Description: HFR (Half Flux Radius) is a useful metric for determining your telescope's focus.  It's important to note that HFR is only relative to other images of the same object through the same imaging train.

To calculate HFR, Right Click on an image within the Sequence Generator Pro display and select "Calculate HFR" (alternatively you can click on the "star" icon in the toolbar).  

The image will then have an overlay of some of the stars used for the HFR calculation.

To view the HFR of the entire image use the Image Statistics Module: