Don't use DK-50 outside the studio, they said...

Michel Hardy-Vallée

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... because it's not really a good developer to cope with the great outdoors!

I'm kidding a little bit, of course because this kind of outdoors scene actually does not have a large subject brightness range, and is in a way equivalent to a portrait lighting setup.

In other words, as long as you know the kind of light you're working with, what your developer does to your film, and what you want, everything can work.



DK-50 1:1 on HP5+, Rapid-Omega 58mm. Les Escoumins (Québec).
 

bluechromis

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Nice. Anchell and Troop praise it for having excellent gradation. It seemed to me they implied the gradation is a reason to use it instead of typical MQ developers like D-76 despite its more limited ability to cope with wide dynamic ranges. Maybe it's a bit vague what gradation is. Do you have any observations about this?
 

DREW WILEY

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DK50 was once popular with big labs as a budget alternative to HC-110. Doesn't mean it will do everything HC-110 can do; but it looks easy to batch up from scratch.
 
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chuckroast

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In the right dilution and agitation model, DK-50 is capable of spectacular results ...
 

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Vaughn

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8x10 (4x10 neg) film developed in straight Dektol. Carbon print.

I use Ilford Universal PQ Developer from 1:9 to 1:19 (paper to film dilutions, depending on the SBR) more often these days. A little experimenting and printing can give one a good idea of the possibilities of a film/developer combination. But the proof is in the print.
 

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Paul Howell

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Until recently I keep a gallon of DK50 mixed up for 4X5, Foma 400 and 200, gain not an issue, accuance was good, and the tones are excellent. I think acutance was better than D76. Not sure if large labs used Dk50 as a budget alternative to HC 110, DK 50 predates HC 110. When in the Air Force we had DK on hand for LF work, I think the tech orders specified DK 50 for LF, but many bases did not always the tech order and used D76. My only grip with Dk 50 is the short development times, I had found replenisher online, but using stock development time was 3 1/2 mints, I found myself using 1:1 or 1:2 at 6 mints.
 

Lachlan Young

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Kodak intended HC-110 to be used as a replacement for DK-60a & DK-50 in many graphic arts/ industrial uses - not on the basis it was 'better', but equivalent enough in qualitative ends that its advantages in terms of large scale usage, replenishment, storage etc would be useful - all the things that matter very little unless you are using the stuff by the tens of gallons day-in-day-out.

Anyway, the Kodak suggestions for HC-110 substitutions for DK-50 are as follows:

DK-50 stock = HC-110 dilution C
DK-50 1+1 = HC-110 dilution D
DK-50 1+2 = HC-110 dilution E

In other words, there are widely disclosed formulae that'll do the same job (possibly better for certain aims) as HC-110...

And as for the old canard about things like DK-50/ HC-110 supposedly being sharper than D-76 - they aren't, but they do deliver higher visual granularity levels, which when there are sequential MTFsystem failings may deceive people into confusing higher levels of visual granularity with real & measurable/ perceivable sharpness.
 
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chuckroast

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I've used DK-50 1:3 as well as 1:5 with 0.5g/l of lye added for very long standing development. In both cases, an initial 2min continuous agitation is followed by a 15sec agitation at 31min and the film pulled at 60min.

The 1:5 variant with lye added will give you high acutance but it may also make grain objectionably visible. The one thing about all this is that if you're going to stand the film for a long time, getting proper shadow exposure
is critical. I use box speed for my EI but I make sure I really am metering for the darkest shadows I care about to end up 2 stops below meter indicated (Zone III). Well, when I do that, I get good negs. When I don't, I get trash

I use these as one shot so replenishment is not an issue. When I was using DK-50 at 1:1 and reusing it, I just used fresh developer to replenish. I never had an issue.

These days, as I continue to explore long, dilute development schemes, I increasingly gravitate toward Pyrocat-HD 1.5:1:250 with 2min initial agitation and 10 seconds agitation at 21min and 41min, pulling at 60min. I just did a roll Kodak Double-X this way and the sharpness under loupe is just astonishing, not to mention how it handles the dynamic range.
 

chuckroast

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Really nice. Well seen and well executed!
 

chuckroast

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I'm not sure what you mean by "visual granularity levels", perhaps you might say more on this?

Almost any solvent type developer can be made to deliver higher acuity negatives by higher-than-usual dilutions. I've taken D-23 out to 1:9 (adding 0.5g/l of lye to maintain alkalinity) and it produces very, very sharp negatives. However, in smaller formats especially, it also really makes the grain pop - objectionably so, to my eye. I've not tried it, but very high Rodinal dilutions are reported to do the same thing.
 

pentaxuser

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chuckroast said:
I've not tried it, but very high Rodinal dilutions are reported to do the same thing.
Click to expand...

Chuckroast I have seen recent videos by John Finch of Pictorial Planet fame and his conclusion with actual prints that he produced was that 1+200 was better than 1+ 100 which is what most use for stand-development

Given your interest in the benefits of forms of stand-development it might be worth a look if you haven't already done so

I never know where the distinction comes in terms of what is termed stand-development when it migrates to semi-stand

pentaxuser
 
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chuckroast

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Stand: Agitate for a bit at the beginning and let the film sit there with no further agitation until done.

Semistand: Agitate at the beginning and again halfway through the standing period.

Extreme Minimal Agitation (per Steve Sherman) - Agitate several times during the standing period. There are lots of approaches to this as far as total duration, dilution, and agitation frequency.

