sgp autofocus and guiding

[iwols]

hi just had a quick go at autofocus with sgp and electronic motor focusing,but the star disappeared before it could finish autofocus setup,just wondered if people set guiding first or is there some settings that need altering in sgp to speed up focusing,how long  does it usually take when focus is just about set before using autofocus setup...thanks

[Starlight 1]

4 minutes ago, iwols said:

hi just had a quick go at autofocus with sgp and electronic motor focusing,but the star disappeared before it could finish autofocus setup,just wondered if people set guiding first or is there some settings that need altering in sgp to speed up focusing,how long  does it usually take when focus is just about set before using autofocus setup...thanks

When auto focus is running it turn guiding off . if I have good focus to start with then 2 or3 mins,

[iwols]

thanks starlight but with my ed80 and 414 ccd the star has moved too far in that time cheers

[Starlight 1]

but  it still leave tracking on ,and reset guiding after the focus is done , its still have to have stars in the same place . are so are you tracking or useing PHD at the same time ,as its PHD that get turn off.

[Uplooker]

What software are you using for auto focus? Is it FocusMax?

[iwols]

its sgp ian

[gnomus]

Are you using another scope to guide or an OAG?

[Starlight 1]

What do you have in control panel under auto guide , I have second one down and last one as on.

[iwols]

using an st80 with phd but not using phd at the time as i wasnt pa aligned,just wondered if i should be using guiding when autofocusing

[gnomus]

To answer your other question - for my LRGB filters I use 5 sec exposures at binx2.  I have a 9 step routine.  It takes a couple of minutes to run.  This is a guess - I've never timed it.  SGP measures the HFR of a whole bunch of stars in the frame, not just one star.  Nevertheless, I suppose you want to be using the same star field (or as near as you can).  If this is changing significantly over the length of the focus run, perhaps your polar alignment needs tweaking.

[gnomus]

I think you've answered your own question.  If you are not polar aligned then AF will probably not work.  I would have autoguiding on during focus runs with your set up.  The option to switch it off is there for folks who are using an OAG.

[iwols]

thanks gnomus think that answers my query cheers

[gnomus]

NP