Analysing Lights Painfully Slow

[Martin Dowd]

Decided to down load the latest version of ASTAP ( 19th Dec 2024 ) for my next project M42 Orion nebula and ongoing projects into 2025.
Data set is SHO from ZWO2600 MM and Antlia 3nm Filters
Loaded Ha Lights first ( 71 x 2 min subs ) and selected Analyse and organise images
Process was painfully slow , took 45 minutes to analyse ???
Then loaded 40 Darks , darks were analysed in 10 seconds
Then loaded 40 Flats , Flats were analysed in 10 seconds
Then loaded 40 Flat Darks , Flat Darks were analysed in 10 seconds
Created master Dark , took 15 sec
Created master Flat , took 15 sec
Stacked using Sigma Clip average , Stacking took around 15 mins , too long

Then tried my Oiii data set ( 63 x 2 min subs ) analysing took 15 minutes

Any ideas why Analysing Lights is taking so long ??
Previously over the past year or so it took say 5 to 8 minutes to Analyse say 60 lights

Laptop is a 17" HP Omen i7 processor 32GB ram , Windows 10 Pro

Any advice welcome

Clear Skies
Martin

[han.k]

Hi Martin,

There hasn't changed much for stacking. Can you share some lights so I can have a look?

Han

[Martin Dowd]

Hi Han,
I just loaded 60 x Ha lights from my previous project NGC 2070 Tarantula Nebula ( 2 min subs ) and ASTAP Analysed them in less than 5 mins
Admittedly NGC 2070 is a much brighter object across the whole image and substantially more stars , whereas M42 is quite dim with much fewer stars ( only the core region is bright )
Im thinking ASTAP is taking time to analyse M42 due to the 3nm Ha filter and restricted star population ???
How can I send a few fits files ( say 5 off ) to you via this forum ?
I may have to get my son to help me as hes in the IT industry , Im not fully proficient in computer tech

Martin

[han.k]

I assume the star detection has some problems with M42 due to the unequal background. So I assume this is a rare occurrence.

To share just zip a few files in one file and upload them to https://ufile.io/ and share the resulting link. Probably there is not much I can do but still interesting to have a look.

I'm away from home so it will take a few day before I can have a look to them.

Han

[Martin Dowd]

Hi Han,
Please find below link to zipped file containing 5 x120 sec Ha Lights of my M42 project.
When I image from my B8 City suburban location, sky brightness varies greatly from Dusk to Midnight but ASTAP has always performed well during analyzing ,calibrating and stacking ( I generally use Sigma Clip Average )
This M42 project is an unusual one ?

https://ufile.io/wf7m1spr

Look forward to your expertise , evaluation and reply in the coming days

Thanks in Advance

Martin

[Martin Dowd]

Hi Han,
Have you had a chance to look at my M42 subs I sent you 2 weeks ago
Thanks
Martin

[han.k]

Hi Martin,

I have overlooked your post due to the busy schedule here. I will have a look next days.....

[Martin Dowd]

Thanks Han

Regards
Martin

[han.k]

Yes the inspection for HFD is terrible slow. As expected the cause is that the background estimate is too low for star detection inside the M42 nebula. Normally is it only investigates pixels which are 5 sigma above the background. but for these images it is investigating probably 70% of the pixels in a time consuming star detection routine.

I have no solution for this now. I will store the images for later. It would require a smarter star detection or a watch dog timer to abort earlier or a skip for stacking.

Cheers, Han

[Martin Dowd]

Hi Han,
Thanks for identifying the issue
Hopefully a solution can be found for these types of images
Clear Skies
Martin