So generally, I’ve always understood that the lowest ISO is best to shoot at. Though with newer cameras, they usually have a higher base ISO and in some cases Dual ISO.
I usually work with the R5C, even for photography. It feels odd to take portraits at 800 ISO because I’ve always been told it should be as low as possible.
So does the Base ISO system, negate the need to shoot at lowest ISO for the clearest and least grainy image?
So is it better to have iso at auto
If Auto will do it for you - sure. Remember that you’re not hurting anything by shooting at the ISO the shot needs, and on older, variant sensors you don’t hurt yourself in post by shooting at too low of an ISO, which can end up giving you even more noise when you correct those shots in post.
There are times when pushing in a bit of Exposure Compensation is needed, some amount of -Ev to defend against blowing out your highlights or the opposite, dealing with backlit scenes where you need more ISO and +Ev than auto wants to give you.