Pyrocat HD Development Times
Guidelines
The suggested development times are guidelines. Do not hesitate to increase or decrease time of development over the recommended times if your prints have too little or too much contrast.
Assumptions
1:1:100 dilution of Pyrocat-HD (One Part A + One Part B + 100 Parts Water)
Tank or Tray Development
| Film | EI | 68° F | 70° F |
|---|---|---|---|
| Acros | 100 | 18 Min | 16 Min |
| Delta 100 | 125 | 12 Min : 25 Sec | 11 Min : 15 Sec |
| FP4 | 80 | 11 Min | 10 Min : 45 Sec |
| HP5 | 320 | 15 Min | 13 Min: 30 Sec |
| TMAX 400 | 400 | 15 Min : 31 Sec | 14 Min |
| Fomapan 200 | 100 | 12 Min | 10 Min : 45 Sec |
Contrast Index
These times, at the temperatures indicated above, should give an approximate CI of .56 when measured with a densitometer in blue mode, appropriate for printing on VC Silver Paper.
Extreme Minimal Agitation (EMA) (Tank)
Pyrocat HD has also been used very successfully with extreme minimal agitation (EMA) development.
When developing 5×4 sheets, I use the SP-445 daylight tank which uses 495ml of solution and use the following times.
The following times gives very good results when using FP4 and HP5 films. For delta use 5% to 10% less time. The temperature is based on 70 degrees F or (21 degrees C)
| Dev | A | B | Agitate To | Rest To | Agitate To | Rest To | Agitate To | Rest To |
|---|---|---|---|---|---|---|---|---|
| N | 3 | 2 | 2:00 | 9:30 | 9:50 | 17:00 | 17:20 | 24:30 |
| N + 1 | 3 | 2 | 2:00 | 12:30 | 12:50 | 23:00 | 23:20 | 33:30 |
| N + 2 | 3.5 | 2.5 | 3:00 | 15:00 | 15:25 | 27:30 | 27:55 | 39:00 |
| N + 3 | 3.5 | 2.5 | 3:00 | 21:00 | 21:30 | 39:30 | 40:00 | 57:00 |
| N + 4 | 4 | 3 | 5:00 | 20:00 | 20:40 | 35:40 | 36:20 | 50:00 |
| N – 1 | 3 | 2 | 2:00 | 8:30 | 8:50 | 15:00 | 15:20 | 21:30 |
| N – 2 | 3 | 2 | 1:30 | 6:30 | 6:50 | 11:50 | 12:10 | 16:30 |
| N – 3 | 2.5 | 2 | 1:30 | 9:30 | 9:45 | 17:50 | 18:05 | 25:30 |
| N – 4 | 2.5 | 2 | 1:30 | 8:00 | 8:15 | 14:45 | 15:00 | 21:00 |
| N – 5 | 2.5 | 2 | 1:25 | 6:30 | 6:40 | 12:05 | 12:15 | 17:00 |
| N – 6 | 2.5 | 2 | 1:25 | 5:30 | 5:40 | 10:05 | 10:15 | 15:15 |
Pyrocat HD Semi Stand Development (Tank)
Many developers can be used for this type of non-agitation film processing but at the top of the list, for me anyway, is Pyrocat-HD . This developer can be extremely dilute yet still fully process a film within a few hours.
Expose the film at half its rated ISO. This will ensure good shadow detail. Place the film in the developing tank and pour in the very dilute developer Pyrocat-HD 2:2:500
With Pyrocat-HD, agitate for the first minute and 10 seconds every 10 minutes for a total of 45 minutes at 20 deg. C. This is about right for FP4+ and Tri-X.
Time Temp Conversion Chart
This chart is provided as a quick and easy guide for users who need to adjust development times for processing temperatures other than 20ºC/68ºF. It is a useful guide for all film/development combinations.