Question on the Bahtinov feature

[hdoraisamy]

Hi there

Is there a video that explains how to achieve proper focus using the Bahtinov feature in Backyard EOS? I have listened to many of the youtube recordings but they only touch upon it. I was hoping to see an actual demonstration by someone that shows me how they achieved focus using this.

I do understand that it requires a mask

Thank you

Hari

[admin]

The best way and mostly used feature for focusing is using a bright start and the FWHM live metric in Frame&Focus.  Point on a bright star, adjust focus until you get the lowest number you can get over time. You need to be relatively close to focus to begin with to see your selected bright stars.

[astroman133]

When I first started using BYE, I used both the Bahtinov mask and the FWHM focus metric. They agreed so well that I stopped using the mask and only use the focus metric. This gives two advantages. First I don't have to touch the scope to add and remove the mask. Second, I don't even need to be near the scope to focus.

[hdoraisamy]

5 hours ago, admin said:

The best way and mostly used feature for focusing is using a bright start and the FWHM live metric in Frame&Focus.  Point on a bright star, adjust focus until you get the lowest number you can get over time. You need to be relatively close to focus to begin with to see your selected bright stars.

Thank you! I tried this indoors and noticed that the numbers do jump quite a bit. Is that normal? I will try FWHM tonight since we have clear skies

[astroman133]

If the FWHM number is jumping around too much, you may be able to steady it down by increasing the number of frames that BYE averages together to calculate the displayed value. I believe that the default value is 10 frames. I changed my setting to 15 frames. The setting is in the LiveView area of the Settings dialog and is called FWHM Average.

[admin]

1 hour ago, hdoraisamy said:

Thank you! I tried this indoors and noticed that the numbers do jump quite a bit. Is that normal? I will try FWHM tonight since we have clear skies

FWHM only works with a single star in the zoom box.  If you tried indoors on a well lit daytime object that is never going to work.