"Stacked" semi-stand?

[jstraw]

I'm having very good luck with semi-stand and a staining developer.

I just acquired a Jobo kit that would allow me to process up to 12 sheets of 4x5 at a time, in two reels, stacked.

I'm concerned that the reel with 4x5 sheets on the bottom and the reel on the top will not get the same development during a stand, semi-stand or EMA method.

Thoughts?

 

[sanking]

I'm having very good luck with semi-stand and a staining developer.

I just acquired a Jobo kit that would allow me to process up to 12 sheets of 4x5 at a time, in two reels, stacked.

I'm concerned that the reel with 4x5 sheets on the bottom and the reel on the top will not get the same development during a stand, semi-stand or EMA method.

Thoughts?

When I do semi-stand I reverse the orientation of the tubes at the half-way point to compensate for the fact that the developer by-products fall to the bottom and in theory at least the solution at the bottom is weaker than at the top.

Sandy King

 

[phaedrus]

No problem here, I use the same Jobo Drum with 12 sheets and Prescysol semi-stand development. To avoid unevenness I fill the drum to capacity with 2500 ccm of developer.
Good thing Prescysol is diluted rather much!

 

[mikebarger]

Michael

I think your using 510 pyro, what film you using?

I'd be interested in development times for a starting point, I've been thinking about trying the semi stand.

Mike

 

[jstraw]

Mike, yes...FP4+ in 510 Pyro, 1:500, 50 minutes...30 seconds of initial, continuous agitation then three inversions at 12.5, 15 and 37.5 minutes. Oh, and 5 minute presoak with agitation every thirty seconds.

You can try one of my Combi Plans out if you like. I wouldn't enjoy semi-stand without daylight tanks.

I'm about to start shooting some night stuff with HP5+ and plan to use the same times as a starting point.

The trade off, using the Jobo would be 12 sheets in 50 minutes vs. six....but using 2500ml instead of 2000ml with the Combi Plan HP. At 1:500, that's 5ml of stock vs. 2ml.

I don't often have 12 to do at a time but when I do, I think it's a good trade off.

Sandy, I could do that with the Jobo if the lid doesn't leak. I'll fill it with water and find out.

phaedrus, good to know!

Thanks everyone.

 

[mikebarger]

I've got a couple antique Jobo tanks with, I think, 2021 reels that I can use for semi stand. I've been using them on a beseler roller base.

At one time Jay had given me starting times for semi stand with 400 tri-x in 120 and HP-5 in 4x5, but somewhere I've misplaced the notes.

Now I've started a notebook to keep data in.

Thanks

Mike

 

[jstraw]

The massive dev guide lists 7 minutes for FP4+ and 5.5 minutes for HP5+ in 1:100 for 35mm film. That translates to a very rough guideline that HP5+ requires 93% of the development that FP4+ does. 93% of 50 minutes is 46.5 minutes. I'll risk the slight overdevelopment and if 50 works for HP5+ I'll be able to process both films together.