paul_verizz

This is amazing, an almost new thread about DK-50! In 2015 for reasons I don't remember, I decided to make and try DK-50 on Plus-X 1:1. I was beyond blown away! What grain there was, minimal and tight. Nothing like one would expect in theory. Great tonality. Where have you been for the last 65 years?

At the time I was very much involved with APUG, which I see has rebranded itself. I did some posts there which you may find of interest. Anyway, about then I had to move and here it is 2019, ready to get back to film and developing. So I've been going through all my records and notes and internet searching as I get ready to go down the rabbit hole again.

Elliot, you observations about being equal to T-Max times will be a life saver. Development times has been the bottleneck for DK-50, for sure. I have printed out the pages from the Massive Development Chart filtered for DK-50, and all films for T-Max developers. BTW, that motorcycle image is stunning, right on what I got with my short lived experiments.

I also started experimenting with DK-50 in a divided format; god, I've been a slave to the idea of divided development for 40 years.

My original post on APUG: DK-50, Still alive and well?

<p>Where I missed the boat WAS in the math. Maybe my reading comprehension? A lot of developer and other threads aren't the best written, although Patrick Gainer's tend to be good. And then with every tweak someone wants to use, or the dilution rate, the details get lost, like that old campfire game of telephone.<br>

Reading back through my saved pages again, I realized that the 5g carbonate added in Gainer's PC-Glycol was after being diluted to the equivalent of 1:3 Xtol. Looking back at my chart in Haist, it became obvious that I would need about 40g of Kodalk for an equivalent pH.<br>

I took 50ml of my working strength PC-K, but with the 5.1 pH, added the equivalent of that 40g/liter, and got a pH of 9.8! More importantly, my daylight test snippet of TMX is developing well.<br>

Yes, I know how sodium metaborate is derived. Personally, I'd rather just take it from a jar.<br>

I also noticed that Xtol has a high level of sodium sulfite, so there is already quite a bit of alkalinity to counteract the sodium ascorbate even before the metaborate is added.<br>

Thanks for the feedback, peter!</p>

<p>@Peter, I thank you for taking the time to respond. I know what is theoretically needed, which is why I'm alarmed at such a low pH. I've gone over the mixing math several times, admittedly not my forte, but I think I'm good in that department. <br>

I've no concern about minerals because A) they aren't in my tap water here, and B) I need to solve the pH issue first. I might just start over, it's all cheap enough. </p>

<p>About two years ago I was going to take the ascorbic acid developer plunge. I collected quite a few intertube pages and kept them. Also around that time I mixed up a PC/water concentrate, using the classic 1:40 ratio of Phenidone to Ascorbic Acid. I tossed it into my freezer and forgot about it. <br>

<br />Fast forward, got tired of everyone with $1K and a digital camera is now a "photographer." ("What's an f/stop?") Got my old Ricoh's fired up, took film out of the frozen and lead lined vault, and am now shooting for test color neg which I'll process, and conventional B&W. <br>

I thawed out my PC concentrate and tested the pH, 3.1. (Digital meter, zero'd with pH 7.0 calibrating lab water.) I put 60ml of that into the beaker, so now I have .15g Phenidone and 6g ascorbic acid. I decided to go with 4.5g Kodalk for the alkali. I came up with this from Michael Madio' experience with 18g borax, using my extensive references to equate about 4:1 borax:Kodalk for an equivalent pH.<br>

The pH is only 5.1! <br>

Gainer suggests 5g sodium carbonate, that should, again per above Haist reference, less than a 2:1 difference from Kodalk. Yes, I understand that's significant, but since I'm only at pH5.1, I don't even see an over ph7 on the horizon! And these matters are not linear.<br>

So, does ascorbic acid work at a much lower pH? I've seen no reference to pH of the developers. Xtol uses a reasonable quantity of Kodalk. Am I missing something? <br>

FWIW, the Haist reference refers to research that shows equivalent densities from 1 unit of sodium hydroxide, 3 of sodium carbonate, 5 of Kodalk, or 20 or borax.<br>

Sure, I'll try a test strip in daylight, but I thought I'd shout out.</p>

<p> </p>

<p>The first question one needs to ask is, "What quality level do my images need to be?" Yes, the DSLR setup gives better results, but if all you are going to do is print to 8x10, to pick an example, it doesn't matter. If you never print larger than 8x10, a 3.3mp camera will provide 300lpi "photo quality." Not talking cropping, of course.<br>

