unicolor dev of 5x7 - actual volumes?

Hi all,

So I'm about ready to try 5x7 development with a unicolor drum. I got an 11x14 and an 8x10 drum, so I'm good to go for either 2 or 4 sheets at a time (and yes, these are the print drums).

My question has to do with how much volume to put in there. I've read various posts and it's unclear. I've also heard about oxidation of the developer, especially when using Rodinal.

Any tips? If you got an actual # that you're using now as to how much liquid, that would be great.

allan

I use Jobo drums but the ideas are the same.

1) You need enough chemicals to cover the film. This is no different then for prints.

2) You need enough chemicals to actually develop the film.


Now choose a volume that is greater or equal to the above two numbers. In other words it's not just the drum that matters. The developer you are using will matter also. I use D-23 diluted that means I need quite a bit of developer. A lot more then the drum itself needs.

The Jobo 11x14 requires at least 100ml of chemicals to cover the prints. The 8x10 is 60ml. I don't know about the unicolour but it's likely in the same ballpark. Won't hurt to use extra.

I use 250ml of d76 1:1 for 4 4x5's in my unicolor setup. I have used the same for 2 5x7's as well. Haven't used the larger drum. I sue the same amount for stop and fixer as well.

Hope that helps.

Thanks. the main point is that I can do this at least somewhat empirically, by pouring some in and looking at it with some kind of clear cover (saran wrap?) on the side or something.

But no comments on rodinal oxidizing before development is done? Cool. That's what I've been using in trays.

allan

Chaska said:

I use 250ml of d76 1:1 for 4 4x5's in my unicolor setup.

Click to expand...

Yep, same here - 250ml in the 8x10 print drum for sheet film.

nsmith01tx said:

Yep, same here - 250ml in the 8x10 print drum for sheet film.

Click to expand...

Ditto. I measured how much developer I could pour in before it overflows the fins that hold the film (paper drum.) 250ml is the max. So as long as the drum is level, I can pour in developer and it doesn't make contact with the film until rotation begins.

This is meaningful to me when using HC110B because dev time is very short, so I want it to be well controlled. I also use D76 1:1 and don't appear to have exhaustion issues with either developer. I always do one shot developing of 4-4x5.

hey all,
thanks for the input. so the tests went okay. 250ml worked out fine. some questions:

-in my very quick test (didn't dev for too long, and didn't fix enough), I noticed that the fins/ridges left marks. how do I get rid of those? Was it just too short a dev time and it would've eventually been okay?

-why are you trying to not get the dev onto the film until rotation begins? it's not like you pour in the dev, wait like 10 minutes and then start rotation, right? so if a bit gets on the film it's okay, isn't it?

allan

Good Morning, Allan,

Could the marks be leftover anti-halation backing? A very short processing time might lead to that. Using a water pre-soak for two or three minutes would probably solve any such problem. As to the time at which the developer hits the film, I'd suggest that it's generally irrelevant, particularly with B & W film. Developing times are usually 5 minutes or longer, so a few seconds one way or the other probably won't make any visible difference. Most of the drums we use for processing sheet film were originally made for processing color prints; the timing there could be more critical, so the drums are generally designed to hold the solution away from the film (thinking of the Cibachrome drums in particular) in some manner until the drum is in a horizontal position on the roller. Your drum also probably places the film somewhat away from the bottom portion when the drum is in position to be filled; the result is a reservoir area along the bottom. When rotation starts, the film comes in contact with the solution, but usually not before. I've used drum developing times as short as two minutes (Kodak Commercial Copy Film) with no problems either with anti-halation retention or uneven development, but I always use a water pre-soak.

Konical

Hey Konical,
I did use a water presoak, but, as with the other steps in this test, not for very long.

I am fairly confident at this point that doing a "real" run will work out right. Doing a test with 30s of presoak, 1 minute of developer and 3 minutes of fix probably isn't a perfect indiation. But it's a pretty darn good one from what I see, considering how impatient I was.

I just need to dial in the times, but I have a couple of sheets that I like less with which to work.

Also, how do you do the wash? I use the Ilford method for paterson-style/steel tanks with 35mm and 120. Should I fill it and let it rotate for 30 s 3 or 4 times?

allan

Good Morning Again, Allan,

I use hypo clear after fixing, dump it, then use a couple of changes of water with the drum rotating. My wash is in a 20 x 24 tray using a Kodak Tray Siphon. I have a couple of flat, acrylic sheets with pins which separate the four 4 x 5 films; this eliminates damage during the wash cycle by keeping the sheets securely fastened. The acrylic sheets were originally designed for dip and dunk processing using large tanks. I purchased mine from Calumet at least twenty or twenty-five years ago; they have not been in the Calumet catalog for many years, and I've never seen any listed on E-bay. If I recall correctly, similar hangers were also available from Calumet for both 5 x 7 and 8 x 10. Making your own wouldn't be extremely difficult, but those I purchased are designed so that solution can easily reach the base side of the film, something which might take a little ingenuity with a home-brew copy. With enough changes of water, I suppose that adequate washing could be done in the rotating drum, but it would be more labor-intensive. By the way, my drums are Chromegas; they've worked reliably and without leaking for several decades.

Konical