Minimum Stars for Registration

Dear Rowland @rowland-f-archer-jr,

I am about to release APP 1.072 😉 it has a further improvement in star analysis and it could be the solution to why some frames failed in your case.

The actual number detected, being a bit above 500 or below should not make a difference. Some images only contain very little stars and APP will register those, if the star analysis works correctly.

Some users experienced difficulties because hot pixels were mistaken for stars and then registration on those frames will fail. I think the new release will solve this and I would think this is the issue that you face as well.

You can check yourself if star analysis is working correctly on those frames, by setting the image viewer to the starmap mode. Please check if APP finds stars were there are actually hotpixels 😉

I will try to release APP 1.072 within the next 24 hours !

Mabula

Hi Mabula - 

OK, I will try 1.072 🙂

I asked because it seemed like only the images with stars just under 500 were marked as "Failed."  I loaded the images and they looked OK.  APP is busy now calibrating frames from last night so I can't easily re-run to see if hot pixels were selected as stars.  

Cheers,

Rowland

It must be an M1 thing as the other day all my M1 images failed, again with an SCT.

Must be a star poor area.

I ran the images again yesterday and all but 2 passed using per session setting.

Hi @rowland-f-archer-jr and @steveibbotson,

Please let me know how APP 1.072 performs, in star analysis, an extra algortihm is added to better discriminate between hot pixels and small stars. In data with a little amount of stars, APP was detecting some hot pixels as stars and that could have been the reason for registration failures.

Some other users shared their data on which APP 1.070 and 1.071 had problems due to a small star count and detection of hot pixels as stars..., and those datasets do work properly now. If it still fails, please share the data so we can further improve this 😉

Kind regards,

Mabula

I will run the subs through again.

I have collected a bit more data since my last stack.

It could be that with using the SCT my stars are also a bit "blobby"

I restacked last night using 1.o73 and at first it analysed and reject a few subs which I agreed with.

Ran the registration with default settings and it rejected them all.

I changed to triangles and then upped the scale stop to 8 (I think) and then manually selected a referance frame.

And with a bit of fiddling in PS.......