Help me get started with tray development! Temperature control?

[welly]

Hey guys,

I've cleared a bit of room in my bathroom and found a folding table which I think will make a perfect table for trying out tray developing sheets. I actually got given a bunch of darkroom bits and pieces, including three Paterson trays. It looks like the trays are slightly larger than 8x10 - at least a box of Ilford 8x10 paper fits in the tray, a little snug but it fits. Would this be suitable for 8x10 sheets or would I really need a larger tray to give the sheets a bit of space?

So obviously the basic process that I've been doing with developing tanks is the same, which I'm fine with. How do you keep the temperature consistent throughout the development process? What about agitation methods? Any advice on this? How many sheet can I/should I develop at a time or should I be developing a single sheet at a time?

I think that will do for now, will add more questions as I think of them!

Cheers,

Welly

[Brian Ellis]

You can probably get by with that tray for 8x10 film (I assume that's what you're processing). I used an 11x14 tray but a tray slightly larger than 8x10 will probably work o.k. You just need to be sure you have enough room to grasp the film when you move sheets from bottom to top of the stack.

Agitation methods are up to you. I moved the bottom sheet in the stack to the top throughout the development process. When I completed one cycle I lifted each corner of the tray up and down once to jiggle the developer, then went back to moving the sheets from bottom to top until the cycle was completed again, etc. etc..

I started out with one sheet just to get a feel for the process. But that's obviously very time-consuming. I eventually got up to 6 sheets at a time though I never did get rid of the occasional scratch. The number of sheets didn't seem to matter, I could scratch one out of two as easily as one out of six though I was able to keep scratches to a minimum. I kept track of which sheet was which by counting, so that I could give different sheets different times in the same run.

FWIW, tray processing for me was the worst way to process film. It keeps you standing over trays inhaling chemicals for 10-15 minutes at a time, it keeps you totally in the dark until the film hits the stop bath (some people wait until it's in the fix though that isn't necessary), it led to occasional scratches on the film, keeping track of which sheet is which is kind of a pain (assuming you don't process all for the same time), all in all I just didn't care for it. Obviously others differ but I switched to BTZS tubes for 8x10 which I liked a whole lot better.

[welly]

Cheers Brian. I thought I'd give it a go just to see what the result are like. Whether it'll be my development method of choice is yet to be seen.

I've got a Jobo CPA2 processor which I'm hoping/planning to use for the majority of my developing but after firing it up for the first time today, I'm finding the accuracy of the thermostat is pretty off the mark (20c is closer to 22.5c), which is a bit disappointing. I'm going to do some more testing with that before I commit to it. I'm hoping it'll all work out because it seems like a potentially simple way of developing.

[Greg Blank]

Due to the mechanical nature of the CPA's temperature knob (Really just connects to a fancy rheostat) 2 degrees and 1/2 is very good for that specific machine. They were only really designed for Back and white processing. The CPP2 machines on the other hand use IC comparators to regulate the temperature- so the CPP2 is more accurate- though I have seen a few that are almost that bad before I tweek them.

Cheers Brian. I thought I'd give it a go just to see what the result are like. Whether it'll be my development method of choice is yet to be seen.

I've got a Jobo CPA2 processor which I'm hoping/planning to use for the majority of my developing but after firing it up for the first time today, I'm finding the accuracy of the thermostat is pretty off the mark (20c is closer to 22.5c), which is a bit disappointing. I'm going to do some more testing with that before I commit to it. I'm hoping it'll all work out because it seems like a potentially simple way of developing.

[tgtaylor]

I've got a Jobo CPA2 processor which I'm hoping/planning to use for the majority of my developing but after firing it up for the first time today, I'm finding the accuracy of the thermostat is pretty off the mark (20c is closer to 22.5c), which is a bit disappointing. I'm going to do some more testing with that before I commit to it. I'm hoping it'll all work out because it seems like a potentially simple way of developing.

That's why Jobo includes two therometers with the unit: one for B&W (in degrees F) and the other for color (in degrees C). Whether I am processing B&W or color I fill the unit and rinse bottles with water that is about 4 degrees cooloer that the processing temperature. For example, 64F for B&W. I then immediately mix the developer. I keep developer stock (Xtol) in floating lid tanks in the bathroom and is at the ambient temperature of the room. I usually dilute the stock 1:1using the same tap water that I filled the tank with (I bring a 2 liter graduate to the bathroom with me to mix the developer, fix, and HPC with) as long as the resulting temperature of the mixtures is close to (preferably below) that in the unit. Once all the chemistry is in the unit, I wait for the therometer in the trough to reach the desired processing temperature - tweaking the thermostat to edge it along more quickly. Once the temperature is reached for B&W (68) I turn the thermostat all the way off. If the ambient temperature in the room is about the same as in the trough the temperature in the trough will remain dead on at 68F for most of your run. It will start to creep up (or down) with removal of the bottles but that creep doesn't start to occur for many minutes after the developement stage is completed. If the ambient temperature is much higher than the processing temperature, than I place a plastic bottle of frozen water that I keep in the fridge into the far right slot furthest from the developers slot) at the instant the therometer indicates a creep upward, and remove it as soon as it's back on the 68 degree mark. Since the ambient temperature is always much lower that the processing temperature for color it's necessary to occasionally tweak the thermostat upwards but again this is rarely necessary as the critical development time is short and it takes significant time for the temperature of 20 liters of water to raise significantly. So I have found it quite easy to keep the processing temperature in tight tolarance (+- 1/4 degree) of the desired temperature and usually dead on for most if not all of the run. In fact my last run was 2 sheets of 8x10 with a development time of 21.5 minutes for the developer with the temperature in the trough remaining dead on for all steps without the need to tweek.

Thomas

[John Flavell]

I process my 4x5 sheets in 5x7 trays lined up in the bathtub. I find the plastic trays keep the temperature constant throughout the whole process. It is a simple way of developing once you locate a place for everything that makes you comfortable. I also use the same agitation scheme as Brian. Consistency and simplicity will help determine how often to agitate.

I also had access to a Jobo processor but rejected it on the grounds that I wanted the hands-on approach for the whole process.

[welly]

Here's a question. How do you check the temperature when you're in pitch blackness?

[John Flavell]

You shouldn't need to check once you have it set. The great thing about plastic is it won't transmit temperature very well, so the temperature stays the same for me throughout. I only need to check between stacks when the lights are on. It's more consistent than the Jobo.

[welly]

That makes sense actually, I don't need to temperature control my Paterson System 4 tanks when I'm developing 35mm or 120 film and have no problem with those. I'm going to give it a whirl tomorrow and see how I get on.

[John Kasaian]

With B&W film I find that having all my chemicals at the same temperature is more important than nailing the temperature exactly (and keeping it there) so I store my stock solutions in amber glass bottles in the same room (resting on the floor) along with distilled water (for diluting) kept along side. If needed, I'll warm or chill the water before mixing (I use one gallon envelopes) so everything is the same temperature when starting out. Having chemicals "warm up" in the tray hasen't been a problem for me, I suspect because the temperatures remain constant from tray to tray. Of course YMMV.