Large-format Black&White Film Development with the Paterson Orbital Processor
Since I couldn't find any HOWTO tutorial instructions on how to use this, I thought I'd write-up my routine for others to benefit from, here.
Environment
I use my bathroom for loading and developing films, since it's entirely internal, has plenty of running water (showers are good for removing dust from the atmosphere when drying) and an extractor-fan (since fixer stinks to high heaven).
Equipment
I have a wooden plank the top of the bath, to give me a reasonably large flat work-surface. It helps to have some sort of routine laying-out the equipment before unloading film; this photo shows the bottles of developer and stop-bath, 2 measuring cylinders and a measuring jug, film-holder, thermometer, clips and Paterson ready to go:
The Paterson Orbital comprises 3 components: a large tray, lid, and base:
It is recommended to practice fitting the lid on top of the Orbital, since in the dark it's possible to slide it on slightly skewed. Also experiment with rotating the tray on the base one-handedly using the circular hole on the lid; it should be quite a smooth action that sees each corner dip down in turn.
Obviously it helps to have a clock or timer to count-down the development and time the fix & wash cycles.
Chemicals
You will need:
- developer
- stop-bath
- fixer
- lots of flowing water
It's possible to develop in 250ml of solution (which I normally keep stored in readiness - this way the temperature has days to stabilize), but I prefer to use 350-400ml in the Paterson to be sure it's well covered to a good depth all around.
Temperature
Follow your developer's guide for temperature. In practice, for black and white processing, there's a lot of lee-way but the general idea is for the solution to be at 20 degrees Celsius. If you're making up the developer, mix hot & cold taps to taste. In practice, 16 degrees is too cold, requiring a long extension to development time. You can probably also compensate for extra dilution of developer by running a couple of degrees warmer and/or for a slightly longer time. Routine
Lay out all the equipment as above and turn out all the lights. And the one above the shower power-cord...
Once you're sure it's completely dark, open the film-holder, remove the sheets one at a time and lay them firmly along the bottom of the Orbital processor, one on each side, emulsion-side up (if you pull them out of the holder with the rough corner in the top-right, the side facing you is the emulsion).
Firmly slide the lid on from one side, making sure it clicks into place. You should be able to pick up the whole thing by the circular tube in the middle of the lid - if the bottom falls off in the attempt, you've not done it right!
Once you're sure the lid's firmly attached, you may turn on the lights. Quickly pour in the developer and agitate.
Agitation Technique
Unlike daylight-tank-based 120 or 35mm development, it is possible to agitate too vigorously, especially by swivelling the processor around on its base:
The consequences of excessive agitation are both solution leaking out of the exit-corner making a mess, or the red pegs will come undone, the film sheets will migrate into the deeper middle-part of the processor tray and where they overlap, development will be seriously uneven (eg, the corner of one sheet will show on the adjacent!).
Also, under-agitating the processor will cause development to take much longer, as the film is not regularly exposed to fresh solution.
I had a phase of restricting agitation to only picking up the tray and wobbling it gently along the length. However, this is insufficient - the ripples don't disturb the developer solutions sufficiently, contrast was lacking in negatives processed, and it seemed to require more developer solution per film. What now seems best for me is 10 vigorous rotations on the base at the start of every minute - this needs less solution. After this I knock it fairly hard onto the table-surface from about an inch high, in order to dislodge any air-bubbles on the film-surface (as you would with other formats in a tank).
Stop-bath
Since only a dilute solution is required, I tend to dilute the stop-bath 1:50 in the storage bottle and then a further 1:5 before use.
Towards the end of development, start the shower running and pour out the developer solution. You can expect this to be brown or magenta in colour:
Run 450ml of tap-water through the processor quickly and then pour in the stop-bath. I tend to leave it in there for a minute, using the processor atop its base to agitate quite thoroughly.
Fixer
Pour out the stop-bath and rinse a couple of times with more tap-water.
I tend to store 350ml of fixer diluted 1:10 in readiness.
Agitate enthusiastically every minute for 4-5 minutes.
Final Rinse & Wash
Pour out the fixer. Run a couple of 450ml jugs of water through to rinse it quickly, and then leave the next couple in for a minute whilst agitating to be sure you catch all the fixer solution.
Use PhotoFlo or similar wetting-agent to break the surface tension. You'll need about 10-15ml in 400ml water. Take care not to let it foam-up! Agitate for about another 30s, so all the film surfaces are well covered.
Finally, pour it out and quickly extract the film from the processor and hang it up to dry:
About 8-12hrs later, it should be ready to scan...