M101 Pinwheel Galaxy

[Gerr]

The Pinwheel Galaxy is my first DSO target after some hiatus due to the great British weather. I have not had the opportunity to use my Sky Watcher 200P reflector telescope for over 8 months!!

Conditions were good over the last couple of nights with no wind, rain, clouds or even a bright Moon to spoil the show.

So I pointed the telescope straight up at M101 and started taking light frames with my Zwo Asi294MC pro.

Yes, I had a few issues with trying to remember how to run the various software applications harmoniously together on my 'astro computer'. The only persistent problem was dithering so that was switched off (tracking went haywire after every dither!!).

In the end I managed 7hrs of imaging time on this target and put all the data (including calibration frames) into DSS which produced a fair looking result.

This was put through the Photoshop CS Suite to produce an image that is my best yet of this galaxy!!  Chuffed!!!

Hope you like, CC's welcome.

Image of M101 Pinwheel Galaxy (25 million light years away in Ursa Major): 

[Cozzy]

Very nice indeed, You have every right to be chuffed with it, you worked hard to get that data. I get the feeling there is still more data to pull out of the image.

 

[Gerr]

Hi Cozzy,

Yes - I went back to the image data and this time ran it through Siril which seems to be better at stacking and preserving image details. I did background extraction and colour calibration before stretching using hyperbolic transformation tool.

I then exported into photoshop to finish it off (star extraction and RAW camera filter) with some gradient removal tools.

I think the result is better.

 

Gerr. 😀

 

[tomato]

Nice M101. I prefer the second image, the fainter spiral arms are much more distinct.

[AstroMuni]

3 hours ago, Gerr said:

I did background extraction

Check out GraXpert AI too. Sometimes it does a better job at extracting the background as compared to RBF in Siril (btw, RBF is from GraXpert and incorporated into Siril)

[Cozzy]

Gerr,

That’s a very nice image, quite a substantial jump in drawing out the detail, the core also looks less dominant in comparison to the first iteration.

Justifies the hard work you put in getting the data in the first place.

👍

[Gerr]

4 hours ago, Cozzy said:

Gerr,

That’s a very nice image, quite a substantial jump in drawing out the detail, the core also looks less dominant in comparison to the first iteration.

Justifies the hard work you put in getting the data in the first place.

👍

I could sharpen it further and improve contrast more but where do you stop!! 😂👍

[ollypenrice]

It's very good and the colour is far more accurate than the bright blue spirals which we often see with M101.

The core is saturated in the first one and still saturated, though less so, in the second. The first thing I'd want to do is look at the core in the linear data. Is that saturated?  If it isn't, there is no need for it to become saturated during the stretch. You just need a better stretch, or a blending of two stretches. Maybe just a hand-shaped stretch in Curves would do it. What does the linear core look like?

Olly

[Gerr]

9 hours ago, ollypenrice said:

It's very good and the colour is far more accurate than the bright blue spirals which we often see with M101.

The core is saturated in the first one and still saturated, though less so, in the second. The first thing I'd want to do is look at the core in the linear data. Is that saturated?  If it isn't, there is no need for it to become saturated during the stretch. You just need a better stretch, or a blending of two stretches. Maybe just a hand-shaped stretch in Curves would do it. What does the linear core look like?

Olly

Hi Olly,

Core isn’t saturated in the linear data. I guess I like the centres bright as long as I don’t obscure the dust lanes. A number of processing connotations can be followed dependent on your ‘artistic’ side. It’s what makes astro processing so difficult as there is no hard and fast rule to follow - whatever looks good I suppose!! 😂

Thanks,

Geraint.

[ollypenrice]

13 minutes ago, Gerr said:

Hi Olly,

Core isn’t saturated in the linear data. I guess I like the centres bright as long as I don’t obscure the dust lanes. A number of processing connotations can be followed dependent on your ‘artistic’ side. It’s what makes astro processing so difficult as there is no hard and fast rule to follow - whatever looks good I suppose!! 😂

Thanks,

Geraint.

I'm not sure I agree. Not destroying information in processing is as much scientific as artistic and going from unsaturated to saturated does destroy information.

Olly

[Gerr]

1 hour ago, ollypenrice said:

I'm not sure I agree. Not destroying information in processing is as much scientific as artistic and going from unsaturated to saturated does destroy information.

Olly

Hi Olly,

I see your point and it is easy to overdo the saturation in processing without too much effort!!  I had another go at this and maybe this image shows where you are coming from better but to my eyes it is a fine line indeed to tread.

The M101 core re-done (better hopefully)??

Geraint.

 

[ollypenrice]

10 hours ago, Gerr said:

Hi Olly,

I see your point and it is easy to overdo the saturation in processing without too much effort!!  I had another go at this and maybe this image shows where you are coming from better but to my eyes it is a fine line indeed to tread.

The M101 core re-done (better hopefully)??

Geraint.

 

For me, way better. We can now trace spiral detail much further into the core.

Olly