Agitation during development of 5x4 sheet film

I've shot some sheet of 5x4 FP4 film and developed them in Rodinal (1+50) for 15 minutes at 20C. The guidlines I;ve seen talk about agitation every minute or so, I've used a Jobo drum on a rotator that constantly reverses the movement every minute or so. Does anyone have any guidelines about this? Should I develop for less time as the agitation regime is more often. Maybe I should try some test sheets to determine the standard development times with my set up.

As you can tell, I'm new to this area.
Thanks in advance.

I've found that using 85% of the recommended developing time is a good starting place for continuous agitation. Example, if normal developing time is 10 minutes, use 8.5 minutes for continuous agitation.

The only way to find ideal time for you is to run some tests. It takes 6 sheets and a day of work, but you will KNOW your time for sure.
I've done it last year and I never regretted it. See "Film Test Procedure" at Ralph's site: Dead Link Removed

Rodinal is not recommended for continuous agitation. However I have tried it and it seemed to work. I normally used it 1:50, agitation 10 sec per 60.

Best thing to do is tray develop one sheet and and one sheet in the JObo of the same subject. If you compensate times, you can get them to match. Then compare details such as edge effects and midtone contrast.

I use Rodinal with continuous but very gentle agitation to develop 5x4 sheet film. No problems! I used to use a divided tray but now use a Paterson Orbital without the motor, i.e. agitated by hand.
For Adox CHS 100 my time for normal development is 10 minutes with a dilution of 1+30 (total amount 10 +300mls)

Alan

AlanC said:

I use Rodinal with continuous but very gentle agitation to develop 5x4 sheet film. No problems! I used to use a divided tray but now use a Paterson Orbital without the motor, i.e. agitated by hand.
For Adox CHS 100 my time for normal development is 10 minutes with a dilution of 1+30 (total amount 10 +300mls)

Alan

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As an Orbital user, I am really interested how you do agitation. Which kind of pattern and how often.
I have abandoned the motorized base and now I use Orbital like a slosher, rocking it from each side. Doing two full series of rocking in the beginning of each minute. The one serie is: raise from nearest side, then left, then back, then right.

Usually this gives a good negatives, but sometimes there's a little more density on the edges.
I don't know if it's caused my agitation pattern, speed or something else. I too use 300 ml.

A great set of very helpful comments, many thanks.
I'll definately check out the Darkroom Magic link to understand the techniques to get some repeatability.

I've always run with guidelines the same as Rick - 15% off normal hand agitation times.

Usagi said:

As an Orbital user, I am really interested how you do agitation. Which kind of pattern and how often.
I have abandoned the motorized base and now I use Orbital like a slosher, rocking it from each side. Doing two full series of rocking in the beginning of each minute. The one serie is: raise from nearest side, then left, then back, then right.

Usually this gives a good negatives, but sometimes there's a little more density on the edges.
I don't know if it's caused my agitation pattern, speed or something else. I too use 300 ml.

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I usually rotate it slowly for about 15s one way, then 15s in the reverse direction and so on, on its "rotation" base. Whether using Rodinal (1+50) or more recently PC-TEA (1+50), I always get nice, evenly developed negatives. I try to keep the solution around the 200ml mark.

I do lose a bit of film speed with the continuous agitation, so whereas I would shoot (say) Foma 100 at box speed in 120 format, I'll shoot it at 50 or 64 in sheet film format when developed in the Orbital.

Usagi,
Before I got a Paterson orbital I used divided trays. I often got overdeveloped edges probably due to over-enthusiastic rocking..One day I found there were a few dead flies floating in the water that I had left in a tray. Out of curiosity I decided to find out how little I could move the tray and still get the flies to move around the tray. I found it was very little indeed. Slowly lifting one corner of the tray no more than 5 millimetres caused enough agitation to do the trick. So this has been my method ever since. I have the Orbital on a flat surface, and place a finger under a corner and slowly raise and lower it a few millimetres. I may repeat this once, or twice. Or may do it just once, before moving on to another corner -opposite or adjacent. I follow no pattern, but keep the developer moving slowly and continuously.
Once I tried vigorous agitation for five seconds every half minute -with nothing in between. I got tide marks of uneven development across the negatives. So I went back to continuous agitation. The tide marks were on 5x7 film, and the developer was D76 1+2. Don't know if Rodinal would have done the same.

Alan

AlanC said:

Usagi,
Before I got a Paterson orbital I used divided trays. I often got overdeveloped edges probably due to over-enthusiastic rocking..One day I found there were a few dead flies floating in the water that I had left in a tray. Out of curiosity I decided to find out how little I could move the tray and still get the flies to move around the tray. I found it was very little indeed. Slowly lifting one corner of the tray no more than 5 millimetres caused enough agitation to do the trick. So this has been my method ever since. I have the Orbital on a flat surface, and place a finger under a corner and slowly raise and lower it a few millimetres. I may repeat this once, or twice. Or may do it just once, before moving on to another corner -opposite or adjacent. I follow no pattern, but keep the developer moving slowly and continuously.

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Thank you!

I have lifted the edge 10mm or perhaps more.

I keep Orbital usually at shallow water bath. So shallow that Orbital tank does not float. So the gently lifting on corner is easy.
I have somehow developed kind a fear of too little agitation, which has driven me to agitate too much.

I did some testing with my orbital last week to see how much agitation was needed to cover the film adequately. If I use the base and rotate by hand there is a lot of movement round the edges with just a little across the inner sides using 300ml of fluid (tested with used film and the lights on). I experimented for a while and found that the gentle agitation discussed here worked very well with just a small amount of movement needed to cover all four sheets of 4x5 using 150ml of chemicals. The best method of all seemed to be 15 secs of Manual rotation followed by gentle side to side tilting.

In the past I'd simply used constant rotation which usually delivers well enough developed negs.

Steve