SharpCap Forums

Hi Robin,

The frame brightness and FWHM filters are very useful I find. The other main parameter I use for selection in postprocessing (apart from noise estimation which is based on the background noisiness) is Eccentricity -- which cuts down the number of frames with flared or funny-shaped stars.

Is a global Eccentricity estimation the kind of calculation that can be carried out fast enough for livestacking?

thanks

Tim H

Hi Tim,

yes, actually the eccentricity comes out of the star detection code already, but SharpCap does nothing with it (beyond a very mild filter that throws away stars with very high eccentricity).

If you have some sample frames (good one, bad one, otherwise minimal difference between them) I can try a manual test on them to see if the code is any good at picking up mis-shaped stars or not. That would indicate whether this might work.

cheers,

Robin

Hi Robin,

Thankyou. That would be great. Attached here are 10 FIT files of the core of M92.

https://onedrive.live.com/?id=330584F8B ... F8B152FA32


All were selected (by PI subframe selector) as FWHM <2.4 and Stars > 80 (using star number as a 'brightness' indicator). They probably represent a pretty tough test since they are quite noisy and only 0.2s exposure time (at ca F 4.2). If they are too difficult I can easily send some that are less noisy .

The first 5 were further selected for Eccentricity < 0.60 and the latter 5 for Eccentricity > 0.80. The difference is quite apparent visually so they should make for a fair test set.


Tim