I've done all three. Stand works but cannot reliably avoid bromide drag in my experience. Semistand works reliably.

EMA also works reliably and give the best looking overall sharpness and edge effects. This is a good thing in most cases. However, if you are working with a subject that is highly textured, this can give you a kind of gritty graphic arts look that may not look great.

Films also matter here. I get the best results (so far anyway) with Tri-X, FP4+, Fomapan 200, Efke, and Double-X. I get meh results with Agfapan 100 and Arista 100. I am still learning how to properly do this with Adox CHS 100 II. The results with Plus-X (yes I still have some) seem to vary by what generation of film it is. The really old stuff I have here (from the 1970s) works great in D-23 but bromide drags like crazy in Pyrocat-HD. Go figure.

BTW, the more I do EMA with Double-X, the more impressed I am by this combination. It's just razor sharp and holds dynamic range in very impressive ways.
 

ags2mikon

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Many years ago I had a publication that was printed in the mid 60's that described in detail why you as a large photo finisher would benefit by switching to hc-110 and quit using dk-50 and dk-60a. First was ease of mixing hc-110 was much easier because of it being a liquid. All of the dilutions listed for hc-110 were to match dk-50 and dk-60a dilutions. The other reason was that borates were a concern of the citrus industry in CA and FL. When I built my first darkroom in 1969 the pharmacy my parents used processed black and white film on site and they had changed to hc-110 and he gave me a bunch of cans of dk-60a and told me how to use it. Of course being young and inexperienced and hooked on photography magazines I thought I should use a more "modern" developer and got rid of the dk-60 and switched to Edwal fg-7. My negatives didn't improve. But the costs went up.
 

Vaughn

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chuckroast said:
Really nice. Well seen and well executed!
Click to expand...

Thank you. It was so windy on top of Fort Point (typical for the Golden Gate) I thought for sure it would not be sharp.

Andrew -- ever use D-19 with HP5+?
 
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Michel Hardy-Vallée

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In another thread, I've posted some homemade curves made with HP5 and DK-50 using a Dektronics densitometer, and my overall observation is that you're trading off midtones contrast for better highlight contrast. This gives an upswept tone curve rather than the more typical straight or s-curve patterns. If you like Tri-X 320 (TXP), you'll recognize the look.

Other than that, it's pretty sharp, and easy to use once you know its characteristics. I use it replenished in a 2L jug, so it's always ready to use.
 
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Michel Hardy-Vallée

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In my replenished setup, I do 5:15 at 20C for HP5+, dilution 1:1.
 

Paul Howell

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I dump my diluted developer, never used the replenisher, in the end both the stock and replenisher went south from age. I just don't develop enough film. Now if I was shooting 8X10.
 
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Michel Hardy-Vallée

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ags2mikon said:
Very nice Michael. Have you used it with other films yet?
Click to expand...

It's a developer for 120 and above. I tried it once on 35 mm and regretted the results! Essentially, you need a film with good shadow details like HP5+ because you will lose some.

- I tried it on some old Verichrome Pan I had laying around and caught a serious case of nostalgia. This is a gorgeous match, it gives rich tones and sharpness, and it just seems... better?
- I also tried Fomapan 100, and it's pretty good.
- I got some interesting results on Ilford Ortho, but you have to be careful of the highlights.
- Tri-X 400 will work, but it's a film with less shadow details than HP5+ so you will lose more.
- Fuji Acros worked, but it did not impress upon me.
- I didn't like the results in Delta 400 (a film that's way better in XTOL).
- Nor does it work on FP4+ because the highlights are just blown (inherent S-curve + extra highlight contrast = crap).
- Wasn't keen on PanF+ either, but I have never figured out PanF+ anyway, so maybe it's just me.

Given current film availability, I would recommend DK-50 1:1 with HP5+ and the Foma/Arista films as the best matches.
 

Lachlan Young

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Very simply, it's how strongly you perceive the relative granularity of the film - and what you are seeing with very dilute D-23 is not what you think - it's actually development inhibition effects from exhaustion of Metol. Phenidones are even more extreme in their potential effects, but unlike Metol, they don't shut down their inhibition effects when HQ or similar are added. High solvency levels also release significant amounts of development inhibiting byproducts from the emulsion (iodide & bromide) - and this is where a system that has poor sharpness at its optical/ perceptual steps will fail, because the stages that should be transmitting perceivable sharpness with low levels of loss aren't doing so - and thus the lower granularity is perceived as less sharp than some thing that is significantly higher in visual granularity. Long story short, solvency matters - as do development inhibition effects. Compensation behaviour directly links to inhibition effects, so the effects attributed to Rodinal in stand development are almost entirely nothing to do with inhibition effects, but merely development to a much lower contrast index via developer exhaustion/ oxidation (limited buffer capacity). If it was really producing compensation effects, it would deliver a tone curve like XP2 Super in C-41.

pentaxuser said:
his conclusion with actual prints that he produced was that 1+200 was better than 1+ 100 which is what most use for stand-development
Click to expand...

If he normalised for actual density range, effective film speed etc, I think his results would be closer than his ability to tell them apart. The effective reduction in achievable density between 1+100 and 1+200 dilutions of Rodinal and its impact on granularity should be very, very obvious to all but the most grossly naive.

There are very good scientific reasons why Rodinal was a research dead end - you can beat it dead with PQ, carbonate buffering and the right levels of solvency, improving all 3 of the sharpness/ granularity/ shadow speed triangle.
 
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