New to large format - patterson orbital

[bill spears]

Hi everyone,
just wondering if any of you out there who are processing your 5x4 negs in the Patterson orbital and what suggestions you've got concerning modifications to the bottom of the tray to prevent the film sticking ??

I know there are several options ie: scoring with a dremmel tool, blobs of silicone, strips of film glued to the bottom etc.
I guess like most things its a case of trial and error but would be good to hear your opinions before I start attacking mine.

Also any problems with ueven development/streaking due to the solutions swirling around the separator pegs ?? I did get some problems with this on my first few batches and believed it could be from the fins underneath the lid. I've now filed these off but have yet to test it.

I've been processing rollfilm for many years but this is my first step with large format and its proving a difficult beast to tame !!

Cheers
Bill

 

[Steve Smith]

I scored mine with a Stanley knife. You just need something to overcome the films desire to stick to a smooth surface.

I have not seen the streaking problems you mention. Are you using the motor base? I use mine by hand and agitate for about ten seconds every minute as I would for a film tank. I suppose it's possible for the pins to cause a problem with continuous agitation though.

It is easy to think that the recommended amount of developer is not enough. Try it with water, some scrap film and with the lid off and you will see that it works fine. Most people still use a bit extra though.


Steve.

 

[Dave Miller]

I put a small blobs of slow curing epoxy resin adhesive at about 2 to 3 cm intervals all over the base. As it cured it settles down to a smooth shape that will not damage film. They have been subject to various developers and toners over the last six years and show no sign of deterioration. I have come to the conclusion that the use of the motor base is undesirable since I have occasionally noticed drag marks around the pegs with high key subjects, so I then used them on the manual base so that chemical motion is irregular. The recommended level of solution is fine, if in doubt do as Steve suggests and watch it in action with the top off. I have never had any problem with the fins, except when developing paper after failing to wash the top, I think the cause was residual fixer killing the developer locally.

 

[Dave Miller]

I should add that I reduced development time by about 10% to account for the continuous agitation.

 

[Roger Hicks]

I've never had a problem with 4x5 inch, but I have with 8x10. I believe that a roughened bottom allows 4x5 film to skate about enough to avoid problems. I used a Dremel on mine, 'kissing' the bottom with a little round grinder/graver.

 

[bill spears]

Had an idea that I might use some of those small domed plastic screw head caps and silicone them onto the base. They're very smooth and sit quite pretty on the bottom of the tray. Bit concerned about using scoring methods cos of abrasion ? I don't use the motor base either, preferring to keep the agitation irregular. I did find that I needed 350ml+ of solution to completely cover the sheets, any less and the outside edges weren't covered because the centre of the tray is deeper.
Thanks for the comments

 

[Roger Hicks]

The design of the Paterson tray assumes constant agitation, and there's little sense in doing much else with LF, so 100-150 ml is fine: the film is not uncovered long enough to cause problems. Silicone dabs alone will be at least as good as screw-head caps, and probably better, as there is no space under the silicone dabs to trap chemistry. Forget elegance: all you need is that the film doesn't stick.

 

[Dave Miller]

Whilst the primary purpose of allowing chemical under the film is to prevent sticking, and a build-up of chemical. I found that it also allows complete washing of both sides of the film, I used about 10 changes of water. You are using way too much liquid in my opinion, the plastic beakers supplied with the tray hold sufficient provided the tray is constantly agitated, even if you use Rodinal at 1:50. Much more than 100ml risks spillage, and is wasteful.

 

[Dave Miller]

Bill, You say you are not using the motor base, so I assume you are using the manual base, this will ensure that the small amount of chemical recommended reaches all the corners although you may have brought on coverage problems by trimming off the two "fins" which seem to divert liquid across the middle of the film area. The use of these trays has been discussed 3 or 4 times on this forum, so it is worth doing a search to find earlier threads.

 

[bill spears]

Whilst the primary purpose of allowing chemical under the film is to prevent sticking, and a build-up of chemical. I found that it also allows complete washing of both sides of the film, I used about 10 changes of water. You are using way too much liquid in my opinion, the plastic beakers supplied with the tray hold sufficient provided the tray is constantly agitated, even if you use Rodinal at 1:50. Much more than 100ml risks spillage, and is wasteful.

Yes am gonna try a much reduced amount of liquid next time. I didnt use any of the bases for agitation, just irregular rocking of the tray and turning it around for about 10 secs every 30sec. I can see I'll need to use constant agitation with less solution.

Regarding removal of the fins, Ithink I read it on another forum somewhere. Ah well, suck it and see !

 

[amuderick]

I scored the base with a Dremel grinder and then noticed some scratches on the non-emulsion side of my negatives. I went back in and vigorously applied some Novus #2 plastic polish with a cloth to smooth things out. Scratch problem solved.

 

[tim_walls]

Yes am gonna try a much reduced amount of liquid next time. I didnt use any of the bases for agitation, just irregular rocking of the tray and turning it around for about 10 secs every 30sec. I can see I'll need to use constant agitation with less solution.

Regarding removal of the fins, Ithink I read it on another forum somewhere. Ah well, suck it and see !

I've never used the Orbital for processing sheet film, but I have used it for processing prints (B&W before I got my 'darkroom'/trays sorted, and still using it for Ilfochrome) - I'd say you definitely need to use one of the bases for agitating properly. I can't imagine just rocking/turning is going to give you even coverage right up to the corners.

If you put 300ml in the tray while it's on the motor base, you'll end up with half the developer on the floor as it comes out of the sides. 100ml is plenty - so getting one of the proper bases will probably save you money too


Oh yes, only problem I've had with the fins is the same as someone else mentioned - make sure you wash and dry them well, otherwise they'll drip fixer onto the film/print during development...

 

[P C Headland]

I recently obtained on of these, and am very happy with the results.

I use the non-motorised base, and use 100ml to 150 ml chemicals to develop up to four sheets. I rotate it continuously, reversing direction every 20-30 seconds, and each rotation taking a little less than 2 seconds. I use my standard times less 10% (for Rodinal 1+50 and PC-TEA 1+50).

I stuck some insulating tape to the base of mine, with a thin wire underneath to create a bit of a ridge. I thought this would be a good way to start the modifications, since it is not permanent. Seems to be holding up well so far.

The above image shows the tape in two corners with the other two corners having a sheet of film in.

 

[bill spears]

Thanks for that. Its good to know all the possibilities. The tape and wire is one I would'nt have thought of, although I might be a liitle concerned about things coming unstuck and inflicting damage on the film. Definately an idea to work on though.
I eventually decided on a variation of the dremmel technique. A series of very shallow countersunk indents have been put into the tray with a drill bit. I finished off by smoothing it all down with very fine wet and dry and cutting paste to give a really smooth but dimpled bottom.

Gonna put it to the test right now !!