Mottling on Shanghai GP3 100 3x4 sheets

[Nas]

Has anyone had nice results from Shanghai GP3 100 sheet film? Here are some shots from last weekend which I developed in a Jobo expert drum with manual agitation on a roller base. I didn't use a water pre-rinse and I used water instead of stop bath. There is a visible mottling which is very obvious in the shadow areas and in the sky of the first image. Film is fresh from Nik & Trick a couple of weeks ago.

Previously I had used a water pre-rinse and stop bath which resulted in the same kind of mottling so I'm at a bit of a loss. Next I'll try a Paterson Orbital and see if the drum processing is the problem.

 

[Monsta]

Is this shot on a graflex as you can get tiny pinholes in the shutter cloth which can do this? With Shanghai if I use pyrocat I get a weird scum type on them but this doesn't look like that.

 

[David M]

If it’s pinholes, all the mottling will be in the same place.
I’d be inclined to try something even less exotic than Rodinal. D76 or ID11 suggest themselves.
Other thoughts… are you using a sufficient volume of developer? Are you using a long enough time? Most instruction sheets warn that short times will give uneven development. Have you changed your rotation speed?
I apologise for the next suggestion. Can your loading/unloading process be leaving something on the film surface?
A very long shot would be internal reflections in the camera.
If you develop a couple of sheets of entirely unexposed film and can detect mottling, this will suggest that it’s the film itself.

 

[Nas]

Thank you both for your suggestions. One thing I noticed with the sheets in the Jobo expert drum was they were too small to curve around the wall of the round tubes inside the drum so they weren't flush against the wall they were more like flat diagonally across the diameter. Not sure if that has caused or contributed to the mottling. I will try the paterson orbital and a different developer next. I don't think it's pinholes because the mottling is different in various shots and I used the same shutter speed for all 6 shots.

 

[Dave_P]

This could be something to do with storage or something like that - maybe some condensation has happened to the film (like if it's been taken in and out of refrigeration a few times). Or it's possible maybe at some point the one of the developer/stop/fix/wash has been at a dramatically different temperature to the previous bath. Other than that, these actually look very evenly developed (as you'd expect from the Expert drum), so I wouldn't expect dramatically changing the development method or times to fix this (unless it fixes it by chance as a secondary benefit). Also doesn't look like pinholes either.

 

[Nas]

This could be something to do with storage or something like that - maybe some condensation has happened to the film (like if it's been taken in and out of refrigeration a few times). Or it's possible maybe at some point the one of the developer/stop/fix/wash has been at a dramatically different temperature to the previous bath. Other than that, these actually look very evenly developed (as you'd expect from the Expert drum), so I wouldn't expect dramatically changing the development method or times to fix this (unless it fixes it by chance as a secondary benefit). Also doesn't look like pinholes either.

Thanks, Dave. Storage conditions are unknown before I received the film. I have kept them in a cool room since purchase. The sheets of film are interleaved with sheets of paper which is smooth but if you're right about condensation then maybe the mottling is due to paper fibres interacting with the film. I can rule out temperature variation during processing because I checked everything.

 

[LinhofM]

Has anyone had nice results from Shanghai GP3 100 sheet film? Here are some shots from last weekend which I developed in a Jobo expert drum with manual agitation on a roller base. I didn't use a water pre-rinse and I used water instead of stop bath. There is a visible mottling which is very obvious in the shadow areas and in the sky of the first image. Film is fresh from Nik & Trick a couple of weeks ago.

Previously I had used a water pre-rinse and stop bath which resulted in the same kind of mottling so I'm at a bit of a loss. Next I'll try a Paterson Orbital and see if the drum processing is the problem.

I imagine these are scans of the negative. But, in case they are scans of the prints, that effect is common, in my experience, when the paper is old or has been exposed to moisture.

 

[Nas]

I imagine these are scans of the negative. But, in case they are scans of the prints, that effect is common, in my experience, when the paper is old or has been exposed to moisture.

Yes, these are scans from the negatives. I've just posted my camera off for servicing due to a slightly lazy shutter but when I receive it back I will continue with testing.