A9III’s Image Quality Is Not That Bad?

The weird thing is that no one that I deemed qualified (like Jim Kasson or Bcliff from Photonstophoto etc.) is testing A9III’s image quality so that I can just copy paste their results. So I guess lazy boy has to move his ass for once now.

I did a very simple test (since I obviously don’t have the camera, my capability is quite limited anyway) just to check the quantum efficiency of this camera:

1: Steal some RAW files from DPReview

2: Check the noise level.

If you just do some eyeballing, it looks like A9III is slightly noisier than A9II (this is also DPR’s conclusion).

But the numbers suggest otherwise. I picked 3 patches from the ISO6400 RAW files:

And here is what Rawdigger tells me:

Looks quite comparable. A9III is even slightly better in patch 1 (the brightest patch). However A9II does show some minor advantages in the darker patch which seems to implicate better read noise.

All in all it’s quite negligible. The low light performance looks OK to me. Dynamic range is another story for sure, given that the base ISO is 250. However, since this is a super fast global-shutter sensor, there is a ton of tricks that can be applied here to increase the dynamic range, as long as Sony wants it. In theory it can do bracket exposure faster than any consumer camera ever built. It’s pretty much the king of image stacking or computational photography.

(In reality though, Sony RX100VII, a camera also with super fast readout speed, only does bracket exposure at 10FPS, totally wasting the sensor’s potential, so I have to emphasize the part “as long as Sony wants it”.)

In the old days there is no cheat code for the low-light performance so it’s always more important than dynamic range. Nowadays Adobe’s AI denoise is doing some unrealistic stuff. Call me impressed and it kinda changes my way of shooting (I kinda don’t give a shit about ISO anymore…). Anyways I still believe that low-light is the core spec here so nice to see that A9III is not really falling behind. Also, for the target audiences (sport guys?) I guess they’re always shooting at high ISO anyways, so the ISO250 situation doesn’t hurt that much.