X-Ray Film and Paterson Orbital Tanks

[Leigh]

Processing time is a function of emulsion thickness, among other things.

X-ray film has very thin emulsion, so processing can be done quite rapidly.

It also has emulsion on both sides, to double the contrast.

- Leigh

[Jody_S]

Hi Jody_S,
Isn't it incredible that X-ray film can be fixed and washed in this short period of time!
I noticed that fixing seems to be complete in less than a minute, how long do you wash for?

Mark

10-15 mins in running tap water, no issues with 200 or so sheets. I wash again after stripping the reverse side.

[C_Remington]

If orbital works normal film, why did u ever think it wouldn't work for X-ray?

[Geraldine Powell]

I use 120 ml of developer in my orbital processor, (Xytol for the most recent batch). I have never had any banding. I do continuous manual rotation.
I put little plastic game counters on the bottom of the tank with superglue to prevent sticking of the negatives.
Geraldine

[Mkillmer]

If orbital works normal film, why did u ever think it wouldn't work for X-ray?

X-ray film is double sided and has a very fragile coating when wet.
The problem isn't developing the film, its preventing scratches.

[jcoldslabs]

Processing time is a function of emulsion thickness, among other things.

X-ray film has very thin emulsion, so processing can be done quite rapidly.

I've been testing some very thin emulsion aerial duplicating film and have been getting good results with rotary processing for 2 1/2 minutes using HC-110 1:39. As Leigh says, not all films need 5+ minutes to fully develop.

Jonathan

[Ed Bray]

Very interesting! What developer/concentration are you using?

I use Caffenol C-L (1.4g of KBr) @21 degrees C with 4x 4x5 or 2x 5x7 films in a Paterson Orbital Tank with constant gentle agitation for the 1st 30 seconds and 3 gentle agitations of the tank after the following 2, 4, 8, 16 minutes with the Caffenol drained out after a further 39.5 minutes (total 70 minutes).

Caffenol is really easy to make up and the hardest part for most people is finding the Sodium Carbonate (anhydrous).


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[Andrew O'Neill]

Sodium Carbonate

One should easily find it in a supermarket. I have a big box of Arm and Hammer Washing Soda.

[Corran]

It also has emulsion on both sides, to double the contrast.

I think this has been stated before but also refuted. I don't think the double-sided film has "double the contrast," just double the density. I've never noticed a difference in contrast characteristics from film that I bleached one side of, or those that I did not.

Also, I routinely develop 8x10 sheets in a BTZS tube with only 2.5mL of Rodinal (1:100 dilution) with no problems, constant agitation.

[Ed Bray]

One should easily find it in a supermarket. I have a big box of Arm and Hammer Washing Soda.

I'm pretty sure that the Arm & Hammer is not Anhydrous and you either need to bake it (to reduce the moisture content) or use a lot more to give the correct amount of Sodium Carbonate for the formula (with a slight decrease in the amount of water used).