Originally posted by BigMackCam Yep, the Q7 has those three options also...
On my original flavor Q, I have only two options: Enable, Disable.
All this does is allow shutter speeds shorter than 1/1000 with the electronic shutter when enabled. At speeds longer than 1/1000 it will always use the leaf shutter, when attached.
So unfortunately with the original Q the leaf shutter can not be disabled.
As far as the vignetting, I actually posted a thread about it on 05-1-2015: (before I lost access to that account)
Pentax Adapter Q for K Mount Lens vignetting at faster speeds - PentaxForums.com
This was my conclusion which I double checked. Lenses ranged from 300/2.8, 400/4.5 up to 1000/8 and 500/8 reflex:
"I was able to compare mine with another brand new genuine K->Q adapter and the results were the same. The effect is mostly visible at 1/800 -1/1000 and with high contrast settings (like Bold Monchrome) on the Q.
I conclude that it's in the nature of the leaf shutter at such a high speed, and 1/1000 is very fast for a shutter of this type.
If anybody wants to try, compare 1/1000 vs 1/1250 at which point only the electronic shutter is used.
You will see that there is uneven illumination causing a sort of hot spot in the center."
Just FYI. I don't use the genuine adapter with the super tele lenses.