If your images are more on the line of family memories, such detail as the author has achieved is not necessary. For my slides and 35mm images of memories or history, I scan them at 2400dpi. That still gives "almost photo quality" for an 8x10. <br>

Of course, if you have commercial or art images, go for the quality! You think I skimped on my father's 35mm and 4x5 1930's and 1940's Kodachromes? Not hardly! <br>

Some of the reason for the difference in results might be that consumer flatbed scanners are limited to about 1200 sensors per inch on the bar, IIRC. At least, that was the state of the art not long ago. That means that without interpolation or stepping motor travel of anything less, the maximum whole pixel image that can be attained is 1.44mp over a given square inch! Or, about 2mp for a 35mm slide. That flatbed scanners get up to 9600 dpi ratings is due to stepping motors of fine degree, software that does amazing interpolation, and of course, marketing hype. The differences in a scanner rated 1200, 2400, 4800, or 9600 dpi is just in the stepping motor, one is always stuck with the 1200 dpi across the bar.<br>

The idea of using a digital camera for "scanning," BTW, precedes DSLR's. But with fixed lenses it's hard to get quality. Focus differences across the image and lens distortions.<br>

So, bottom line, yes, it's technologically logical that a high megapixel DSLR will give better results than a flatbed scanner at a 1:1 image ratio. A nominal 12mp camera in 3:4 ratio mode, allowing for some cropping from the 2:3 35mm ratio, will give 2700 pixels on the short side, already better than the flatbed 1200 native by well over twice.<br>

If you can use the performance of a Ferrari, go DSLR. If you will be stuck in rush hour traffic, consider a Chevy.<br>

My last thought is this: In scanning memory/history images, it's rather nice to set up a rack of 8 or 12 slides, make corrections, and then go mow the lawn...........</p>

<p>Thread a bit old, obviously, but if I may contribute.<br>

I grew up in the era of street photography, Royal Pan-X, and Strobonar. Not that I could afford the latter. <br>

Maybe about twenty years ago I picked up this model at a photo swap meet, I'm guessing. Ah, like the old guy in the Corvette that makes him young? <br>

I grew to love this unit, to the point that I bought another as backup. I got all the Strobodomes and AC power supplies. While TTL metering or dedicated flash control is ideal, most photos probably don't need that degree of control. <br>

Time goes by and I coupled it to my Minolta digital cameras. Talk about tech dichotomy! Yet, the photos I took indoors with the diffuser Strobodome are stunning! <br>

Recently I pulled my primary unit off the shelf and it didn't work! With further testing, nor was the AC unit working! My generic bad luck? But just with computers, back up, back up, back up. So now I'm on the, um, back up unit and AC charger. <br>

And I will most certainly be trolling eBay for a backup to it. <br>

My Konica-Minolta built in flash recently stopped working. Dead-ola. But the PC connection still triggers. I have a huge photo inventory project of family assets in front of me, and the old Strobonar plus diffuser will give me salvation.</p>

<p>I've been organizing and scanner the many pounds of negatives from my father and sometimes his. Both were pro's.<br>

I have a couple of hundred of 4x5 negs, I estimate. About 1/3rd or less of them are seriously deteriorated and unusable. My research indicates that the turning blue, the bubbling, the delamination, and the brittleness all indicate acetate base. They are from about 1944 to 1960 (not sure if any of the late ones are deteriorated, but the earlier ones sure are.)<br>

No signs of brand or edge printing. My father most used Kodak through his photo career, but I've seen Ansco and DuPont in papers.<br>

Oh, BTW, you should see those 4x5 Kodachromes! Wow, stunning, still!<br>

Not that it matters at all, but I'm just curious what film this might have been. The only thing that sets the deteriorated ones apart from still perfect ones is the notch code. It is two rectangular notches 7/16" apart, edge to edge.<br>

I love a good photo mystery.<br>

Thanks for any help.<br>

Paul</p>

<p>I just tried to make a simple post and when I submitted it, this is what I got. Oh yeah, clear as mud: </p>

<h2>Problem with Your Input</h2>

<p>We had a problem processing your entry:</p>

<ul>

Because of abuse by spammmers, we can't accept submission of any HTML containing any of the following tags: <code>applet area base body button div embed fieldset font form frame frameset head html iframe ilayer input layer link marquee meta object option pre script select span style textarea /applet /area /base /body /button /div /embed /fieldset /font /form /frame /frameset /head /html /iframe /ilayer /input /layer /link /marquee /meta /object /pre /script /span /style</code>

