GR Digital V has an APS-C sensor

Exactly. A GR-D needs to be smaller than the GXR + Axx module. They should make it APS-C because the low-ISO is better than any smaller sensor, regardless of lens speed. To be specific - Dynamic Range, Tonal Range and Color Sensitivity are all better on APS-C and cannot be compensated by faster lens for a smaller sensor.

Ricoh shouldn't try to make the lens really fast if the size is to remain small. If the modest zoom I suggested (less than x2 multiplier) needs to be f/4.0-5.6 to be really small instead of f/2.8-4.0, so be it. Low light performance will still be as good as any combination that uses a smaller sensor and a similarly sized lens, so there's no loss, except maybe for those fixated on numbers rather than actual utility.

Prog.

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