Developing Single Reel in Paterson Single or Two Reel Tank

I'm aware that in the two reel tank, you put your single reel on the bottom and an empty one on top, using enough developer to cover the bottom reel.

My question is, using inversion agitation, would it be preferable to use a single tank when developing a single reel? Does the airspace in a double tank affect development time as you invert, or is it insignificant? A double tank would seem to cause more bubbles as well.

Hi Derek
I use a Paterson dual tank to develop one film. As you say, empty reel on top . After each agitation just tap the tank on a work surface to dislodge any bubbles. My agitation is invert tank while turning on its vertical axis. Never had any problems.

Paterson make a locking ring so you can use just one reel in a double or larger tank, maybe it only comes with the larger triple and even larger tanks though.

The air space makes no difference even with inversion agitation, not even with replenished developer.

Ian

This seems to differ for everyone.... but to chip in.

I've had regular problems with agitation drag marks or seemingly uneven development when only using a single spiral in the bottom when developing a single film.

Using a second spiral in top solved all of that and i haven't had any problems since.

YMMV FWIW IME etc

I always develop any 35mm films in a Paterson 2 reel tank, if I have just one film I always put the second reel on the top, but I tend to use 500ml of developer, same as for 120, if for some reason I use 300ml of developer I use the twiddle stick rather than inversion just in case the reels ride up slightly, but \i believe in using a bit more developer than the tank needs,
Richard

If you use an empty reel, put it on the bottom! I just found this out the hard way.

My older Paterson tanks came with a locking ring and I use it with one reel in a two reel tank. Probably a lot of opinions and articles on how much air should be in a tank for inversion agitation. I use 1000ml of PMK with a single reel and that developer to air ratio works for me.

david schaller said:

If you use an empty reel, put it on the bottom! I just found this out the hard way.

Click to expand...

Why on tje bottom, surely the empty reel should be on the top, the loaded reel on the bottom, otherwise you would need 600ml of developer to cover the top reel,

Thanks for the responses everyone. I wasn't aware of the locking ring. This website is great..going to subscribe soon.

If you do not have a locking ring then a rubber band tightly twisted works just as well, \i prefer simply to put the second reel on top, saves a lot of mucking about

Cool..sounds good.

It is a good thing to think about because differences in agitation do have an effect, but the question is - how much effect would this difference make?
Without incredibly precise control of all the other factors - developer condition, temperature, film type, nature of images, etc. - there is probably no way of definitively evaluating and measuring that effect.
My impression - based on decades of using various types and sizes of tanks - is that, given consistent patterns and frequency of agitation, the difference is minimal between developing one roll in a one reel tank with 300 ml of developer (for example) and developing one roll in a two reel tank with some form of spacer and 300 ml of developer. I have lots of reels, so I use them as the spacer.
My Paterson tanks are almost all the latest version Super System 4, which do not come with a locking ring. I don't know whether the older locking rings would work with them - the centre cores seem to have different surfaces. If you can't use an extra reel, I would suggest a stretched and doubled over rubber band.
In my case, In recent years I've been using developer in a replenishment regime. As a result, I am almost always using a 3x135/2x120 Paterson tank, filling it with one litre of developer and putting in what ever number of filled and empty reels as is required. With replenishment, you don't end up tossing away unused developer, because it goes back into the bottle after you use it (less a little bit that is replaced with fresh replenisher).
If I were the OP, I would be more concerned with ensuring that my agitation patterns and frequency were consistent.

I appreciate the detailed response. Consistency does seem key, so it seemed like a question worth asking. I've only ever used single steel tanks years ago. I'll just use the two reel system.

Having an empty reel above the full reel gives space for the developer to mix when inverting, so I believe it is a good thing. Agitation would be minimal if there is no space at all above the full reel.

Having the empty reel on the bottom with the full above, and half full tank of developer can cause dichroic fog from development byproducts--I learned this from experience.