Allright, I put together a little test, based on the tips and ideas in this thread.
I just got my 100 ft Fomapan 100 bulk film loaded and ready and thought i's give it a go with a limited film-strip, to check the following:
- How various filters (the ones that I own anyway) influence the sky (with this film)
- Try HC-110 with Fomapan 100 (something that is "not recommended" for more reasons I care to remember)
- Try out n+2 development with said film, to see how it fared.
I metered, to the best of my ability, the darkest parts of the sky to zone III, the highlights were then at zone V (I used my Canon 1v's spot-meter) and took a photo without filter.
Metered again with a Hoya #25 red filter on and took another photo.
Then I mounted my Polarization filter on-top of my red filter, metered again and took another photo.
For development I googled around and found 8 minutes at EI 100 for foma in HC-110 dilution H to be a good starting point. (I've never used HC-110 with Fomapan 100 before).
I then added 25% to that time, to get to a theoretical n+1 development.
Then I added another 25% to that time to get to n+2 development. (12,5 minutes)
(This was a guestimate, I have no idea of it was correct, because I don't own a desiometer)
The reason why I shot this for a n+2 development, was that I wanted to keep the darkest parts of the sky and the clouds _dark_ and use the development process to pull up the highlights, as per the zone system (or the maybe the bit simplified one that I use).
I then developed the film for 12 minutes 30 seconds, 1 minute continuous agitation, then 1 gentle agitation at 3, 5, 7, 9 and 11 minutes (and a light "cheers" at 12 minutes), making sure to not agitate too hard or too much, but let the highlights get a batch of fresh developer now and then.
The result:
Filter effect:
Wow!
You can clearly see the difference between the unfiltered shot, to the #25 red filter shot, but look at the red + pola!
Ansel Adams go home, haha
Fomapan 100 in HC-110:
What's the problem? The negatives look good and if you keep you fat fingers (and fat squeegees) away from it while wet, there is no problem!
Now, this was a "sky-test" alone, I have yet to test to see how trees and water will fare when I use this technique, most likely I'll have to stash a square ND filter on somewhere, to prevent the land part of the image to go too dark on me.
N+2 development with Fomapan 100:
I guess I got lucky, the negatives look very nice to my eye, scans well, not too thick, not too thin, will print well in the darkroom.
N+2 was maybe a bit much though, because the negatives (at least from my grain enhancing Nikon-scanner) are a bit grainy in 35mm. I need to print some in the dark-room to get a proper impression.
Conclusion:
If I was to do it again, I would place the shadow part of the clouds at around zone IV, so that the whites were at VI (may vary depending on conditions off course) and then do a n+1 development instead. (it can go really stark, very fast).
Result scan of the negative frames side by side as they appear on the negative is attached (photo darkened to where I typically do it when I make a proof-sheet in the dark room), this is a proof scan, scanned trough my negative sleeve, so never-mind the dust specs, they are on the outside of the neg-sleeve. Also, the neg-leader shows some unevenness in brightness, probably due to said sleeve.
Also attached, a proper scan from the #25 filter + pola filter, made on my Nikon V.
I hope you enjoyed this totally unscientific test as much as I did ^^