Hy,
imaging went so-so. Seeing was horrible (for my site), but I got almost 6 hours on LDN1584. Will have to see.
Yes, that is what I sugested. As Chris wrote, it is one standard way of handling backlash in absolute position units:
It has the advantage that any value larger than the actual backlash will give you correct performance (maybe at the price of moving too much). This is however different from the BL handling within the focus units themselves. They usually move the additional amount if the direction is changed, and then change the reported position. This one only works correct if the amount you specify is exactly the BL. So IMO it is even superior to the driver-supplied BL.
In principle it's something that should be in the general focus module, a radio button to activate the always-end-with-inward-movement behavior, and an amount for the overdrive (because that can largely vary depending on the focuser). (I had tried to change the focus movement code to implement this, but I don't speak C++ and gave up quickly
)
I'll have a look. Maybe it's easier to test/modify in the focus module
While you're right in principle, with a large BL that can get extremely unhandy for the refinement steps, even more if you still take measurements at each of those positions. That is why I'd prefer to have this as a separate configuration option. And ideally (as pointed out above) not even in (your) focus module, but in the general focus driver - then
all focus algorithms will benefit.
Yes indeed, it did. It's not a desirable thing, as you point out. I might try to look at that again - but maybe you can also investigate how to implement that correction type in the general focuser class?