Lss
Well-known
There is nothing bad about auto ISO as a feature, it's a useful tool for many photographers. The Leica implementation is actually very good by providing the essentials: you can limit both ISO and shutter speed. This is not a given with even all much more modern cameras. Whether you want to use auto ISO all the time, sometimes, or never is a completely different thing and depends on your needs and preferences.Is auto ISO that bad? I set it to tap out at 640 as I read beyond that gets a bit sketchy.
My default for auto ISO on the M8 is 1250. For me, the whole point with auto ISO is added flexibility when light levels rapidly change back and forth. Limiting auto ISO to 640 takes away one stop of flexibility without much visible gain. Going up to 2500 gives another stop, but the toll on image quality is already considerable. When I simply want automatic exposure, I will rather use AE with fixed ISO. And when I don't want that either, I use manual with fixed ISO.
While the M8 gives you auto ISO also when you set the shutter speed manually, it does not really allow a huge range of flexibility. This is one thing where the M8 not being an ISO monster shows. It is however convenient to jump between AE and manual when using auto ISO. This gives you an additional shutter speed limit setting in auto ISO (the first one is the AE one buried in the menu). Of course, this means you actually need to consider the light levels and exposure without blindly following the meter (and possibly histogram), but that is basic photography anyway. It's a good tool.