Consider adding a specifiable delay between focuser moves and image capture in autofocus


#1

I have a suspicion that when my focuser moves the big mirror in my RASA it takes a bit of time for small vibrations to settle. I cannot prove this, but it seems likely and might explain some non monotonic focuser values I see. I propose an adjustable delay be added, that defaults to 0 and allows a range of at least 10 seconds – although I see no reason other than screen real estate to impose a particular upper bound.


#2

I second this for sure. I think that additional delay is essential in getting the best possible settled results. I don’t know what kind of delay we are seeing between the time the focuser moves to a new position and the actual image integration but I think that it is also affecting my focus runs. I thought of this very early in adopting SGP. Thanks for bringing this up.


#3

I hava a strong stepper on my setup, so a delay after focus move is a very helpfull thing.


#4

This is a device specific thing and so belongs in the driver controller, not the application.


#5

I didn’t realize this had already been requested. Yes - this is an important feature and it should be part of the autofocus routine the same way it is there for mount slews. The focuser has no idea how long the overall system will take to settle - only the user and the orchestrating application can tell.

You want it to be as fast as possible - but for at least one of my cameras, the same focuser but a different camera just won’t work with the autofocus routine due to smeared stars. It isn’t just a matter of making sure the focuser has stopped - it’s about letting the system settle - especially when near focus and the stars are very small - and sensitive to slight motion.

Frank


#6

Like I wrote in the other thread, an user selectable delay after focuser moves would be very nice to have for me.
While I can understand Chris’ point that this is something device specific, I still think that it belongs into SGPs profile settings, since you may want to change e.g. your imaging camera which may need another focusing settle time. The focuser itself is not aware of that change, but in SGP you could simply switch to another profile and all settings would be taken care of.


#7

Just bumping this. Are there any considerations to implement a “wait for the imaging system to stabilize after focuser move is completed”-setting?


#8

After contacting the manufacturer of my focuser, they implemented this into the driver.
Two nights of testing and it just works great!
While I think for some users this is not optimal (those who switch between different cameras), I would really encourage all having this problem to contact the manufacturer of their focuser and ask for this function!


#9

Who is the manufacturer of your focuser?


#10

Most of the time when doing an AF run on my SCT I get the “not within 10% of the expected HFR” warning message. Right after that message closes I zoom in 200% on the validation frame and take an exposure (same binning and length) using the Frame and Focus module, and keep an eye on a small fuzzy star and watch the image change to see a much more in focus star. I also use the “Star HFR” button and see the HFR get better on the stars being measured. This is repeatable 100% of the time. A short delay after moving the focuser, and before starting the next AF exposure would allow auto focus to be useable with my SCT. As of now I need to do the focusing with the Focus Control module.


#11

It is a USB_Focus v3.
Did you try longer exposures?


#12

Yes. Right now I’m at 5 sec but have tried as much as 2 mins. 2 mins is way too long for the Atik 383L+.


#13

I use the Atik 383L+ OSC and do all of my focusing and Plate Solving using a 3x3 bin @ 5 seconds and have not had any issue. However, I’m using a Optec TCF-S focuser so I’m not moving the mirror.

mahaffm


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