</ul>

<p>Please back up using your browser, correct it, and resubmit your entry.</p>

<p>Gosh, maybe I was right. According to this thread Dimezone is indeed a Kodak product. http://leica-users.org/v31/msg02476.html<br>

The poster also says 20% less active than Phenidone, I guess your mileage may vary.</p>

<p>I wonder why you aren't getting full ISO with a developer type that often gives greater than box speed. </p>

<p>Another possibility is that despite many lovers of no-sulfite PC, sulfite remains useful to open up development centers in Xtol and maybe is not so much a silver solvent. Especially at dilutions which would put sulfite in the working strength of about 20g at 1:3. Not sure why you put 6g in your Part B at all.</p>

<p>Let me throw into this discussion the patent formula, verbatim: (I've noticed that many patents have missing commas and other formatting issues. Like this one, why would the "0.2g" of Dimezone be inserted into the chemical name????? Ditto the acetic acid.<br>

Part A (Dry Formulation) Sodium sulfite 10 g, Diethylenetriaminepenta- 1 g acetic acid (water softener???), pentasodium salt Sodium metaborate (8 mol) 4.0 g, 4-Hydroxymethyl-4-methyl-1- 0.2 g phenyl-3-pyrazolidone (Dimezone)<br /> Part B (Dry Formulation): Sodium sulfite 75 g Sodium metabisulfite, 3.5 g Sodium isoascorbate 12 g</p>

<p>End result:<br>

<br /> 85 g Sodium Sulfite<br /> 3.5 g Sodium Metabisulfite<br /> 12 g (Sodium) isoascorbate (Sodium Erythorbate)<br /> .2 g Dimezone S<br /> 4 g Sodium Metaborate (Kodalk)<br>

I presume the Sodium Metabisulfite is a pH adjuster. While a preservative like its sulfite cousin, at this amount it doesn't matter. I believe Dimezone is used instead of Phenidone for easier dissolving. Or maybe Kodak has the patent!</p>

<p>Does your house have a different source of hot water than cold? What with all your geothermal sources there, it wouldn't surprise me. If your house is like 99% of the world though, your water is of the same make up, cold or hot.<br>

Is your film worth the cost of distilled or RO water? Mine always is. Especially so with ascorbate based developers, they are very sensitive to metals and self-destruct on oxygen like a suicide bomber.<br>

I've read for years on the internet about the oxygen permeability of PET and polyethylene bottles. Until I see some scientific, not anecdotal or outta duh butt, evidence that oxygen moves from the air through the plastic with a zero pressure differential, I'm a skeptic. Of course glass is always the "take no chances" best, and I'd bet that these new synthetic corks don't pass air. Probably not the screw caps, either, but I've never bought anything with that low grade type.......yeah......</p>

<p>Scott, I must be having a major brain synapse malfunction. Forgive me Great Yellow Father, for I have sinned. Apparently slipped a decimal cog. Thanks.<br>

Reworking my calcs for a 1:50 dilution, that's still sort of weak. Obviously not so much as I thought, but still weak. Two grams of AA is the same as Xtol at 1:5, although the Phenidone is double what is believed to be in Xtol. (I've read the patents, but there is so much of "In a range of" that someone with greater skills and equipment must determine that actual point. A formula "for Xtol" that I copied - oh, damn, using my brain again - has 85g sulfite, 12g ascorbate, .15g Dimezone, 3g sodium metabisulfite. I don't recall the source, but it looks good insofar as the patents.) If we can say that Dimezone and Phenidone are roughly equal in activity per weight, then Patrick has doubled the Phenidone per Ascorbic Acid. Again, there is about a 90% equivalence between AA and the salt, nothing that would make quantum leaps of effectiveness. <br>

You said, "I think the problem is that the additional AA dropped the pH of the solution and caused it to become inactive." I'm not sure sure that happens. I mixed some AA with sulfite, I think 12g and 60g accordingly, and the pH was a smidge under 7. I was shocked, I expected a lot lower. Maybe the sulfite did some coupling with the AA to make ascorbate, I dunno. But I"m down other roads now so that will just have to remain a mystery.<br>

I'm going to take Gainer's PC-Glycol using the AA as a comparative to Xtol, and start from there. I'll use metaborate for the alkali as Kodak does for Xtol, and add sulfite to equivalence, too. Maybe I'll have chance this weak to try out. Nothing fancy, no densitometers, just eyball and an 8x loupe.</p>

<p>That's the original story I mentioned. 100g AA.<br>

If we mix up separate PC, Sulfite, and accelerator, the combinations are endless. <br>

