A little confused with chemistry quantities

[Jacko1729]

This may fall into the DuH category, but since getting my Jobo CP-2 processor I'm just a tad confused. It's kind of like this....

Since 1 liter of E-6 will process 12 rolls of 35mm, my Jobo says to use 240ml of chemistry to process (2 roll tank). In the past, using inversion, I've filled the film tank (about 1 liter, which was the quantity I always mixed) and processed normally, then on the next two rolls, adjust development time to compensate.

The reason I'm confused is, the Jobo instructions say to use 240ml, BUT, if the chemistry data sheet says to use more, then follow the data sheet instructions instead of Jobo's recommendations. The smallest quantity on the data sheet is 500ml, and there is no specific instruction that you can't use less.

Questions...
1) Is 240ml 'one shot' only? If 1 liter does 12 rolls, 500ml should do 6, 250(240) should do 3 rolls. Process 2 the first time, then 1 the last time?

2) Should I just use 480ml (which is supposed to do 6 rolls) and just do 2 at the time, adjusting time for rolls 3-4, and 5-6?

3)Lastly, one data sheet says Velvia should be developed longer than Ektachrome. If that's so, I shouldn't be mixing Ektachrome and Velvia. Are any of you doing this, or what are you doing concerning mixed film brands.

Thanks for your help!

Jack

 

[Roger Hicks]

Dear Jack,

What I always do is 4 rolls in 500 ml, one-shot. Extravagant, in a way, because I get only 8 rolls per 1-litre kit, but it's still cheaper than a pro lab and a LOT quicker. My nearest pro lab is probably 30 miles away and may be as much as 60 (I haven't checked but these are the likely cities). I can therefore spend more time travelling than I do processing, or trust the Post Office (yeah, right) or use a courier which adds a fortune to the cost.

As for Kodak/Fuji, yes, I do separate mine, though the extra time suggested for Fuji seems excessive to me: I give about half as much extra time as they suggest.

Cheers,

Roger (www.rogerandfrances.com)

 

[Jacko1729]

Ahhhh, Thanks Roger! Much, much clearer. I think I'm about ready to give this a go again!

Jack

 

[Roger Hicks]

Dear Jack,

You're welcome.

It's not difficult. Ed Buziak once had a CPE-2 die on him, 3 minutes into the E6 first dev (it was second-hand and ratty when he got it, and he had used it hard for years). He agitated manually for the rest of the process and still got good trannies.

Cheers,

R.

 

[Nick Zentena]

You don't say which chemicals you're using. Follow the chemical company unless they suggest using less chemicals then Jobo does. Always use the larger number.

 

[davetravis]

Remember to add the recommended volumes of every tank that you put together to form a larger tank: 140 + 330 = 470 ml for 4 rolls of 120. Follow the "rotary" volumes. I use the Kodak one shot and measure according to each tank's processing volumes. I go 7 1/2 minutes in the first developer for the Fuji, and get great results. Don't mix Fuji with other films. I found the rotation of "P" to be too much for the 1500 tanks, and use the "4" speed instead. Good luck.

 

[Jacko1729]

Thanks everyone for your replies. I did a run the other night with my new Jobo CPE-2 and processed some E-6. I am tickled at how well everything turned out!

Jack

 

[PhotoJim]

When you rotary process, you can often use less chemistry. I think my Jobo stuff will run with 125 mL (the paper tube certainly will) if you are rotary processing.

My E6 kit is a 500 mL kit that will do 4 rolls, which implies 125 mL per roll. Since that meets or exceeds the rotary development requirements for solution, I should be able to just use 125 mL per roll of 135-36 or 120, as long as I'm not inversion agitating.

 

[Bob Carnie]

When I started with Jobos, I tried to maximise chemicals , for me with a full run of film on it never seemed satisfactory, we switched to full volume on each tank, ie one litre and found all our small problems go away, we have been using full volume since and have not looked back.