Rotary Processing: Does processing 15% less than your tested developing time......

Vetus

Member
Joined
Mar 29, 2023
Messages
55
Location
UK
Format
4x5 Format
Does the advice develop 15% less than your usual inversion tank developing time hold true when rotary processing black & white film?
 

MattKing

Moderator
Moderator
Joined
Apr 24, 2005
Messages
53,305
Location
Delta, BC Canada
Format
Medium Format
Thread title adjusted for clarity and focus.
In answer to the question: it depends!
 

Rick A

Subscriber
Joined
Mar 31, 2009
Messages
9,958
Location
Laurel Highlands
Format
8x10 Format
As MattKing stated. 15% is a starting point, you need to do some testing to get the results that please you.
 

xkaes

Subscriber
Joined
Mar 25, 2006
Messages
4,798
Location
Colorado
Format
Multi Format
Whenever you make a change in your developing process it's essential to test it. Don't just take someone's advise. Produce some test results from the "old way", and then make test results the "new way" -- making adjustments -- until you get them to be the same.
 

Tim Stapp

Member
Joined
Dec 21, 2012
Messages
557
Location
Big Rapids, MI
Format
4x5 Format
Depending upon what type of rotary processing...

Jobo recommended a 5 minute water pre wash prior to developer to use standard inversion times, except for XTOL, for which Kodak published times for rotary processing in addition to inversion.

For films in XTOL that Kodak did not test, I've found JOBO's suggested 5 minute prewash matched my inversion developed films.
 

Sirius Glass

Subscriber
Joined
Jan 18, 2007
Messages
50,415
Location
Southern California
Format
Multi Format
I have not found that to be the case. Often it is too much. Ilford HP5+ and FP4+ require one minute added to the 20°C [68°F] time for the negative to be thick enough to use.
 

Sirius Glass

Subscriber
Joined
Jan 18, 2007
Messages
50,415
Location
Southern California
Format
Multi Format

Ditto
 

btaylor

Subscriber
Joined
Dec 28, 2010
Messages
2,258
Location
Los Angeles
Format
Large Format
When using my Unicolor Film Drum I would run a 1 minute pre-wash and then use a 15% reduction from inversion agitation time. Worked fine, I did not feel the need for any further testing.
I don't recall the developer, it was likely a generic equivalent to D76.
 
OP
OP

Vetus

Member
Joined
Mar 29, 2023
Messages
55
Location
UK
Format
4x5 Format
Are there any film developers that are less efficient when used in a rotary processor? I'm guessing that using stock developer
Undiluted or 1+1 works better than highly diluted chemistry, am I correct? If it depends on developer choice, which developer do you favour for rotary and why?
 

Sirius Glass

Subscriber
Joined
Jan 18, 2007
Messages
50,415
Location
Southern California
Format
Multi Format

XTOL and replenished XTOL with most of the developing done with the latter. It provides better shadow detail, finer grain and better sharpness than the other developers. Plus the tonality is better and I have found that the developer is the most forgiving developer that I have every used. [Translation: one can f**kup and the film is still printable.]

 

Steven Lee

Member
Joined
Jul 10, 2022
Messages
1,438
Location
USA
Format
Medium Format
I am not sure about the "efficient", but the spec to watch here is developer capacity. Rotary processing usually requires far smaller volume of chemistry per roll, so if you're diluting too much you risk developer exhaustion.

Another variable is developer activity. For example, the manufacturer of Ilfosol 3 insists on 1+4 dilution, but it's just too damn active in that form, so I wouldn't consider it for rotary processing.

My thinking on the subject goes like this:
  • If possible, avoid rotary for B&W because it doesn't offer the same compensation effect as intermittent agitation, and excessively aerates the developer making reuse/replenishing more difficult.
  • If forced to use the machine, I prefer developers with flexible dilutions and use higher ratios. My favorites are Xtol or Ilfotec HC. I suppose HC-110 also belongs here.
 

xkaes

Subscriber
Joined
Mar 25, 2006
Messages
4,798
Location
Colorado
Format
Multi Format
In short, whatever you decide to do, test it.

I use rotary processing for 4x5 -- B&W and color -- and inversion tanks for roll film, and I ran tests for both. That's essential.
 

Tim Stapp

Member
Joined
Dec 21, 2012
Messages
557
Location
Big Rapids, MI
Format
4x5 Format
I use rotary processing for everything on my JOBO CPE+. 35mm, 6x7 and 4x5. I use XTOL straight with Arista EDU 200 primarily.

With a 5 minute presoak, 6 minutes develop and stop/fix/wash (three times, five minutes each) times my negatives turn out great (for me and my methods).
 

cowanw

Member
Joined
Aug 29, 2006
Messages
2,236
Location
Hamilton, On
Format
Large Format

I think you will find that Ilfosol 3 is used either 1:9 or 1:14; fixer is commonly 1:4.

"ILFOSOL 3 is supplied as a liquid concentrate normally diluted 1+9 for one-shot use. Dilute it immediately before use and discard directly after development. For greater economy it can be used with many films at a higher dilution of 1+14 with only a small trade off in image quality."

Also regarding Ilfosol and rotary development.

"Without using a pre-rinse, the given development times will need to be reduced by around 15% to compensate for the continuous agitation."
 

Sirius Glass

Subscriber
Joined
Jan 18, 2007
Messages
50,415
Location
Southern California
Format
Multi Format
Vetus said:
Does the advice develop 15% less than your usual inversion tank developing time hold true when rotary processing black & white film?
Click to expand...

RalphLambrecht said:
not in my experience.I just use the straight unmodified time.
Click to expand...

I have the same experience. None of the times needed shortening, but two Ilford films needed more time.
 
You must log in or register to reply here.
Menu
Log in
Register
Cookies are required to use this site. You must accept them to continue using the site. Learn more…