Dan, the opening statement from Daran "taking an equivalent photo on a smaller sensor also requires using a lower ISO" is 100% correct.
No, it is not 100% correct. The equivalence adherents conveniently neglect the fact that different generations of sensors have different noise characteristics. Taken an extreme example, if you take the first picture on a circa-2000 FF sensor, then the second "equivalent" photo on a current generation APS-C sensor, the latter may (and likely will) have better noise performance at the same ISO.
Of course, the equivalence crowd will immediately refute: "we are talking about physics, light incidence", etc. and not the sensor characteristics per se. But in their other arguments, they often use the "end results" of printed images as a benchmark to support their point. You can't have it both ways.
My point is, if your primary concern is photography, and not some theoretical pedantry, "Equivalence" is not the be-all-and-end-all standard of final judgement. I still don't call it false and I think it has some merits, but when people get zealot and snobbish about it, it more often than not does harm than good.
Howard
Sep 21, 2026 at 08:43 PM
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