Not a lot of difference between the R3 and R4 besides the added MP and the resulting detail. An ISO range of a camera doesn't show how noisy its sensor is. There is a big difference in the last 6 years from the R1 to the R4. Sony increased the resolution while simultaneously decreasing the noise at high ISO. This was once thought of as a trade off. I want that new tech in the APS-C sensor.
I always shoot in raw but looking at the a6000 menu there is an option when shooting JPEGs to do
Hope soon to move over to Sony from Canon at the moment I use CF cards along side SD cards in the 7D MK II but what would/do you use in your Sony A9? Obviously you need a big card to take what I assume would be a lot more images at 20 FPS RAW (if you hold the shutter down) I don't go over 64GB on a card as I would rather change that card for a new just in case anything larger has a problem and you loose everything (never had a card fail but you never no) I also take it that you would need the UH
ISO-range of A7Riii and A7Riv are the same (100 - 32000), as is the dynamic range:
Even though I like the absolute sharpness and detail when I pixel-peep my photo's, it hardly serves a practical purpose. It's like the whole 4k - 6k - 8k discussion in video-world. Yes you'll see the difference if you're sitting at half a meter from your 65" TV, but who does that except the guy who just bought a new TV?