Kodak HC-110 Dilutions and Volumes for Sheet Film Processing in JOBO 2550 Tanks and Poilot Reels

Kodak HC-110 is a concentrated developer that can be used at several dilutions, produces good results at full film speed, and lasts for years when stored well. It’s a good, economical choice for sheet film developing in tanks using continuous agitation.

Poilot is a Chinese manufacturer of film developing tanks and reels. Their P2550 tanks are copies of the JOBO 2550 tank and by all appearances completely interchangeable. Their developing reels (the PL-system) seem to be their own design and made for the 2550 tank. The PL-system reels are modular and can be configured for 4×5, 4×10, 5×7 and 8×10 inch sheets, and with modification for Whole Plate 6½x8½ inch sheet film.

TLDR: for the most even and consistent development, get a roller base, use continuous rotary agitation, and use the chart below to determine the amount of developer and solution volume you need.

Ultimately I tried rotary continuous processing using a manual roller base, which typically needs only 300ml to 600ml of developer and takes less than 15 seconds to fill. This results in extremely even development without a pre-wash.

I have made a chart for the 2550 tank and PL-system reels that calculates the volume required for the most efficient use of developer.

As a bonus, the development times for Shanghai GP3 100 film using continuous agitation are listed in the table below.

To use the two tables:

1. In the first chart, select the row corresponding to the film format and number of sheets: example, 3 sheets of 5×7.
2. The chart indicates that for 3 sheets of 5×7, 8.0ml of HC-110 concentrate is needed, and it can be processed in dilutions of 1+39 or higher. (The dilution of 1+31 is not available because the solution volume would be less than the minimum of 300ml.)
3. Use the bottom chart to determine the time and temperature to develop the film: development times shorter than 5 minutes are not recommended. At 22˚C we would use HC-110 1:39 for 7.0 minutes. The 8ml of HC-110 concentrate would be diluted with water at 22˚C to make a total of 320ml developer solution.

Note that the minimum volume precludes some combinations from being used. It’s not recommended to process only one or two sheets of 4×5 film in the minimum amount of developer, you’d need to process them with developer for three sheets at 1+79 dilution and 360ml total. (Similarly, one sheet of 5×7 cannot be processed.)