I want to thank Karl for showing use his results and formula for PC-512. I also want to really thank Alan for doing want I wanted to do in the beginning of this thread, and that was using Sodium Metaborate (Kodalk) vs Borax. I mixed up a batch of PCM-18 glycol and developed a roll of film out of an old Zeiss folder and must say it worked perfectly using HC-110's 1+47 times. Actually, I used a dilution of 1+50 instead of 1+47. It seems to have a very good balance as to grain and sharpness. Some people think they have to have the sharpest (edge definition) negatives to make an excellent print. I'm not one of them! I like well defined, smooth negatives with good detail and this developer seems to deliver it. At least it did with that roll film folders uncoated Zeiss lens anyway. I might have different results using one of my fancy SMC coated Takumars on my Pentax 67.
I want to thank Karl for showing use his results and formula for PC-512. I also want to really thank Alan for doing want I wanted to do in the beginning of this thread, and that was using Sodium Metaborate (Kodalk) vs Borax. I mixed up a batch of PCM-18 glycol and developed a roll of film out of an old Zeiss folder and must say it worked perfectly using HC-110's 1+47 times. Actually, I used a dilution of 1+50 instead of 1+47. It seems to have a very good balance as to grain and sharpness. Some people think they have to have the sharpest (edge definition) negatives to make an excellent print. I'm not one of them! I like well defined, smooth negatives with good detail and this developer seems to deliver it. At least it did with that roll film folders uncoated Zeiss lens anyway. I might have different results using one of my fancy SMC coated Takumars on my Pentax 67.
Hey John, glad you got something you like! Glad to have helped make something people are enjoying.I want to thank Karl for showing use his results and formula for PC-512. I also want to really thank Alan for doing want I wanted to do in the beginning of this thread, and that was using Sodium Metaborate (Kodalk) vs Borax. I mixed up a batch of PCM-18 glycol and developed a roll of film out of an old Zeiss folder and must say it worked perfectly using HC-110's 1+47 times. Actually, I used a dilution of 1+50 instead of 1+47. It seems to have a very good balance as to grain and sharpness. Some people think they have to have the sharpest (edge definition) negatives to make an excellent print. I'm not one of them! I like well defined, smooth negatives with good detail and this developer seems to deliver it. At least it did with that roll film folders uncoated Zeiss lens anyway. I might have different results using one of my fancy SMC coated Takumars on my Pentax 67.
I want to thank Karl for showing use his results and formula for PC-512. I also want to really thank Alan for doing want I wanted to do in the beginning of this thread, and that was using Sodium Metaborate (Kodalk) vs Borax. I mixed up a batch of PCM-18 glycol and developed a roll of film out of an old Zeiss folder and must say it worked perfectly using HC-110's 1+47 times. Actually, I used a dilution of 1+50 instead of 1+47. It seems to have a very good balance as to grain and sharpness. Some people think they have to have the sharpest (edge definition) negatives to make an excellent print. I'm not one of them! I like well defined, smooth negatives with good detail and this developer seems to deliver it. At least it did with that roll film folders uncoated Zeiss lens anyway. I might have different results using one of my fancy SMC coated Takumars on my Pentax 67.
John, which film did you use in the Zeiss? Thanks!
Adox HR-50 has high resolution but also a high contrast in mid-tones:
To develop this I read off 9m 20C for HC-110 1+63 from the massive development chart and reduced this time by 20% giving 7 min 20C for negatives taken under sun/shade contrast developed in PCM 20 1+63.
This is as per post 377.
The resultant negatives were of rather low density but had the full range of contrast. Here is a scan:
Quite close using HC-110 times.
At box speed?
The only darkroom accident I ever had (so far, knock on wood) was with propylene glycol. I heated it in a microwave a container that was ill-suited for it, and long story short, it pretty much exploded and some globs of hot glycol landed on my arm. No permanent damage or anything, but it was annoying for a couple of days. It helped that I always mix small quantities of stuff like this; in this case it was a small 50ml batch. Lower volume = lower impact if something goes wrong.
Careful with glycol. I now prefer to heat it (if I need to, which isn't often) au bain marie, so in a hot water jacket. This is pretty much safe.
Adox HR-50 has high resolution but also a high contrast in mid-tones:
To develop this I read off 9m 20C for HC-110 1+63 from the massive development chart and reduced this time by 20% giving 7 min 20C for negatives taken under sun/shade contrast developed in PCM 20 1+63.
This is as per post 377.
The resultant negatives were of rather low density but had the full range of contrast. Here is a scan:
Quite close using HC-110 times.
Karl - because you asked (not because my shots are anything special by any means):
Here's a shot or two fwiw from walking with my new-to-me RB67 and pistol grip... which works better than I'd have thought. Shots with PC512 in the title are the ones I'm referring to and used Delta 400 with an Orange filter at adjusted box speed (effectively ISO 100). Scanned with an Epson 850 and Silverfast HDR 9 and cropped/keystoned in DxO software.... 'cause it's easy and I use it for Fuji digital.
For Fomadon Excel or Kodak Xtol the curve speed is just over EI=200 at gamma=0.6.
I think it has this reputation that the true speed is around 200, it's what I have used.
Yes, it’s 200 speed in everything but Foma’s special developer. I always shoot it at 200.
This is the formula using dimezone-s and 18g metaborate:
DCM18 one shot concentrate:
Propylene Glycol...........................80ml
Sodium metaborate.....................18g
Ascorbic acid...................................12g
Dimezone-S.....................................0.7g
Propylene Glycol to.....................100ml
It can be made in a container partially immersed in hot water. The
ingredients dissolve with stirring at 60C ,with some effervescence around 50C.
For use dilute 1+49 with tapwater.
Provisionally, only tested for Delta 100, develop for the time given in the massive development chart for HC-110 or Ilfotec-HC, either diluted 1+47.
Results for a trip on a sunny day are shown, a wide range of subject brightness is captured. I don't have a densitometer.
The gold standard for this type of proprietary glycol based developer concentrate, the only one left, is Ilfotec-HC.
DCM18 may not have such a long shelf life as it contains some water of crystallization from the metaborate.
I have mixer that looks similar to that. Mine tends to get too hot even on the lowest setting. So I have to turn the heat on and off.I heat PG on a lab mixer/hotplate like this one, with a thermometer supported by the upper bracket to keep an eye on temp and make sure it does not go overly high:
www.amazon.com/gp/product/B07FP8J8YV
This both serves to elevate the temperature of the mixing medium and also provides continuous stirring as you're adding the various chemical components. I didn't know that I needed one of these until I got one. Best money spent.
Obviously, you need to use the proper kind of glass to heat in this or you can get very bad glass shattering. Also, and without exception, eye, hand, and body protection should be worn and good lab technique observed.
It has been over a year since I mixed my first batch of PC-512 Borax, and I kept a small amount of Part A unused, stored in a 100ml amber chemical bottle.
I used some the other day and the results seem to be the same as when it was first mixed. Not an especially scientific test, but I will be happy keeping Part A up to a year in future.
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