SharpCap Forums

I been using Sharpcap mainly for polar alignment. Last night I tried to the Focus tool to capture a lunar image.

As you will see from the screenshot below the focus value stayed on zero while the focuser was adjusted.



I am obviously doing something wrong. Could you let me know what!

Hi,

if you look at the mini histogram on the right, you are using a strong display stretch - this is making the image of the moon onscreen look OK when it is in fact badly under exposed. It's far enough under exposed that all the pixels in your selection area are falling below the 10% black threshold, meaning that they are ignored for focus calculations, leading to a score of zero.

Hope this help,

Robin