SharpCap Forums

Hi all

After 5 months of doing nothing (clouds and personal circumstances), I decided to capture ARP 299 again.
It's nice and high now plus I still had all the data from 2021. See my posting from 2021 with info and details about the object.
The original calibration files were lost though so had to improvise with similar calibration files. That's the reason why the image in in grey scale.
Just too much difficulties with colours.

All in all a bit over 18 hours of data. Enough to just see the very faint vertical tidal tail
I'm in Bortle 6/7 here, so it's around the best possible I can manage.
But the direct surroundings of the NGC 3690 and IC 694 pair are very well visible. Also a lot of (fuzzy) surrounding galaxies.
Needles to say I am rather content with the result.

The full un-cropped 3046x3237px version can be found here: https://i.ibb.co/jVpybHk/NGC-3690.jpg

Cropped 1600px version

Also, something there that wasn't there in 2021: supernova SN 2023wrk is from last year and visible in this capture too.
Bortle 6/7
Meade LX200 8" f/10 ACF OTA
Ioptron CEM25EC mount (no guiding)
2021: Baader Neodymium Skyglow filter
2024: Baader IR/UV Cut filter
Zwo ASI071MC Pro camera

Captured with SharpCap Pro @ -10 Celsius / WB 50/50
2021: (109 x 139 sec / Gain 0 / Offset 4) + (38 x 120sec / Gain 120 / offset 8) + (22 x 411sec / Gain 10 / Offset 4)
2024: (41 x 180sec / Gain 0 / Offset 4) + (125 x 240sec / Gain 45 / Offset 4)

Stacked with SiriliC (stacking manager for SiriL)

Processed with Siril and Photoshop
Siril: Histogram, Background Extraction (which was a challenge with so much fuzzies around), Black Point Linear stretch
Photoshop: Starless version, several steps in Camera RAW Filter, NoiseXterminator, levels.

Hi Menno,

very nice - getting decent images of small targets like that with your light pollution shows real dedication.

I had a look at the high res version and downloaded it to have a play as it looked like it might take a bit more sharpening. The barred spiral does improve with a spot of 'fine' sharpening from the SharpCap planetary live stacking, but there is something odd going on in the main galaxies - I'm not sure if it is a result of the processing or the JPG compression. It's odd because it is confined to quite a small area, but clear in that area
What do you think?

cheers,

Robin

Menno

Good image of a difficult target + an interesting write-up.

Dave

Thanks Robin and Dave!

Robin: that is my own fault I see now. Too much stretching. Somehow missed that completely

Menno