M101 reprocessed from 2020 data

[JohnH]

The data for this image is from 7th April 2020. As I always seem to do I imaged this under a full moon. There are a huge number of other problems with the original data:

a) My Sharpstar 15028 HNT was very sick. I was trying to find the back focus and this was way out.
b) Collimation was way out.
c) Possibly because of the back focus the stars are actually small streaks rather than blobs.
d) For some reason I only took RGB subs, no L. Maybe it was because the Moon was so bright it swamped the image. I have created a Pseudo L by adding the RGB masters in Pixelmath.
e) There is no Ha data because I did not have a filter at the time.
f) I did not take enough data.

That being said, I do have an image.

I plan to do this subject afresh when (if) I have an observatory up and running - the planning decision should be within the next two weeks. Then I can order the observatory and wait for it to arrive. Then we will obviously have solid cloud, erupting volcanoes and massive asteroid impacts for several months.

Details:
R: 60s x 30
G: 45s x 30
B: 45s x 30

Processed: Pixinsight WBPP, Pixelmath for Pseudo L, BlurXTerminator L, NoiseXTerminator L, RGB combined,  Spectrographic Colour Calibration, BlurXTerminator for RGB, LRGB combination, exported to GraXpert for gradient removal then reimported to Pixinsight, StarXTerminator, GenrelisedHyperbolicStretch (GHS) on
stars and galaxy images. Imported to Affinity Photo 2 where the stars were toned down before merging the images and applying a High Pass Filter for detail contrast.

John

[Carole]

Almost missed this one John.  It's a difficult target even in dark skies let alone Bromley.  I still see problems with the stars all with big halos round them.

Did you ever sort your star spikes problem?

Carole

[JohnH]

Hi Carole,

I think my stars are improving a bit since I took this. The area around M101 is full of galaxies, I was very surprised when I plate solved this image and overlaid the result. Some of these halos are really there.

When I captured this data the spacing between the reducer and the sensor was WAY off.

Regards,

John