The Chart: Agitation and Errors

Film Photography & Darkroom discussion

Moderator: Keith Tapscott.

George W. Push
Posts: 5
Joined: Thu Jul 10, 2008 2:43 am

The Chart: Agitation and Errors

Postby George W. Push » Thu Feb 24, 2011 6:16 pm

The big table is a help, but I miss two things:

- Exact description of agitation, which is a very important factor in development.

- A possibility to report errors. I saw times for a film rated at box speed that are shorter than the same film and developer at half the speed. That can't be true.


Ornello
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Re: The Chart: Agitation and Errors

Postby Ornello » Fri Feb 25, 2011 11:10 am

Well there are books to refer to. The method I use for agitation is as follows.

I use Paterson tanks and 35mm film. First, I fill the tank with water at the same temperature as the developer (usually 68F) and let it 'soak' for a few minutes. This allows the emulsion to become wet and helps to prevent uneven development.

After pouring out the water and letting it drain, I pour in the developer (I dilute my developer to attain a developing time of at least 8 minutes (10-12 is close to ideal) , to lengthen development time and help ensure even development) and invert and rotate the tank gently for about 20 seconds, ending with a good thump on the table that I use (please use a think towel to help avoid cracking the plastic). Thereafter, I agitate twice, once per minute, again inverting and rotating the tank gently. The tank should be motionless most of the time. Most errors in agitation are those of excess.

About 30 seconds before the time is up, I pour out the developer and pour in acetic acid stop bath. Do not use plain water; use stop bath.

After about a minute or so, I pour out the stop bath and pour in rapid fixer and fix for the appropriate time.

George W. Push
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Joined: Thu Jul 10, 2008 2:43 am

Re: The Chart: Agitation and Errors

Postby George W. Push » Fri Feb 25, 2011 5:36 pm

Well, that is one method - yours.

The basic problem is this:

- Agitation is important.
- There is no "standard agitation method". Every manufacturer recommends something different.
- Times in the tables are not accurate because they do not mention what agitation was used.

Do you agree?

foolscape
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Location: Portland, Oregon
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Re: The Chart: Agitation and Errors

Postby foolscape » Fri Feb 25, 2011 8:39 pm

Very true. Different developers call for different agitation.

I would also like to be able to add times for push processing an N+ or N- adjustments.

One of the other things that would be very helpful would be the ability to add my own developer info to the "My Times" section. In other words, I'd like to be able to choose a film and add a developer that is not listed in the developers with that film in the chart. For instance: I like PMK with Ilford Ortho+, but I can't use the App for it because I can't choose PMK to add to My Times. Do I have to add the info to the main chart to be able to select it? This is a bit awkward, because my App doesn't update. I was an earlier purchaser.

--Gary.

Keith Tapscott.
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Location: Plymouth, England.

Re: The Chart: Agitation and Errors

Postby Keith Tapscott. » Sat Feb 26, 2011 7:02 am

foolscape wrote:Very true. Different developers call for different agitation.

I would also like to be able to add times for push processing an N+ or N- adjustments.

One of the other things that would be very helpful would be the ability to add my own developer info to the "My Times" section.

In other words, I'd like to be able to choose a film and add a developer that is not listed in the developers with that film in the chart. For instance: I like PMK with Ilford Ortho+, but I can't use the App for it because I can't choose PMK to add to My Times. Do I have to add the info to the main chart to be able to select it?

This is a bit awkward, because my App doesn't update. I was an earlier purchaser.

--Gary.
I'm sure that Jon Mided will answer if this can be done.

foolscape
Posts: 181
Joined: Sat Dec 10, 2005 11:01 am
Location: Portland, Oregon
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Re: The Chart: Agitation and Errors

Postby foolscape » Sat Feb 26, 2011 8:55 pm

Keith Tapscott. wrote:
foolscape wrote:Do I have to add the info to the main chart to be able to select it?

This is a bit awkward, because my App doesn't update. I was an earlier purchaser.

--Gary.
I'm sure that Jon Mided will answer if this can be done.
I'm not sure if I was clear on this point. I didn't mean adding it to the main chart solely on my App, I meant submitting the information for inclusion to the chart on this site, which I've done in the past.

--Gary

Digitaltruth
Site Admin
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Re: The Chart: Agitation and Errors

Postby Digitaltruth » Mon Feb 28, 2011 9:58 am

Most of this discussion seems to refer to the Massive Dev Chart App. To request new features in the App, please use this forum:
viewforum.php?f=4

The Massive Dev Chart is intended to provide starting point times only. The User's Guide & FAQ covers these issues: http://www.digitaltruth.com/devchart.php?doc=faq

Most manufacturers recommend initial continuous agitation of 30-60 seconds followed by 5-10 seconds or 3-4 rotations per minute. Times listed in the chart which do not comply with this methodology have specific agitation methods which are shown in the individual notes for the particular film/dev combination.

If you suspect that there is an error in the chart, then you should either use the online form or contact us by email to report it.
--Jon Mided

Digitaltruth Photo
http://www.digitaltruth.com

Ornello
Posts: 833
Joined: Thu Jan 19, 2006 9:49 am

Re: The Chart: Agitation and Errors

Postby Ornello » Tue Mar 01, 2011 9:28 am

George W. Push wrote:Well, that is one method - yours.

The basic problem is this:

- Agitation is important.
- There is no "standard agitation method". Every manufacturer recommends something different.
- Times in the tables are not accurate because they do not mention what agitation was used.

Do you agree?
If you are talking about 'standard' developers (powder-type developers such as D-76 or ID-11, Microphen, UFG, Acufine, etc., or liquid concentrates such as HC-110 or Ilford liquid developers), this agitation method should work for you. As I said, most agitation errors are of over-agitation. Over-agitation will create streaks with 35mm film. Don't think that agitation is some magic procedure. It isn't. Two gentle inversions once per minute is all that is necessary.

The method I use is basically the same as that recommended by many manufacturers, with extremely minor variations. It is therefore 'standard'. With Paterson tanks it seems to work well. The most important thing is to get the development time up to at least 8 minutes, preferably more. The longer the development time, the more even and consistent your development will be. A 30 second error on a 6 minute development time is more than a 30 second error with a 12-minute development time. One can get a longer development time by diluting the developer more or by adding a small amount of boric acid to the solution. Trial and error will be necessary to get the amount right.


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