For starters, this is how it looks:
At the far edge of the plastic 25L (5+ gallon) bowl is the immersion heater with built in thermostat, at the left end the smallish circulation pump – both bough at an hobbyist aquarium shop – total cost less than 50€. Visible is also the cheap digital thermometer I use.
The remainder are numbered 500ml PET bottles and caps with mixed Digibase C41-kit chemicals, plus the rightmost bottle – plain water. The rubber bands around the bottle necks allows to have them lie down in the water, attached to a clothes peg on the edge of the bowl.
This C41-kit comes with time descriptions for temperatures from 25 to 45°C;
- I have found 15L water in this bowl be just under the limit where the bottles still stand.
As the dev-tank has a bit bigger bottom area it doesn’t stay upright – I have to remove some water before putting it down into the bowl.
- First make sure the water bath temperature is constant, at the the point you have chosen (read out from instructions).
- Read out the times from the instructions. I have chosen to sum up the times; so that I have “time points” where to switch liquids. I jot down these on a piece of paper before starting – see step 6 to understand why.
- Load the film onto the reels in the dev-tank, using either your darkroom-bag or pure “darkroom” (whatever way you may come up with).
- Prepare for drying the film – rope and clothes pegs are the basic equipment, a place in a shower is very good.
- Start a timer, I use an egg-clock counting upward – therefore the summed up times in 2)
- Immediately after, start by pouring in the temperature adjusting water bath (rightmost bottle).
- Place the tank in the water bath, slowly remove excess water to make it stand steadily upright.
- Agitate! (Removes water bubbles for a starter)
- Leave the water in the tank, at least for the prescribed time.
- As there are 20-30 seconds left of the time; pour out the liquid, into the correct container for later liquids (do NOT mix caps or bottles)…
- Have the tank turned upside down to let it drip off a bit, turn it back as you still have enough time to prepare for the next step…
- At the prescribed time point, pour in the next liquid.
- Seal up container and wash up after the used liquid.
- Agitate the tank as prescribed in the instructions.
- For each liquid, repeat from step 11 .
- As the last liquid is in; prepare to hang the film to dry – run HOT water in the shower until there is steam in the room
- As the last liquid has been poured out; hang the film to dry,
- Check that there is no dust or bubbles on the film surface. If there is, make sure to have a minuscule amount of surfactant in water to spray with
- Allow to dry at least one hour and completely tack free, better yet 24h.
Analyzing C41 negative film development: