The Waterpoint

Yes they are, low res JPEG export causes them.

Agreed. The sky itself isn't too bad until it gets near other stuff ...

zoomed a lot then exaggerated in Levels:

Those artefacts might also be partially caused by any post processing (darkening highlights for example) either in camera or in post.

The exif data shows you used spot metering which is not the mode I would normally use for a scene like this.

If you spot metered anything that was less than 18% grey, it is then highly likely the sky would be much lighter than what you saw and so would need dialling back if not clipped.

Do you recall why you used spot metering and what you spot metered on?

Also, do you recall why you set ISO 320?

I would think you could have easily set base ISO which would have let more light onto the sensor and so reduced any visible noise in the shadows.

Thanks for the advice. The camera was set to f/8, 1/500, with spot metering for street shots. I didn’t pay any attention to ISO at the time. I usually use center-weighted metering, but it was on spot metering, likely because of the previous shot. In general, I don’t think an ISO of 320 is particularly troublesome. The scene had a high dynamic range, so either the shadows needed to be lifted or the highlights reduced. I think the exposure was OK, but my processing to match the OP’s colours introduced some extra noise and some artefacts. Particularly poorly made masking did (AI did it and I did not refine it).

It sounds like iso was set to Auto which is what I usually set it to when hand holding.

The point I was making is that, assuming 1/500s wasn't a minimum you required for some reason, a slower shutter speed would have allowed more light onto the sensor with the benefit of less visible noise in shadows.

In any case, the scene had good light so it's not a big deal. It's in low light situations where maximising the amount of light onto the sensor without clipping highlights has more noticeable benefit.

I was just curious about what you spot metered in the scene and why iso was 320.

That's right, I could have turned the dial to reduce SS and get lower ISO but I did not pay attention. By the way, I keep ISO usually AUTO and use exposure compensation to play with ISO if needed.
I metered the upper part of the building. When I metered the sky it was very dark moved the spot a bot lower.

That's fine 😊

That's the way spot metering and the other metering modes work.

The meter will set the parameters it has control over for the shot so that the camera outputs an average 18% grey for the area being metered.

So if you spot meter something like the sky which is much lighter than 18% grey, the camera will try to make the sky 18% grey. Consequently everything darker than the sky will be even darker.

Fwiw, I find evaluative/matrix metering works best for me in most situations.

Thanks. That is what I originally suspected.

FWIW, a deep blue sky is 18% gray, thereby making an exposure correct and a light blue sky is only 1 EV more:

mastinlabs.com/blogs/photoism/understanding-middle-gray-and-how-to-find-it-anywhere?srsltid=AfmBOoqtplVN9xeuqNPj2Lm_zzh2g0_3FTUwd_yuXIiXXafJ4Sf_NN0N

On the other hand, I prefer full control over my exposure with all-manual control and spot metering. 😇

That's fine.

I normally use manual mode with base iso when using a tripod (with no movement in the scene) and when pointing and shooting (BIF, chasing grandkids etc etc) I normally use aperture priority, a minimum shutter speed set and auto iso. In both situations I normally use evaluative/matrix metering.

Centering/zeroing the meter needle is not normally a concern for me. What is more important is getting as much light onto the sensor within my dof and blur constraints without clipping important highlights. I go by the camera's histogram regarding how much light I can put on the sensor rather than centering the meter needle. The needle can land on +1 EV, 2EV, whatever, It doesn't matter as long as important highlights are not clipped.

If someone needs nice looking sooc jpegs then they will need to center the meter needle. If shooting raw you can largely ignore the meter needle as described above.

That's a generalisation and does not necessarily apply equally around the world.

In any case, your 1 EV difference is a 1 stop difference in the amount of light that can strike the sensor. That 1 stop can make a significant difference in the amount of visible noise in shadows.

Good.

Yikes, I would never have known ..

So "blue" sky is not necessarily a reliable 18% grey.

No problem.

Are we point-scoring today, Danno? I said "deep blue" not just "blue" ... of course, mis-quoting is a common way to score a point or two.

I'm out, I leave the coveted Last Word to you.

The point I was making is that even according to that chart there is a difference of 1 stop of exposure depending on how "blue" the sky is and so a "blue" sky is not a reliable 18% grey.

The lightness of a "blue" sky can vary significantly across a scene, especially when the sun is not far above the horizon.