Ascenta wrote in post #18418457
This is even worse than PC vs Mac or iPhone vs Android.
I think it just comes down to trying both and going with what you like. After 10 years with an APS-C I finally went FF. Not going back. I'm totally thrilled with the quality and just the overall feel...something numbers, math and youtube videos can't do.
If it can't be backed up by (properly applied) numbers, it may very well be illusion.
There is no question that generally speaking, FF is a better choice for wide angles and shallower DOF, with similar overall sensor technology. Big pixels also absorb more light below f/2.8, the difference increasing the lower the f-number.
However, if someone hears that FF gives sharper results and less noise at the same ISO, and sells their 7D2 to buy a 5D2, and shoots the same things with the same lens from the same distance and crops the 5D2 more than the 7D2, they might actually see more sharpness and less noise at 100% on the monitor, but the thing shot will be smaller on the monitor. Jump to the future, and this person is displaying their work on a 16k monitor. The audience says, make that bird bigger, I can barely see it, and reluctantly, that person cranks up the magnification to 400%, and the bird is more clearly pixelated like a mosaic, with more noise, than if they had shot it with the 7D2 and cranked it up to ~250% for the same bird size on the monitor.
Also, if one is shooting macro and needs significant DOF, the bigger sensor does nothing for your noise; the FF advantage disappears unless you allow arbitrary exposure time at base ISO for a still subject.
To gather more light in a given exposure time and FOV, the FF sensor needs shallower DOF (which requires a larger, longer lens with a larger aperture, or getting closer to the subject with the same lens); it is not "another" option.