(07-23-2019, 01:15 PM)Brightcolours Wrote:(07-22-2019, 11:44 PM)Klaus Wrote:(07-21-2019, 08:47 AM)Brightcolours Wrote: It used to be that Sony stops down for AF a few stops with big aperture lenses with mirrorless and the live view DSLTs., even if you shoot wide open and even if your shoot in the dark. Since I have no Sony mirrorless camera I can not check into if they still do that.
As far as I understand, Sony does not focus a f1.4 lens wide open, but "relatively" wide open with Live View Display Setting Effect OFF, so not really wide open, the same as it was in the DSLT days? And not Af really at f1.4 but that rather illustrious "relatively wide open" when shooting at f1.4 with Live View Display Setting Effect OFF. So, when shooting at f1.4, but the lens not being at f1.4 during Af, you can see the reverse issue with a lens with real RSA issues that you'd see with the Canon EF 50mm f1.2 L USM in limited circumstances.
You can clearly see that the DoF changes in the viewfinder when stopping down.
In the bokeh highlight test the discs are at maximum size at f/1.4.
However, I haven't checked all this systematically. So far I haven't seen any negatives as far as Sony's AF accuracy is concerned - thus if the results are good enough, it's good enough for me.
The RSAs may be more relevant for macro but that's out of scope for the Sony 85mm GM. The min focus distance is pretty long.
Can you see the aperture closing a bit when focussing when "shooting wide open"?
That means that the focus wide open mostly is a bit different from focussing closed down.
The Sony then will show the opposite: you focus closed down, and then take the image wide open, giving an OOF wide open image.