Ilfosol 3 development times for HP5 Plus, FP4 Plus and other films
Ilford's Ilfosol 3 technical information (June 2010) lists times for spiral tanks with intermittent agitation at two dilutions, 1+9 and 1+14, and two temperatures, 20 °C and 24 °C. The tables below copy the rows for the films people ask about most. HP5 Plus at EI 400 takes 6:30 at 1+9 and 11:00 at 1+14, both at 20 °C.
How to read the tables
The sheet prints times like 6.30 and 4.15 without saying what the dot means. I read them as minutes and seconds (6:30, 4:15). A dash in the sheet shows as n/a. Ilford says the times are a starting point for normal contrast (a Gbar of about 0.62), rated at the EI shown, and that you may adjust them to your own contrast preference.
1+9 is the normal one-shot dilution. 1+14 saves concentrate at what Ilford calls a small trade-off in image quality, and its times are longer. For the mL of concentrate and water in your tank, the dilution calculator opens here with Ilfosol 3 1+9 in a 300 mL tank.
Ilford films
| Film | Rated at | 1+9, 20 °C | 1+14, 20 °C | 1+9, 24 °C | 1+14, 24 °C |
|---|---|---|---|---|---|
| Pan F Plus | EI 50 | n/a | 4:30 | n/a | n/a |
| FP4 Plus | EI 125 | 4:15 | 7:30 | 4:00 | 5:00 |
| HP5 Plus | EI 200 | 5:00 | 7:00 | 4:00 | 5:30 |
| HP5 Plus | EI 400 | 6:30 | 11:00 | 5:30 | 7:00 |
| HP5 Plus | EI 800 | 13:30 | 19:30 | 10:00 | 14:00 |
| SFX200 | EI 200 | 6:00 | 9:00 | 5:00 | 7:00 |
| SFX200 | EI 400 | 8:30 | 13:30 | 5:30 | 9:30 |
The sheet also lists Delta 100, Delta 400, Delta 3200 Professional and Ortho Plus. I left them out to keep the page short.
Kodak films
| Film | Rated at | 1+9, 20 °C | 1+14, 20 °C | 1+9, 24 °C | 1+14, 24 °C |
|---|---|---|---|---|---|
| T-Max 100 | EI 80 | 5:30 | 9:00 | 4:30 | 7:00 |
| T-Max 400 | EI 200 | 5:30 | 7:30 | 4:00 | 5:30 |
| T-Max 400 | EI 400 | 6:00 | 10:00 | 5:00 | 7:30 |
| T-Max 400 | EI 800 | 8:30 | 14:00 | 6:30 | 10:00 |
| Tri-X 400 (400 TX) | EI 200 | 5:30 | 8:30 | 4:30 | 6:30 |
| Tri-X 400 (400 TX) | EI 400 | 7:30 | 12:00 | 6:30 | 9:00 |
| Tri-X 400 (400 TX) | EI 800 | 10:30 | 18:30 | 8:30 | 13:30 |
Ilford calls the times for other manufacturers' films a general guide, because those products may have changed over time and the times may need adjusting.
Other temperatures
Ilford allows 20 to 24 °C for Ilfosol 3. For other temperatures, add 10% to the time for each degree colder and take off 10% for each degree warmer. The sheet's example: 4 minutes at 20 °C becomes 3 minutes at 23 °C and 6 minutes at 16 °C. For trays it advises staying at 20 °C, because higher temperatures make the times short and development can turn uneven.
For 22 °C, the HP5 Plus time of 6:30 at 1+9 needs a temperature calculation. It uses a curve fitted to Ilford's chart, so it can differ a little from the straight 10% rule.
Agitation, rotary tubes and trays
For spiral tanks the sheet recommends four inversions in the first 10 seconds, then four inversions in the first 10 seconds of every following minute, with a firm tap on the bench after each round to dislodge air bubbles. Drain the developer 10 seconds before the time is up.
With continuous agitation (a rotary processor, or rocking a tray) the sheet says to cut the times by about 15%. For rotary tubes the 15% applies without a pre-rinse. Ilford generally does not recommend a pre-rinse, because it can lead to uneven development.
One-shot use and films per bottle
Ilford calls both dilutions one-shot developers and does not recommend reusing them or replenishing. Working solution should not be kept longer than 24 hours. A 500 mL bottle makes 16 films of 135-36 at 1+9 or 24 films at 1+14. The reuse calculator therefore has no use here. It suits ID-11 stock or a C-41 kit.
The sheet's tank table gives 30 mL of concentrate and 270 mL of water for 300 mL at 1+9, and 20 mL plus 280 mL at 1+14. It advises against measuring less than 10 mL of concentrate, so a small tank at 1+14 may call for 1+9 instead. The table runs from 100 mL to 2 liters.