Paterson Orbital question

[Keith tapscott.]

I am looking to buy a Paterson Orbital soon and was wondering how you agitate the films to ensure even development. Advice on developer volume etc would be appreciated.

 

[mpirie]

In my world, i have the Orbital sitting in a tray of water at 20 deg. The tray is filled with enough water to allow the Orbital to float and to make the rocking easier.

Agitation was rocking for 30 sec left to right, then 30 sec top to bottom.

I would do four 5x4's or two 5x7's at a time, normally with 500ml of developer to make sure exhaustion wasn't a problem. I'd also pre-wash with 500ml of water.

I glued some plastic washers onto the red pegs that are used to stop the sheets coming in contact with each other and floating up into other sections.

Mike

 

[David M]

That sounds about right. Many people roughen the base, either by scoring it, placing little blobs of epoxy, or sticking little plastic buffers on it. Without this, the film may stick to the base and prevent the backing coat from clearing. The motor base, if you have one, is too vigorous for film and may over-develop the corners

 

[Alan Clark]

Developer volume - When I used my orbital with grooves scored in the bottom with a knife point, 300mls was enough to cover the film sheets. I got occasional sticking so eventually put blobs of glue on the bottom for the film to sit on. This raised the sheets up by a couple of mm. so I had to increase developer volume to 600 ml to cover them. The film was now in danger of touching the fins, so I removed them.
Agitation - Continuous and very gentle, and totally random. My orbital sits on the kitchen work top. I agitate by lifting a corner - or a side- no more than about 5mm. Then another corner, and so on. I don't stop. When I tried agitating every 30 seconds as you would a paterson tank, I got very uneven development.

Film is placed in the tray emulsion side up; an obvious point but worth mentioning.
If you put blobs of glue on the bottom, UHU all purpose adhesive is excellent. (yellow tube, available from stationers)
If you have some spare film it is worth putting some in the prepared orbital, then putting water in to see how much you need to cover the sheets of film at their outer (upper) edges.

 

[mpirie]

Yes, i should have mentioned i roughened the interior base and applied 5 rubber bumpstops per 5x4 section, so 20 in total. The self adhesive things that stop kitchen doors banging shut.

I also removed the fins in case the film floated and touched them.

Mike

 

[Keith tapscott.]

Thanks for the advice, much appreciated.

 

[David M]

An occasional problem with generous amounts of liquid is that the negatives may float over the top of the standard red pegs and overlap each other. Making longer pegs will cure this.
Because of the floating problem, some people do remove those fins. This seems to have no adverse effects. Presumably they seemed a good idea at the time.

 

[AnalogueWendy]

I’ve had the floating and overlapping problem. Mine also now has blobs of 2 part epoxy in the base to avoid sticking.
I find 350ml of dev solutions is enough. Any more than that sloshes out or at the corners.
Important note, 4x5 is the smallest film size. Quarter plate is too small and tends to wriggle
its way between the pegs, leading to more overlapping problems.

 

[Tony Miller]

I also used drawer bumpstops glued to the bottom but use plastic machine screws in the holes instead of pegs. Two longer in the middle and two shorter on the outside. This is my 5x7 setup. 350ml liquid with constant agitation on the rocking base (not motorised).

 

[Keith tapscott.]

I also used drawer bumpstops glued to the bottom but use plastic machine screws in the holes instead of pegs. Two longer in the middle and two shorter on the outside. This is my 5x7 setup. 350ml liquid with constant agitation on the rocking base (not motorised).

Hello Tony,

I like your Orbital design. Silly question, where can I buy the drawer bumpstops and plastic screws?

Thank you everyone for replying.

 

[David M]

B+Q.

 

[Tony Miller]

I can't take credit for it Keith. Trevor Crone has the definitive article (with lots of useful contributions) over at FADU. I think if you read through that article, and comments. all your questions will be answered.

Developing Sheet Film in a Paterson Orbital Processor - Film and Darkroom User

Developing Sheet Film in a Paterson Orbital Processor Articles

www.film-and-darkroom-user.org.uk

 

[Keith tapscott.]

I can't take credit for it Keith. Trevor Crone has the definitive article (with lots of useful contributions) over at FADU. I think if you read through that article, and comments. all your questions will be answered.

Developing Sheet Film in a Paterson Orbital Processor - Film and Darkroom User

Developing Sheet Film in a Paterson Orbital Processor Articles

www.film-and-darkroom-user.org.uk

Thank you Tony. I will have a look over on FADU.

 

[Pete Spencer]

I have used my orbital with manual agitation and without modification to process Foma 100 ASA 5x4 fil without problems. I've used a 10 second rocking motion agitation per one minute of development, The green anti-halation ldissolves off perfectly.

I have some 5x7 to process and don't know how that will turn out.