M51 - Learning some new tricks

[Catanonia]

I have been imaging for many years, but there is always time to learn some new tricks with old data.

So I picked up a BlurXterminator trail and learnt the new spectro / gaia colour calibration routines and put it to work on my M51 data I collected last year with my RC10

I am blown away with the improvement learning these 2 routines have given me with the image below.

I did not even take my time on this processing, probably about 1 hour

 

Deconvolution as always been a dark art for me, and I have never done it on my linear images and have therefore always suffered. BlurXTerminator (if used carefully) just takes this whole hassle away.

 

Details

• M51 13 hours from Bortle 6 skies over 3 nights
• Scope - RC 10 F7 2000mm FL on a EQ8R-Pro
• Camera - ZWO 2600MC Pro OSC and no filters
• ASI Air Pro and 120mm OAG guide
• 7.3 Hours in 2m subs OSC
• 5.6 Hours in 5m subs OSC
• Processed entirely in PixInsight

Edited February 22, 2023 by Catanonia

[Vroobel]

It's one of the best M51 pics I ever saw. 

And now I really don't know whether to go into 2600MM + narrow filters or 2600MC (also with some filters like L-eXtreme). 😳

[Catanonia]

1 minute ago, Vroobel said:

It's one of the best M51 pics I ever saw. 

And now I really don't know whether to go into 2600MM + narrow filters or 2600MC (also with some filters like L-eXtreme). 😳

Thanks

It is a hard decision. OSC is much easier if you are new to it all, but Mono will give better results.

I used to use mono, but the switch to OSC with modern camera's makes the hobby much more rewarding for me with limited night sky time due to the horrid weather in the NW of England.

I have the lEnhance filter too, that I can use (not in this image) if I image large nebula's with my RASA8, but that filter will loose you star colours and the blue in the nebula's

 

[Vroobel]

I'll send PM. I think it's wider subject, I live in Liverpool, so you understand... 

[ONIKKINEN]

Thats a nice M51, but i think there is more to be taken out of the image if you do somethings a bit differently.

Looks like BXT has only tackled the core/very high SNR regions and so there is a "disconnect" in the visible levels of detail in the sharp core and soft everywhere else on the galaxy. Try integer resampling at least x2, probably x3 and you will get a much sharper image. BXT will not sharpen the soft parts of the image because from its perspective the too high a resolution image has nothing to sharpen. That said, my limited understanding of BXT is that it prefers not quite properly sampled images to properly sampled ones, so you might want to be a little bit oversampled for BXT to do its thing best. But still at least 2x or 3x integer resample will work.

[Catanonia]

4 minutes ago, ONIKKINEN said:

Thats a nice M51, but i think there is more to be taken out of the image if you do somethings a bit differently.

Looks like BXT has only tackled the core/very high SNR regions and so there is a "disconnect" in the visible levels of detail in the sharp core and soft everywhere else on the galaxy. Try integer resampling at least x2, probably x3 and you will get a much sharper image. BXT will not sharpen the soft parts of the image because from its perspective the too high a resolution image has nothing to sharpen. That said, my limited understanding of BXT is that it prefers not quite properly sampled images to properly sampled ones, so you might want to be a little bit oversampled for BXT to do its thing best. But still at least 2x or 3x integer resample will work.

Yes noticed this myself. Will give your suggestion a go and see what happens. 

Can you simply integer resample the integration of the OSC after calibration and debayering, or do I need to split it into LRGB ?

[ONIKKINEN]

Just now, Catanonia said:

Yes noticed this myself. Will give your suggestion a go and see what happens. 

Can you simply integer resample the integration of the OSC after calibration and debayering, or do I need to split it into LRGB ?

No need to split afaik, just split the iamge that the stacker spits out before processing anything on it and you get the most bang out of the binning process. (integer resample = Bin)

[Catanonia]

37 minutes ago, ONIKKINEN said:

No need to split afaik, just split the iamge that the stacker spits out before processing anything on it and you get the most bang out of the binning process. (integer resample = Bin)

I re-did with a 2x integer re-sample. The colours are slightly different as I might have added a little more saturation.

It makes a "small" difference

[ollypenrice]

This is a serious M51. I think the last one is the best but over-saturated in colour, for my taste. A dead easy fix if you agree. What's really nice to see is that you have the blue extension of the extended arm after it has passed the companion galaxy. I always see that as a good test.

Isn't the image flipped horizontal?  (I'm terrible at this!)

lly

[Catanonia]

35 minutes ago, ollypenrice said:

This is a serious M51. I think the last one is the best but over-saturated in colour, for my taste. A dead easy fix if you agree. What's really nice to see is that you have the blue extension of the extended arm after it has passed the companion galaxy. I always see that as a good test.

Isn't the image flipped horizontal?  (I'm terrible at this!)

lly

Thanks Olly, this BXT function is very good on certain types of images at bringing out structure.

But it's greatest benefit for me is simplifying deconvolution that I have never done due to the varied and long / messy methods of doing it.

I have no science data on BXT, but I recon it effect takes me from a Bortle 6 average seeing site to perhaps a Bortle 4 good seeing sight. Who knows.

I dropped the saturation a little and flipped it to look like the standard orientation for M51 - So used to horizontal flipping, I forgot this was taken on the RC 10 and not the Rasa

 

Edited February 22, 2023 by Catanonia

[MKHACHFE]

It puts my M51 attempt, taken at 300mm, to shame. 

Amazing work mate. Beautiful