatch point are different here)

Fomatone 133 FB, “exb7e”

I then tried Adox MC112 FB paper. The results were so bad I didn’t even bother rinsing after fixing. The emulsion had pinholes in it and infectious blacks never came through. Then I decided to try Ilford Cooltone RC. It never went into infectious development so it’s extremely low contrast

Although less complete and granular of a series, I’ll also share a few prints from EXB6 testing

EXB6:

  • 2L water

  • 15ml HQ-TEA 20%

  • 2ml Phenidone 0.1%

  • 20ml potassium iodide 10%

  • 50ml sodium sulfite 10%

  • 1ml potassium bromide 10%

  • 10ml benzotriazole 2%

  • 65ml sodium hydroxide 3%

  • final pH ~12

Warmtone RC, exb6a

With this, things were too eager to go infectious, so I added 10ml of benzotriazole and also 10ml of hydroxide

Warmtone RC, exb6b

And then finally for some reason decided to add 0.5ml of phenidone

Warmtone RC, exb6c

Then I tried slowing down highlights etc more and get deeper blacks and added 10ml of benzotriazole and added 20ml of hydroxide

Warmtone RC, “exb6d”

Afterwards I tried a number of other modifications, especially with additional iodide and hydroxide and all were failures at getting deeper blacks while slowing down highlights.

Overall, these are the things I think I’ve learned:

  • Too much iodide eventually will lighten blacks

  • Magic lith developer formulation seems quite easy if sticking to only a single type of paper.. But the failure here with cooltone RC was especially surprising. Maybe it’s not possible to make an ideal lith developer that works on every paper. You can only make either a mediocre universal developer, or a great specialized developer.

  • Adox MC112 is the devil

  • Too much benzotriazole can harm the delicate highlights of lith

  • Keeping this developer very alkaline definitely makes it fast, but brings with it other problems. Ideal for keeping a differential development rate is somewhere around 12 and definitely less than 13.

  • Too much phenidone also makes blacks less deep and can cause lower midtones to enter infectious development earlier than desired. Ultimately there is definitely a minimum and maximum range, but ideal range is subjective. I prefer for lower midtones to be untouched until blacks are really deep, but this definitely isn’t a universal “best” thing.

  • Despite the problems, this is a very stable lith developer. I decided to leave EXB7 alone for a couple hours and when I came back it was a pale brown and seemed to still have enough life for more printing.

Magic Lith Prototype Update #3

No pictures this time because the results have been pretty boring. Basically, I’ve found that a magic lith formulation can be a lot more flexible than expected, with the primary requirement being a relatively high amount of hydroquinone and a relatively high pH. I’ve done some tests with alkaline prebaths. This seems to help the evenness of a print significantly, but comes with it’s own problems. The print can’t be rinsed after the prebath or else it returns to hardened form and will develop unevely. If the prebath is too alkaline and/or soaked for too long, the print will have a mottle-like effect, but will develop evenly otherwise and quite quickly with the low contrast image appearing rather quickly and then infectious development occurring throughout the print. If done properly the print can also be pulled more quickly and thus with more color. Thus far my best results have been with 2.5m with 1.5L of water + 15ml of 3% hydroxide.

I’ve changed to using a larger tray and 2L of developer at a time which seems to help the evenness as well as tray life but is not a complete solution.

Benzotriazole is an essential component in this developer. Without it, you will get both peppering and yellow staining on the border. With ~5ml/L both will go away. Too much seems to make the uneven development problem worse though.

Bromide is not as terrible as expected. I don’t really understand, but it has more effect in a carbonate based developer than a hydroxide developer, even if both are around the same pH. Iodide is optional.. I can’t really see a huge effect when it is present with bromide, even with a large amount of iodide. With very small or no bromide it does work as a restrainer of sorts, but not a good one.

HQ amount is still a bit of a mystery. More HQ will produce better blacks, but also cause more overall development. High amounts of HQ will produce some fogging with long development times and thus if higher contrast is desired, then going close to the normal print time (rather than massive over exposing) will produce a low contrast image which will then be affected by infectious development to produce proper blacks and darkening of low mid tones.

Ortho Litho/PFS Experiment Report Nov 15, 2019

No fancy pictures because all I used was a step chart and enlarger.. but did test and find out a number of things.

  • PFS-4 mixed with photographic grade TEA (ie, clear not yellow) is not as potent. Seems to require double the working strength and 25% more time for equivalent results. It does seem somewhat more stable to use with photographic TEA with less fogging, but actually looks to lose ~1/2 stop in unstable speed compared to technical grade TEA. Timing and such could potentially be adjusted further with pH balancing

  • PFS-4 as a stock solution seems to keep pretty much forever. The batch I mixed in August is still just as good today

  • PFS-4 can not be replaced by a simple carbonate+bromide solution. It’s clearly the TEA itself that is doing something to the film, not just having a basic environment with bromide present

  • The “stable” speed increase of Arista Ortho Litho with PFS-4 is ~2 stops. The unstable (ie, can be fogged/show artifacts) speed increase is ~3 stops.

  • PFS-4 is effective on Kodalith, though to a much lesser extent. The speed of Kodalith with nothing special is about 2.5 stops faster than Arista, and PFS-4 only adds 0.5-1 stop extra, though does seem to degrade the highlights somewhat and thus resulting in a more pleasant tonal scale, rather than going very dark on the negative, they go to a more mild grey. End result is that the speed of Kodalith with PFS-4 roughly matches that of Arista, but with a steeper contrast curve.

  • PFS-4 does NOT work on Kodak positive microfilm (ie, what FPP sells). Absolutely no difference is made between the two. Also, a fun fact people don’t mention is that it is blue sensitive only and can be processed under red safelight, maybe even amber safelight