Ektachrome Dupe Film & Pinhole

I have a full box of Kodak Ektachrome Duplicating Film #6121 with nowhere to go. Not going to be doing any interneg work now or in the foreseen future. So I thought this film and my 4x5 Pinhole might make a good combo.

I was thinking of starting at EI-8 and developing in standard E-6 chemistry. Is there anything else I should be considering before leaping totally unprepared into this little project? Are there any filters I should look for to help with any color balance in the daytime?

Thanks...

Good Evening, Pioneer,

My recollection is that each box of 6121 comes with filter recommendations specific to a particular production batch. That might not be of much use with long-outdated film and would apply only to tungsten lighting. For daylight, most any filter designed for tungsten film used in daylight (85 series??) could be OK, since color rendition should probably be regarded as experimental/artistic in nature anyway. My memory tells me that 6121 does not age well, even when frozen. I think your idea of starting at about EI 8 is sound. Even lower may be better.
My own use of 6121 was primarily for long-exposure night shots where the low-contrast film characteristics were useful. I think that my first exposure (late dusk) was typically 4-5 seconds at around ƒ11-16; the second exposure, after artificial lights had all come on --maybe a half-hour after sunset, was typically 4-6 minutes at the same aperture. The usual subjects were cityscapes/streetscapes. Pinhole night exposures would surely be in fractional hours or beyond. I'd suggest starting at no less than 15-30 minutes for tests. The biggest requirements are a sturdy tripod and a high tolerance for boredom.
Konical

Great ideas I haven't opened the box yet so there may be an information sheet inside. I'll figured an 85B filter would be an option but thought I would start without any filters to see how it plays out.

Expect highlight crossover and anemic color saturation; and that's a best case scenario. Can't help you with the color balance because it has likely shifted too, and will need testing. But since this is for a fun what-if application, your guess of an 85B is a good starting point.