Focusing question

[cmjrff]

Dear Group:

I am still a relatively new user of BYeos and I am having a ball with it.  I've tried several times to achieve focus using the Frame&Focus tab but after getting a star as focused as possible, I switch to using a preview (1 second exposure) and my bhatinov mask.  I always have some tweaking left to do with the mask to achieve my best focus.  In fact, when I check the Frame&Focus tab after using the mask, the number is lower than I was able to achieve without the mask using only the Frame&Focus function.  I'm wondering if there is an option to use a longer looping exposure with the BackyardEOS focus tool?  Or I am interested in any other suggestions.  Many thanks,
Charles

[admin]

Seeing?

 

Keep in mind that there is no absolute focus position.  In fact every setup has what is called a critical focus zone and as long as the your are within that critical focus zone it you are focused.

 

I'm like you... or use to be;  I liked to confirm my focus with a Bahtinov mask.  However, I have found over the years that the FWHM I get from my initial focus routine yielded perfect focus 99% of the time and now I don't use the Bahtinov anymore.  Get the lowest number possible and you should be fine.

 

Can you post an image of your Bahtinov mask result before adjusting focus; after you achieved focus using FWHM only that is?

 

Hope this helps.

[astroman133]

Charles,

 

If the FWHM focus value is jumping around quite a bit due to seeing, you may be able to steady out the value by increasing the FWHM Average value in the Live View settings group on the Settings dialog. The default value is 10 frames, but I have bumped that up to 15. For me, that seemed to improve the LiveView focusing.

[cmjrff]

Thank you to all who responded.  I'll post a bahtinov image after focusing with FWHM (if it ever clears up again!).  And I will also try to bump up the number of frames in the Live View settings.  Something tells me that will help a lot.  I'll post back when I know more.
Charles