Pyrocat HD Development Times¶
The suggested development times are guidelines. Increase or decrease development if prints have too little or too much contrast.
Assumed dilution: 1:1:100 (Part A + 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 |
Times at these temperatures should give an approximate contrast index of 0.56, measured with a densitometer in blue mode, for printing on VC silver paper.
Extreme Minimal Agitation (EMA), Tank¶
Tank used: SP-445 daylight tank
- Used for 5×4 sheets in an SP-445 daylight tank (495 ml of solution) at 70°F (21°C)
- Suits FP4 and HP5. For Delta, reduce times by 5 to 10 per cent
- The schedules give agitation and rest intervals for development levels N, N+1 to N+4, and N−1 to N−6. Each level sets A and B values plus timed agitate and rest intervals
Author: Ian Barber, Digital Black and White Revision: 11 November 2026
- Dev: type of development. N is the normal level, and N + and N − levels step development up or down from it.
- A: amount of Solution A, in ml (added to 495 ml of water).
- B: amount of Solution B, in ml (added to 495 ml of water).
- Agitate to: agitate the film until this time.
- Rest to: once the agitate time is reached, let the film rest until this time, then agitate again at the next Agitate to time.
| 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 |
Semi-Stand Development, Tank¶
- Expose at half the film's rated ISO to preserve shadow detail
- Use Pyrocat-HD at 2:2:500 dilution
- Agitate for the first 70 seconds, then for 10 seconds every 10 minutes, for 45 minutes in total at 20°C (68°F)
- The author says this suits FP4+ and Tri-X
Time and Temperature Conversion¶
A chart for adjusting times at temperatures other than 20°C (68°F). It is useful for any film and developer combination.