Processing 2 x 120 on a Paterson reel

Has anybody done this if so is there some pitfalls or tips for loading

rgds
Dusty

I actually did it 2 weeks ago for the first time. Work wonderfully. I loaded the first roll and when I got to the end, I pull the tape loose from the backing paper and folded it over the end of the film. This way the second roll butted up against the tape and did not slide over the first roll. I'm planning on doing this from now on. No sense developing one roll when I can do two. Practice with two exposed rolls first and get the hang of it.

Brian

I do as Brian describes, but push the first film down (around) to the centre before feeding the second film on.

Dave Miller said:

I do as Brian describes, but push the first film down (around) to the centre before feeding the second film on.

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Tried yr method Dave and it worked, thanks for the tip.

Rgds
Dusty

i tape the 2 films base to base and load it as one.
only use it n case of emergencies

I do this as my standard process for 120, as long as I have two rolls that need the same processing time. I load the first roll, push it about halfway around the reel, then start the second roll and attach the second head to the first tail with a small piece of masking tape (cut to fit between the reel plates, in the light, before I start loading). This helps the first film push the second, and keeps the two from overlapping. The one time I tried pushing the first film to the center before loading the second, they overlapped a couple inches and I lost one frame.

Do you need to alter the time as chemicals must have a greater surface area to work on than with 1 film, but in the same volume?

Rob

I use ID11 1+1 and 500mm is enough for 2 x 120films. I was told somewhere ( on this forum maybe ) that 100mm of stock ID11 is needed for a 120 film so 1+1 is OK but 1+3 is not OK

Rob Archer said:

Do you need to alter the time as chemicals must have a greater surface area to work on than with 1 film, but in the same volume?

Rob

Click to expand...

I don't. There is more than enough of the active ingredients in the solution. It's more a case of making sure the reel is covered.

Rob Archer said:

Do you need to alter the time as chemicals must have a greater surface area to work on than with 1 film, but in the same volume?

Click to expand...

The 2x120 in a single Paterson reel, with 500 ml of liquid, has the same liquid volume per film area as 1x135 in a stainless tank with 250 ml of liquid. The same dilutions and times apply as you'd use for the same emulsion in 35 mm. With HC-110, I've had to change dilution from what I had been using with single 120 films in a stainless tank, but that's only because I was using higher dilution for the economy; in most cases, I prefer the results from Dilution F over those from Dilution G. I now use the same dilution for 2x120 that I've used right along for 35 mm.

The issue is whether you have enough developing agent for the film area; different developers have different recommendations. With D-76, for instance, the recommendation is for 100 ml of stock solution per film, minimum, but that means using it 1:1 is still 2.5 times as strong as it really needs to be. With HC-110, you need 3 ml of USA concentrate for each 135-36 or 120 roll; 6 ml of concentrate at 1+79 for Dilution F gives 480 ml, and in fact, I need 500 ml to cover the film, so I use 6.2 ml of concentrate (I can't measure accurately enough to deliver 6.25 ml). Rodinal requires 10 ml concentrate per 8x10 equivalent, according to Agfa (RIP); at 1:50, I have exactly that in 500 ml, so should use 1:25 with two rolls in a single tank -- and likewise for a single 35 mm roll in a stainless tank, but the Parodinal I've been using works just fine at 1:50 in both applications.