Are there any very slow (ISO 6 or 12.5) medium format films availiable?

[sepiareverb]

Stacking filters tends to cause vignetting with some lenses. I often shoot in situations where a 400 speed film is too fast for the available shutter speeds on my camera. But I will not convince anyone that there is a reason to want to pull films as I'm clearly wrong. Lets figure out how to make the OP change his question so we can talk about something else.

 

[EdSawyer]

Tech Pan was available in 120 and is still available on ebay and elsewhere. Normal rating of 25, and with age shooting it at 12 might be about right.

 

[pentaxuser]

Sorry I was referring to paper negatives.

No "sorry" required. It was my fault in fact for making a false connection between a previous post (#11 ) which referred to Pan F in another context and then your post 12 which was in response to another post. It would have become quite clear if I had taken the time to read the quote in your post to which you were replying.

pentaxuser

 

[iandvaag]

Since you mentioned fine-grain, this suggestion is probably not what you're after, but it bears mentioning that Rollei IR 400/Superpan 200/Retro 400s are exposed at an EI of about 3 to 12 when shot through Hoya R72 filter or equivalent (IR pass 720 nm.) Available in medium format.

 

[NB23]

Since you mentioned fine-grain, this suggestion is probably not what you're after, but it bears mentioning that Rollei IR 400/Superpan 200/Retro 400s are exposed at an EI of about 3 to 12 when shot through Hoya R72 filter or equivalent (IR pass 720 nm.) Available in medium format.

Fomapan 400 as well. Beautiful results.