I want to convert my 4x5 P into a wide angle 8x10. Sinar retail prices remain otherworldly, so this is strictly a used equipment transaction.

I see some conversion kits claiming 'metering' backs and some stating 'non-metering'. Also, I see some bag bellows listed with each specifier. In particular, B&H says: "The 8x10 Tapered Bellows is available in two versions: for current meterback (MB) cameras and for the older, non metering frames (Non-MB)."

So you need a different bellows for an ONMB (Old Non-Metering Back) and a NMB (New Metering Back)? In which case I have to be dang sure that the back and bellows I buy correspond in terms of meteringness? Sheesh, I thought Sinar stuff was supposed to be self-compatible!

And I still don't understand what a 'frame' is...