I've never heard anyone complain about Xtol grain or sharpness being mushy, so despite Mr. Gainer's horror at using sulphite, that's where I'm heading. If nothing else, sulfite opens up development centers in the silver bromide grains which normally translates into increased speed. </p>

<p>Boy, that Google bot gets around! Here I am doing some research on PC-Glycol and it picked up your new post.<br>

I mixed up some Phenidone based PC the other night; I've not had a chance to try it. I used Prestone antifreeze for the glycol. I had spent a lot of time agonizing over getting pure stuff by mail, but the Prestone specifically states no borates, no silicates, no other things which I remember being in antifreezes long ago. The only ingredients besides ethylene and diethylene (?? IIRC) glycols are two sodium salts which I presume to be the metal protectorants. From my amateur chemist perspective, neither sound photographically active.<br>

So laying out Phen/AA/SS/Kodalk quantities from what is presumed to be the official formula for Xtol, and then PC, I discovered a major difference at working dilutions. The reason I want to stick near Xtol is that Kodak already did all of the time-temperature work, dilutions up to 1:3 on the German chart. No sense reinventing the darkroom.<br>

If one uses the amount of ascorbic acid/ascorbate in Xtol 1:3, we find, still, 3 grams of AA. Using the 10g of AA in - and this is critical - an often quoted PC-Glycol formula, there is only .2g!<br>

Note also that Gainer uses, at 1:50, less working chemicals and more pH, using carbonate instead of Kodalk. At 5g/l, that's a big pH difference. But hard to see it making up for 1/15 the AA.<br>

So happening to come across - again - Gainer's original article about preservation of AA developers, he concludes that the mix should be in a glycol, and then he gives his little simple formula: .25g Phenidone (still a lot more than Xtol, in all probability) and 100g AA! Ten times as much as the formulas floating around elsewhere. That would give 2g at 1:50. The "missing" gram from Xtol might be substituted, in effect, by the higher carbonate pH.<br>

I am gong to internet research this discrepency some more, and in all probability will add a lot more AA to my PC-Glycol! I also think that Kodalk/Sodium Metaborate/Kodalk Balanced Alkali was used in Xtol for a reason, that being a better buffered solution. Carbonate has no buffering ability.<br>

Paul</p>

Just for some grain objectivity, the RMS granularity for 5222 is 14. Smack in the middle of Plus-X's 10 and Tri-X's 17. The sharpness is off a tad from Plux-X, 110 vs. 100, but you would probably never know it.

The difference in human perception to RMSG numbers is that about a 16% differential becomes noticeable. So, from 10 to about 11.6 (12?) is noticeable to the typical sujective observer. Thirteen and 14 is probably two orders of magnitude.

Speaking only in terms of granularity and sharpness, 5222 would be identical to Foma 200. But look at that price!

Late to the conversation.....

Frank, those RMS grain numbers for TMY are incorrect. The old version of TMY had a rating of 11. The new one is 10, just like Plus-X. No way is a T-Max of a given speed grainier than the conventional films. Otherwise, why bother?

B&W movie films are also made by Ilford. Surely the Chinese, too. Fuji? Don't know.

I had that same Freestyle 5222 back when. Still have some film cans that I marked as XX.

Assorted opinions.....

1. I noticed, too, on a new box of TMY-2, no development information. I guess they save a half a cent a box times a few million, and anyone developing knows where to find that info. Not like Lucky, or something.

2. Ferrania, AFAIK, hasn't made a B&W emulsion in decades, see Lester's comment. Ditto for 3M. And even if they were to do so down in OK, wouldn't they use their traditional channels and rebranding before going into the prosumer market?

3. The fact that FS has the exact same development times for so many developers sort of tips the hat. Why 100 instead of 125? A red herring? I dunno.

4. There's no way they could market either T-Max without someone finding out with their first roll. And the development times are different.

5. I was about to order some respooled Plus-X from Ultrafine, now I'll wait to see if I can get the "Made in America" "100."

6. Porter's prices have always been astronomical, although I've bought a lens and a few things over the years. I don't understand how they stay in busines.

7. Don't wait around for Film Emorium to have any 5231 Plus-X short ends. I ordered last fall, they had to refund my money. Yesterday I got on the phone and the guy even "made some calls," but to no avail. 18 cents a foot, bummer.

Plus-X forever......and certainly since the demise of Verichrome Pan!

