View Full Version : Anyone Use Pyrocat-HD in a Paterson Orbital Processor?

6-Mar-2011, 21:29
I've got some Pyrocat-HD coming as well as a Paterson Orbital. Any recomentadions or tips for developing Ilford HP5 in it? I'm just getting back into LF and the darkroom so I'm a little rusty!

7-Mar-2011, 02:05
I use.
There's nothing special with Pyrocat-HD.

With motorized base the orbital seems occasionally give a bit more edge density (with all developers) but when agitating the orbital tank manually on the water bath, it gives really even development.

350-400ml of developer is good. With motorized base, much less is enough in theory (150ml or less) but I have found that the more developer, the better the result are.

Dilution 1+1+100 works fine.

7-Mar-2011, 02:10
Agree with Jukka, I used a friends Paterson Orbital last Autumn with Pyrocat HD, manual agitation, 300ml Pyrocat HD with results identical to my Jobo tanks (inversion agitation).

You'll need to look up how to modify for 5x4 film.


7-Mar-2011, 02:39
Never used the motorised version. I had a manual base and threw it away. I use maybe 300ml of fluid (although not Pyro, universal dev) and tilt it at intermittent intervals for the entirety of development time. The idea is it keeps the whole film covered but the agitation is inconsistent and not too violent. No problems so far

7-Mar-2011, 16:02
I've got the motorized base and the manual. So most recommend not using the motor? I might try intermittent agitation by allowing the motor to run and stopping it periodically during development. I would really like to use the motorized base if possible. Thanks

7-Mar-2011, 17:06
You can try the motor. I guess that the result depends on the film and developer.. And the motor base.
My orbital doesn't always do full circular movement during tilting but instead stucks and starts doing only tilting movement. Thus result isn't always even.

However I have got a lot of nice 4x5 negatives with Pyrocat-HD and motorized base. The films were Fuji Acros, Adox CHS 100 Art and Adox Pan 25.

Now I use the Orbital just like a daylight sloshers. I put a tank on the water bath (16x20" tray) with water just enough that the tray are on the limit of begin to float.
I agitate first seconds by rocking the tank randomly, then settle down to slower, circular rocking. Left side up and down (tooks about one second), back side up, right side up, front up, left up... Until first minute is full.

Then I do same pattern every minute, completing two rounds and changing the direction from clockwise to counterclockwise every time.

The big advantage over the motorized base is the water bath that allows longer developing times (it's never drop below 24-25 degree celsius in my house). The longer developing times means better change to get even result.
The downside ofcourse is manual work. The motor really makes thinks easy!

One reason why I like to use orbital tanks is that I can reuse tank (or tanks as I have two of them) immediately. The new negatives can be inserted even the tank is still wet.

With 8x10 that's big advantage. With 4x5 I do also tray development and some drum development.

For modifying to 4x5 and 5x7, I have following mainly modification of this site: http://www.rogerandfrances.com/subscription/ps%20how%20orbital.html

But as I don't have the original pegs and didn't found any tees many people use instead, I use plastic M3 screws.

8-Mar-2011, 07:06
I had trouble (http://www.largeformatphotography.info/forum/showthread.php?t=71624&highlight=cor) with even development of HP5+ 8*10 in a print drum, I switched to my Orbital, and have excellent results (http://www.largeformatphotography.info/forum/showpost.php?p=685811&postcount=14) (I did about 6 sheets more after that shown example).

I can use max 300ml 1:1:100 Pyrocat-HD, which is also the minimum volume stock needed.

I did not do anything to the bottom of the tank, the anti-halo layer fixes out nicely.

I use an older model lab shaker, comparable to this (http://www.analis.be/products/product.asp?idP=29&prodCatg=736&prod=3315)



8-Mar-2011, 15:41
Cor, so your using the paterson tray on the lab shaker? I might have to go that route if I cant get consistant results with the motorized base.

9-Mar-2011, 01:00
Cor, so your using the paterson tray on the lab shaker? I might have to go that route if I cant get consistant results with the motorized base.

Yes, indeed..but I guess it's kinda hard for most people to pick up or have access to such a device, but I doubt it is really necessary anyway, since most people get great results without such a shaker.

Good luck,