Uneven Skies w Pyrocat and Foma in 8x10

[gbenaim]

Hi all,

I'm having trouble getting even skies using pyrocat-hd at 1:100, 3 liters per 11x14 tray, and foma film in 8x10, and am curious whether this is a problem of technique or materials. I should say that I'm tray processing and developing by inspection, and that my dev temperature at present is around 74-75 deg. Not every neg w skies shows unevenness, and negs without skies show none, at least that shows up on a print. The kind of unevenness is of 2 types. Either along the edge of the sky, when there's a small amount of sky at the top, and it looks like a sine wave (loosely speaking) alternating areas of lighter and darker sky. The other type is where in a large expanse of sky, there'll be blotches or spots in the middle.
So, would cooler developer make a difference, or is it a matter of especially finicky materials when it comes to sky tones? Any and all pointers are appreciated.

GB

 

[TheFlyingCamera]

That SOUNDS like an agitation problem, causing developer surge at the edges of your negatives. How are you agitating your film? are you shuffling your sheets in a stack, or are you putting it in the soup and then rocking the tray?

 

[gbenaim]

Scott, I shuffle constantly.

 

[wilsonneal]

Are you pre-soaking and for how long?

 

[TheFlyingCamera]

It could still be wave action rebounding from the edges of the tray - try going up to a 14x17 tray and see if that solves it. As to the mid-frame blotches, not quite sure what to try to eliminate them. I don't run into this problem anymore since I switched to rotary processing.

 

[T Hoskinson]

It could still be wave action rebounding from the edges of the tray - try going up to a 14x17 tray and see if that solves it. As to the mid-frame blotches, not quite sure what to try to eliminate them. I don't run into this problem anymore since I switched to rotary processing.

I don't have this problem processing in BTZS type tubes or when processing in a slosher tray. I use a tempered DIW pre-soak and I use very gentle agitation when developing.

 

[PHOTOTONE]

I have not procesed Foma films in Pyro, BUT I have extensively processed FOMA made films, primarily in HC-110, Dilution E. I have to say that FOMA is the most finicky as far as agitation goes, and if not agitated enough or frequently shows uneven development. I always use a water-bath presoak for several minutes with agitation. Have you tried a water pre-soak and then just processing one sheet at a time?

 

[domaz]

Does it only happen with higher shutter speeds? If so maybe it's the shutter, although that does seem kind of unlikely with a leaf shutter.