thanks :)

With normal usage, I get around 5-6 hours of SOT. I have the device for a year now. And I don't have many additional apps installed. Only the basic ones. I generally put apps to sleep when not in use to get more battery.

Maybe this is due to Scene Optimizer settings in camera app. Try disabling it and compare the results.

for front camera, use wide angle mode to get 8 MP images.

I've done factory reset after the pie update. I'm getting close to 6 hours of SOT. And not noticed any lag. But yes night camera was better with Oreo. Maybe Samsung can fix it with future updates.