imagemeister wrote:
This is the kind of subject you should be testing/comparing with ! -
https://www.uglyhedgehog.com/t-749907-1.htmlWhen you make your comparisons, ISO will be a major component ........the f4 possibility with the RX against an f8 possibility with the 6500/500 Reflex means the RX should be at 2 ISO stops lower in your test .
I am only commenting on your assertion that the RX10's IQ is better than some other, named cameras including the one I offered above. It's a very good camera I would recommend enthusiastically if it met the user's needs.
The RX10 in my experience (fully extended) is very good at F4 and best at 5.6 or F8.0 but the difference is slight. Remember, I used both cameras on "Auto". One could spend many more hours doing comparison testing. The 500 mm reflex lens is a prime and fixed at F8.0, nominally (closer to F7 in reality). It also has lousy DOF compared to a refractive lens.
Your comment on testing precision is probably accurate. But, more testing and more exacting setting-equalizers won't change the fact that the photo sites on the 𝜶6500 are almost twice as big as on the RX10 and a 500 mm prime lens is very hard to beat with a 220 mm 30x zoom lens. Btw, I verified that the 500 reflex that I have is very close in sharpness to the Tamron 150-500 so it is unlikely that any 220 can be twice as sharp, let alone at under $2k including the camera.
The area of the 𝜶6500 sensor is more than 3x that of the RX10 but the number of pixels is only 1.18x. The size of the pixel sites (assuming equal number per pixel) is thus 2.6x.
For an equal size target at an equal distance, a print with the same resolution will be 1.4x (lenses: 500 mm vs 220 mm). In reverse, the RX10 would have to enlarge 40% more and that's a loss of noise and/or resolution. It has to be 40% better IQ just to be equal on an equal print.
I know you like to shoot JPG-only and are a fan of Clear Image Zoom. In my extensive testing using CLI I was rarely if ever able to get better results than making the same enlargement in post-processing. In order to go beyond 220 (actual)/600 (equivalent) it's necessary to use one or the other or both. Within its optical limits the RX10 is a great camera and I use mine a lot, get lots of keepers, etc. It's also ergonomically the best camera I've ever used, bar none. Beyond its limits, other cameras including the alpha ILCE series will offer noticeably better IQ if used well and with good glass.
In addition, although not for everybody, the raw sensor on the 𝜶6500 has been measured better. See
https://www.photonstophotos.net and any other site on the 'net. Since I shoot raw almost exclusively that is an important factor. For the OP, maybe JPG is more important. Ulimtately, the JPG produced by the camera is only as good as the underlying raw from the sensor.