My PC-512 Borax Developer

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relistan

relistan

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Hello @relistan, some of the development times listed for PC-512 Borax would be a bit short for hot weather.
Did you ever try it half strength 1+1 with a time increase about 1.25 to 1.3x longer from results with other developers? Just trying to get a time multiplier for 1+1 compared to 1+0.

Hey @Alan Johnson no, I haven't tried that. In Ireland it's more or less never hot! 23C would be a very hot day here. @Andrew O'Neill has some times posted for 1+100 dilution, and it seems to work like that. His times seem like they are 25-50% longer. He can probably comment more. I do not know what effect that might have on the grain behavior. I also don't know what effect using more borax solution and less concentrate will have on the pH. If you mean to dilute with water, but same ratio of borax:conentrate, then obviously the pH wouldn't be an issue.
 

Alan Johnson

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For the case where development temperature is high, I tried developing at half strength (49 Borax soln + 1 PC-512 +50 water). Half strength in this case is not the same as 1:100 ( 99 Borax soln +1 PC-512 ).
An increase in development time of about 80% compared to that for normal PC-512 Borax was found to give a negative density closely matching.
On A3 inkjet prints the grain from both was not detectably different, and fine.
The half strength solution result gave the half strength solution as slightly sharper in this single test.
Above results were for FP4 type 517 cine film used in the test.

At 25 C the time for FP4+ is increased from 4m14s with PC-512 Borax to 7m 38s using the half strength solution.
 
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I used semistand often at my old house, my tap water came out around 26 in winter. In summer I was lucky to keep the house that cool, AC worked to keep it at 29 some days.
 
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relistan

relistan

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For the case where development temperature is high, I tried developing at half strength (49 Borax soln + 1 PC-512 +50 water). Half strength in this case is not the same as 1:100 ( 99 Borax soln +1 PC-512 ).
An increase in development time of about 80% compared to that for normal PC-512 Borax was found to give a negative density closely matching.
On A3 inkjet prints the grain from both was not detectably different, and fine.
The half strength solution result gave the half strength solution as slightly sharper in this single test.
Above results were for FP4 type 517 cine film used in the test.

At 25 C the time for FP4+ is increased from 4m14s with PC-512 Borax to 7m 38s using the half strength solution.

Very good info, thanks for running this test @Alan Johnson ! This might be a way forward for some films with quite short dev times at 20C as well.
 

bernard_L

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Long time watcher of this thread. I had sworn off Silver Bullets; long time user of D-76 1+1. But I was convinced by the positive evaluations. Prepared some PC-512 and developed a short series of pictures. FP4, Contaflex SuperBC, yellow filter. Dev 6'15" @ 22°C (from 7' @ 20°C per Ilford compensation chart).

Taking the film out of the PhotoFlo, I was already impressed by the low fog, the detailed shadows, and the tone separation. Nice negative! Please define? You know when you see one🙃 And after scanning, good resolution and almost no grain (although grain is not at the top of my priorities). Tonality looks all right, although a more qualified statement will wait for enlarger prints.

@relistan : Well done!

LS-2000 scan, just black and white points, no USM.

2025-07-07-c-M.jpg


100% crop @ 2700dpi :

2025-07-07-c-cr.jpg
 

Sidd

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I have tried pushing Tmax 400 to 800, increased the development time by 30%, results are very good.
 
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relistan

relistan

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Long time watcher of this thread. I had sworn off Silver Bullets; long time user of D-76 1+1. But I was convinced by the positive evaluations. Prepared some PC-512 and developed a short series of pictures. FP4, Contaflex SuperBC, yellow filter. Dev 6'15" @ 22°C (from 7' @ 20°C per Ilford compensation chart).

Taking the film out of the PhotoFlo, I was already impressed by the low fog, the detailed shadows, and the tone separation. Nice negative! Please define? You know when you see one🙃 And after scanning, good resolution and almost no grain (although grain is not at the top of my priorities). Tonality looks all right, although a more qualified statement will wait for enlarger prints.

@relistan : Well done!

LS-2000 scan, just black and white points, no USM.

View attachment 401576

100% crop @ 2700dpi :

View attachment 401577

Thanks for posting, this is great! Nice results and I'm glad you are happy with them!
 

Alan Johnson

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On a hot day, FP4 cine film was developed in half strength PC-512 Borax, 1 PC-512+49 Borax +50 water. The time calculated for 20C , 7min x 1.8 =12.6min was adjusted for temperature.



I have found that using the multiplier of 1.8 times also works to convert the time from full strength to half strength PC-512 Borax with HP5+.
 
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relistan

relistan

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On a hot day, FP4 cine film was developed in half strength PC-512 Borax, 1 PC-512+49 Borax +50 water. The time calculated for 20C , 7min x 1.8 =12.6min was adjusted for temperature.



I have found that using the multiplier of 1.8 times also works to convert the time from full strength to half strength PC-512 Borax with HP5+.

This looks really good, @Alan Johnson . Mind if I add info to the data page about developing this way and add this and your other time?
 
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