Question about Jobo tanks

[rdenney]

While at Glazer's last week in Seattle, I had the opportunity to actually lay hands on some Jobo tanks and reels, and it sparked an interest I'd hoped was dead. When I last processed sheet film, I did it in deep tanks using hangers, but in those days I had a real darkroom.

I'm sort-of pondering what the possibilities might be if I used a daylight tank. But the only daylight tank available back in the day was the Yankee, which was worthless.

But I see a lot of discussion around Jobo tanks, and having held one in my hands, think it's probably a pretty good alternative. But I'm getting lost in the numbering and what it all means.

I looked at a short tank that would hold a single 2509n reel (which seems to be the standard 4x5 reel). The tank was, I think, a 2521, which was just tall enough to hold that one reel. Can that combination be used for inversion, like an old Nikor or Paterson tank? If not, can it be rolled? How many sheets does that reel hold? Can the reel be loaded wet? In a changing tent?

Rick "utterly unfamiliar with the Jobo line and appreciating a primer" Denney

[gari beet]

Hi Rick, are you processing B/W? I am assuming so with reference to the tanks.
I have this setup, among others, for developing E6. tThe reels absolutely have to be dry or the film just sticks and won't load but you can get away with the drums being a little wet/damp. Loading is fine, the problem is that if you are loading in a tent or bag everything else risks getting wet. I load in a bag when on the road if I am carrying my Duolab with me, no problems.
As for inversion, I don't do it but I can't see why not, a few caviats, it takes alot chemistry to fill, around 600ml off the top of my head(I am away from home so can't check) so for colour it would be very expensive to do it this way, not to mention the difficulties of tem control. Other than that I see no real issue( boom boom!!).
If you are doing colour a processor is the way to go.
Having used Jobo for a few years I am very happy with the stuff, I actually process halfplate as single sheets in an old print drum which I roll by hand in a tempered tub.

Hope this helps.
Gari

[rdenney]

Hi Rick, are you processing B/W? I am assuming so with reference to the tanks.

Yes, correct assumption. I should have said so and didn't.

When I did it before, I rather came to the conclusion that temp control was as important for black and white as for color, except that you can use room temperature (and that's a big exception, of course). The thermal mass of the larger amount of liquid will help there.

I don't see myself in production mode, so waiting for the reel to dry is probably okay. But then one curiosity--can you stack negatives in the reel back to back?

Did I get the product numbers right? Are there better choices in their line?

Rick "who will have little enough volume to not worry too much about being wasteful" Denney

[Brian C. Miller]

I have the two-reel tank that takes the 2509N reels. I have only used it with a Jobo machine. For using it with inversion, I would first place the reel in the tank, and fill up the tank so it covers the reel. Then pour that off into a beaker and measure the actual level. I think the chemistry quatities are for rotation. You'll also need a cap for the tank, too, otherwise you'll have chemistry coming out.

[domaz]

The reels absolutely have to be dry or the film just sticks and won't load but you can get away with the drums being a little wet/damp. Loading is fine, the problem is that if you are loading in a tent or bag everything else risks getting wet.

The 2509n reels load just fine wet. Not dripping wet- but you don't have to be reiligous about getting them dry before loading like you do with rollfilm reels. I load the reels by hand though- maybe loading with the loader is a different story. I actually pull the film from the front and bend it from the back to get it to load in the channels in the reel.

[Sal Santamaura]

...I looked at a short tank that would hold a single 2509n reel (which seems to be the standard 4x5 reel). The tank was, I think, a 2521, which was just tall enough to hold that one reel. Can that combination be used for inversion, like an old Nikor or Paterson tank?...

...As for inversion, I don't do it but I can't see why not, a few caviats, it takes alot chemistry to fill, around 600ml off the top of my head...

Inversion processing of up to 6 sheets of 4x5 in a 2521 tank with 2509n reel requires 1500 ml. It's OK if you're using a highly dilute developer, paying attention of course to the minimum active developer needed per film area. After development, you could transition to rolling for rinse/stop and fix, using much less liquid. It takes 270 ml to cover the sheets with that approach, but, again, fixer capacity must be considered, so more volume could be needed.

...Did I get the product numbers right? Are there better choices in their line?...

Yes, those are the correct numbers. In my opinion, however, you'd be better off getting a 3006 Expert drum, 1509 roller base and transmission fluid funnel. Unless you're an inversion acolyte, the small developer volume and extremely even results from Expert drums are probably worth the increased cost. More aerobic too.

[Sal Santamaura]

I have the two-reel tank that takes the 2509N reels....For using it with inversion, I would first place the reel in the tank, and fill up the tank so it covers the reel. Then pour that off into a beaker and measure the actual level...

That only works for the 2523. With a 2509n in the 2521, the top of the reel is above the open tank's top. Without the cap attached it will not hold enough liquid to cover the reel. Unless one has a clear cap, which Jobo never offered for sale ( ),it's impossible to see what volume just covers the reel. I've determined by trial and error that 1500ml is optimum.

[seabird]

Rick,

For my B&W processing I use the 2551 tank which holds 2 x 2509n reels. (This is the next size up from the 2521).

I only use rotary development and have never tried inversion - I suspect the amount of developing solution required with the 2551 would make the tank uncomfortably heavy.

I dont use a Jobo processor but manually rotate by hand in a water bath using a home-made rotary base (looks like an upside down skateboard). As you say, the thermal mass of the liquid both inside and outside the tank keeps temperatures within bounds for my maximum 10-mins processing times.

Rotation speed is manually judged - a potential weakness of my system. I use Rodinal 1+50 which is sensitive to agitation, but still seem to get consistent enough negatives for my purposes (YMMV).

Each 2509n reel can physically hold 6 sheets of 4x5. Somewhere in the literature Jobo recommended 4 sheets per reel for maximum quality. Others do 6 sheets per reel without problems. YMMV. FWIW I limit myself to 4 sheets per reel (leaving the middle slots empty) for a total of 8 sheets per run (given 2 reels). If I have less than 8 sheets to develop then I load the "empty" slots with already-processed negatives so as not to disrupt solution flows inside the tank (good to know those "mistakes" came in useful for something ). I wouldn't recommend loading sheets back to back.

I load reels in a darkened closet or, at a pinch, in a large changing bag - but not much wiggle room in the latter. There is a fancy loader you can use, but I just do it by feel. IMO its easier than loading 120 film onto a paterson reel.

Two other things to be aware of:

1. The 2509n has two little plastic "wings" that distinguish it from the older 2509. They apparently help with solution flow patterns inside the tank. Some folks use the reels successfully without them. YMMV.

2. There are two types of lid: cogged and rubber capped (no cog). IIRC, The former are designed for the Jobo machines and are denoted by a 3 in the last digit of the tank number e.g. 2553 = 2550 series tank with cogged lid, while 2551 = 2500 series tank with a rubber capped lid.

I've never tried tray/slosher/dunk-tank/orbital deveopment with 4x5 so cant really comment on the relative merits of each. But I CAN say that I am pefectly happy with my Jobo. The things I like most are: daylight processing (once loaded); ease of use (no mess); quality and consistency of results; economical use of developer (with Rodinal anyway).

Hope this helps.

[Brian C. Miller]

Rick, since you are in my local area, would you like to borrow tanks, reels, and loader? I've been using a 3006 expert drum, and the stuff has been idle for a while.

[Sal Santamaura]

That only works for the 2523...

...For my B&W processing I use the 2551 tank which holds 2 x 2509n reels. (This is the next size up from the 2521)...

Oops, thanks for the correction Carey. My "that only works for" comment was intended to refer to the 2551, not 2523.