FP4; long exposure + extreme pull

Any tips for compensating development with FP4 used in long exposures? I am trying to get barely printable detail in window drapes that I exposed four stops above middle grey. This put the darker parts of the drapes at two stops above middle grey.

I chose FP4 because I love the way it handles highlights. Film was rated at 100. The meter was a Pentax Digital Spotmeter.

However, I have no real experience with this film in long exposures, so I am asking for you all's experience to help me out.

Bright part of curtain: EV 9 and one dot
Darker part of curtain: EV 7 and one dot

I made the exposure as if EV 5 and one dot was middle grey.

I want a silhouette of the edges of the grand piano, with the tiniest amount of low-toned sheen on the curves and on the wooden floor of the stage. No detail in the blacks is desired (though if a little ends up there, it is no big deal); just that slight sheen on around zone II-III.

My indicated exposure for f/22 was 8 seconds plus two dots.

I made exposures at:

f/22 at 1 minute, 4 seconds
f/22 at 32 seconds
f/22 at 16 seconds
f/22 at 8 seconds (just to see how bad I would end up if I used the indicated exposure)
f/16 at 8 seconds
f/16 at 16 seconds
f/32 at 32 seconds
f/32 at 1 minute, 4 seconds

I shot a lot, since I was unsure of myself regarding reciprocity failure. I shot at various apertures because I was interested in examining the D of F I get with this lens when shooting from far away. Normally, I am shooting up close with it.

Camera was a 4x5 with a 360mm lens on a DB shutter from about 35 feet away.

Thank you in advance!

P.S.

I have everything I need to make D-23, and that is what I was leaning toward doing...perhaps without so much sulfite, though. How will it affect ph/develoment if I half or quarter the amount of sulfite, or leave it out entirely (develop in just water and metol)? I have used a straight metol solution as bath A of a two-part developer, but never without part B (which was made up of water and an accelerator).

I was thinking of using it diluted as well. 1:3? 1:7? Any thoughts? Dilute developer effects would be OK by me for this shot. It would be neat to really "crisp up" the edges of the silhouette and the fibers of the drapes.

P.P.S. I don't have a gram scale at home. I normally use the one at school, but it is summer. I have plenty of kitchen scales. I got my stuff from Formulary.

I cannot give you all answers, but I can reasonably say that if your metered exposure was 8 seconds, then 30 seconds of exposure is about correct, or in my experience, will give you the best chance of obtaining a good neg.

Last year I switched to FP4+ in 4x5" as my TMax100 was finally running out.

I did some testing and part of that was a local town hall which is a light cream painted stone. As evening approached my meter told me f/22 at 8 seconds at 100 ASA, which is what I rate FP4+ at.

Using D76 neat, I had my best negative from the one exposed for 30 seconds. I was able to get a reasonably good range of tones.

Although shadow detail was a bit lost, highlight detail was just printable, I was able to retain detail just before the pure whites go dirty under the enlarger, if you know what I mean. A poofteenth more exposure and the print was as muddy as anything. I would suggest you may care to think of split tone printing for this subject, I think I would.

A question regarding your light meter readings; EV 7 plus one dot, is that the same as EV 7 plus 1/3 of a stop?

Or in another system EV 7 plus 1 DIN?

Mick.

Well there is always POTA All the detail will be there but you'll get a pretty flat neg, so then you just diddle with the contrast grade to get what you want. When you say "tiniest amount of low-toned sheen" that strikes me a very fine adjustment perhaps better made at the print stage anyway.