Film: Verichrome Pan. Oh, wait, Kodak doesn't make it anymore. Lower contrast version of Plus-X, for all practical purposes. Hmmm... Any of the old fashioned grain films, stay away from the Delta and T-Max for the time being. If cost is a consideration, try the Foma/Arista Ultra.edu films from Freestyle. Decent films and the cheapest out there.

Developer: Diafine. You can't mess up. At the very beginning you don't need more challenges than absolutely needed. Diafine and Tri-X @ 1200 is one of those photo marriages made in heaven. Later, dabble with D-76, every film in the world gives developing times for it. If you don't develop much, freeze it, it works just fine! Compare to Diafine. Use D-76 as a single shot 1:3 (25% developer). You might have to poke around for times and/or determine your own.

Paper: Foma/Arista Ultra.edu RC to learn on. Use later for proofin' an' goofin'. Fiber based is so much more difficult and time consuming, save it for later. If you can, buy graded papers to start with so that you don't have to contend with all the VC variables. If you go with VC anyway, use filters and not a color head. KISS. BTW, the Foma/Arista Semi-Gloss is just like Kodak "N" surface, still being made in their color papers. I like it a lot.

My suggestions is taking into account that many of us have always had to live photographically on the cheap and probably holds true for you. Far better to burn up Arista for learning that hesitate to do things because of the cost. If cost isn't a consideration (lucky you!) the door opens real wide.

As you noticed, there are a lot of opinions here. Photography is one of those arts that has no final answer. Welcome to The Matrix!

OK, I've lookd over the spec sheet.

I wouldn't pin exactness on the number of stops pushed or pulled. Developers just don't work so neatly, so linear. But I think it reasonable to have a stronger concentration of chemicals in Bath A result in a higher gamma. I doubt if you'll find a true ISO type speed increase, i.e., down at the toe. More than chemical concentration, it is mostly time that Phenidone needs to find those barely exposed grains and make them pop.

Thanks for the data sheet. I'll have to come back to that when I have more time.

When I mention that dilution is a control with DD's, I was talking generically. Whether you mix from scratch or dilute a stock solution, whatever. Not AB55 in particular.

Presoaks with DD's prevents a full Bath A absorption, in theory. But whatever works.....

Back in the late 80's Freestyle was selling something of your description. It was cheap, slow, and ultra fine grain. I have no recollection of who made it or what it was called. It was obviously being sold as a psuedo-quasi-sorta Tech Pan. As I recall, pretty thin images. But maybe that was my defective technique.

So long ago, so few gray cells.......

Assorted comments:

1. Absolutely amazing! As one who has spent untold hundreds of hours researching, formulating, and testing DD's,

I'm jealous!

2. I looked up the MSDS on Freestyle. Not very helpful. It lists Phenidone (with a typo) and hydroquinone as

ingredients in Bath A in typical proportions for a PQ developer. Nothing at all on Bath B or its replenisher.

3. A replenisher for Bath B????? Very odd, what could it be replenishing if Bath B is the usual alkali and/or sodium

sulfite. Perhaps it's just more Bath B with the intention of preventing increases of developing agents in Bath B,

including bromide. Constant dilution of "contaminents" as it were.

4. Bonifaz, there is no zone control in Diafine. In fact, unless a whole roll is shot under the exact same lighting

conditions, roll film can't do zones with any developer. Two baths enable a wide range of shooting conditions which

can then be adjusted for in the darkroom when enlarging.

5. I'm not aware of any standard terminology for two baths, split, divided, whater. Different folks call them different

things, and I find myself using all of them.

6. Yes, it's important to understand that some DD's do partially develop in the first bath and that can be used for

control. And likewise, some (Diafine, for example) has essentially no development going on in the first bath. Not

understanding this fact has caused untold words and disagreements or misapplications!

7. Agitation in DD's in Bath A for "non-developing Bath A's" is just for fun. OK, get rid of air bells, too. All the film is

doing is absorbing developer and the sodium sulfite is opening up some silver grains for seeding.

8. Agitation in DD's in Bath B is counterproductive. It washes developer from A out and into solution and defeats

some of the compensating factors that make a DD so great. Yet, some agitation is needed to prevent bromide drag

and/or mottling in highlight areas like the sky. I have come to settle on developing with the tank horizontal and a very

gentle roll of 90-120 degrees every 20-30 seconds.

9. The only real controls in DD are dilution and strength of Bath B, the pH. One could customize a DD for a

specific film to perfection if one is willing to spend the effort!

10. DD's were looked at for B&W movie processing way back when the industry was picking up speed. As we

know, that isn't what was settled on, for whatever reasons. Don't forget politics and habit!