Luminous Landscape Forum

Equipment & Techniques => The Wet Darkroom => Topic started by: EinstStein on December 16, 2019, 12:45:35 am

Title: Pour chemical into Paterson 8-reel tank: 4X longer than 2-reel tank, problem?
Post by: EinstStein on December 16, 2019, 12:45:35 am
Compare to the 2-reel Paterson tank, it takes 4X more time to pour in chemical into the 8-reel tank.
The bottom roll will start to develop (much?) earlier than the top rolls. Of course when pour out, it is reversed.
Is this a problem?

Suggest the best practice? 

 
Title: Re: Pour chemical into Paterson 8-reel tank: 4X longer than 2-reel tank, problem?
Post by: Martin Kristiansen on December 16, 2019, 01:36:07 am
Well yes. In the old says fussy people like myself would only use two or single roll tanks. More work but if you want to be fussy there you go. A 2 minute presoak, with water at 20 degrees of course, helps as it slightly slows down and evens out the developing time when putting in the dev, or so we believed in the old days. Remember to add about 45 S to your developer time if doing this.

In reality all you will see, if you see anything at all, is the bottom roll will have a minuscule increase in contrast and an even smaller movement in ISO. Paper contrast should be more than capable of compensating. If you are scanning and going to PS then even less issues.

What I didnít like with large tanks was I Seemed to get an increased risk of air bells. Commercially I helped run a dip and dunk machine for large volumes. Personally I used small tanks. I had four double tanks and two singles. I would run multiple timers and process 8 rolls at a time. Takes a bit of practice.
Title: Re: Pour chemical into Paterson 8-reel tank: 4X longer than 2-reel tank, problem?
Post by: smahn on December 16, 2019, 03:04:20 am
Compare to the 2-reel Paterson tank, it takes 4X more time to pour in chemical into the 8-reel tank.
The bottom roll will start to develop (much?) earlier than the top rolls. Of course when pour out, it is reversed.
Is this a problem?

Suggest the best practice?

Depends how anal you want to be about it. You could fill your tank with developer first. Then load the film onto the reels and rod. With the lights off, plunge the loaded rod into the already filled tank, then cap it and start your inversions.

If you want to eliminate the time of the pour out, you could have a second tank ready full of stop bath. With the lights out, pull the loaded rod from the developer and slam it into the tank of stop bath.
Title: Re: Pour chemical into Paterson 8-reel tank: 4X longer than 2-reel tank, problem?
Post by: Ken Bennett on December 16, 2019, 07:08:36 am
We used to do exactly that -- had 8-reel tanks set up with chemistry, and inserted the film into the tanks in the dark. We only used 7 reels, though, as we'd lose some chemistry at the top on the second or third round.

This is actually worse for the bottom reels, as they are in the developer longer both going in and coming out. But for newspaper/wire service work, no one would ever notice.
Title: Re: Pour chemical into Paterson 8-reel tank: 4X longer than 2-reel tank, problem?
Post by: EinstStein on December 16, 2019, 02:02:13 pm
Using longer develop time should help. This implies to change the developer dilute ratio and changing the look of the picture, such as using HC100 E, F or H instead B. But this will be a different game.

Maybe this is actually a double benefit, to explore more micro-contract!

Or, simply live with the minor variation across films , to stay with, say, HC110B.
Title: Re: Pour chemical into Paterson 8-reel tank: 4X longer than 2-reel tank, problem?
Post by: smahn on December 16, 2019, 10:36:53 pm
We used to do exactly that -- had 8-reel tanks set up with chemistry, and inserted the film into the tanks in the dark. We only used 7 reels, though, as we'd lose some chemistry at the top on the second or third round.

This is actually worse for the bottom reels, as they are in the developer longer both going in and coming out. But for newspaper/wire service work, no one would ever notice.

Sure, about 2 seconds longer. Figure 2 sec going in and 2 sec coming out = 4 sec. But then when hitting the stop bath the bottom go in 2 sec sooner than the top, so all told = 2 sec more. It's beyond negligible, IMO.
Title: Re: Pour chemical into Paterson 8-reel tank: 4X longer than 2-reel tank, problem?
Post by: EinstStein on December 17, 2019, 12:46:08 am
With Paterson 8-reel, the difference is about half minute.
Your gravitation might vary!
Title: Re: Pour chemical into Paterson 8-reel tank: 4X longer than 2-reel tank, problem?
Post by: smahn on December 17, 2019, 07:45:57 pm
With Paterson 8-reel, the difference is about half minute.
Your gravitation might vary!

Not when we're talking about jamming the loaded rod into a prefilled tank. No gravity involved.