On my A7s I noticed that when shooting in SLOG2 if I go up to ISO 8000 the image will have a different noise pattern than if I go up to ISO 10,000 and then down to ISO 8000, same ISO but totally different noise
I know that people have reported a similar issue with the A7sii with SLOG3 but what I read was it was believed to only be a bug with that picture profile
It's this kind of "Trick" ISO that does something weird to the noise
Going up give the ISO a kind of "Dirty" grain but going down to the very same ISO will give the ISO a "Clean" grain
I compared Native 3200 to this ISO 8000 when it had a "Clean" noise and also the "Dirty" noise http://imgur.com/RzOCZko http://imgur.com/AWU0IED http://imgur.com/G6QoXWl
The thing is I see this not just on SLOG2..I see it on all picture profiles..on multiple different camera models...
On the A7s this happens on the following Picture Profiles on the following ISOs: http://imgur.com/SLmoyEF
Here is a video of me going over the issue and explaining more in-depth: https://youtu.be/Omp5SMrifwI