Jump to content

sgl_imaging_challenge_2021_2.thumb.jpg.72789c04780d7659f5b63ea05534a956.jpg

M51 The Whirlpool Galaxy


Recommended Posts

M51 an extreme crop from a larger frame. Imaged from Spain with The 17in Planewave unguided with the L500 mount and Moravian 16803 G4.  LRGB all 300s subs, 3hrs Luminance 4hrs each in RGB.

Processed with Pixinsight and Photoshop


Thanks for looking
Peter

M51 LRGB.jpg

  • Like 33
Link to post
Share on other sites

Thank you everyone for commenting. To be honest this mount makes unguided imaging so painless. Its a huge bit of kit weighing nearly 200Kg in total, 3meter focal length, and it slews around like its carrying nothing.... 20 degrees a second is its slowest setting (60 fastest).... Planewave have got it spot on. The software is easy to use creating a model was very simple and polar alignment was a doddle..... However I did put my back out for a few days when installing the thing though 😂

  • Like 2
Link to post
Share on other sites
8 hours ago, peter shah said:

M51 an extreme crop from a larger frame. Imaged from Spain with The 17in Planewave unguided with the L500 mount and Moravian 16803 G4.  LRGB all 300s subs, 3hrs Luminance 4hrs each in RGB.

Processed with Pixinsight and Photoshop


Thanks for looking
Peter

M51 LRGB.jpg

Seriously good M51 Peter! Amazing to think that image wasn't guided! 😲 

Quick question - most LRGB imagers seem to go for parity between their L and RGB, but in this case you have gone for a quite drastic reversal of 4:1 ratio in favour of RGB. Any particular reason why? Is it because dark skies favour RGB over LRGB for quality, rather than speed? I know that creating a synthetic Luminance from RGB over using a true Luminance can be beneficial in terms of smaller stars and perhaps slightly sharper details (at the expense of faint detail). Is that anything to do with it? 

  • Like 1
Link to post
Share on other sites
Posted (edited)
5 hours ago, Xiga said:

Seriously good M51 Peter! Amazing to think that image wasn't guided! 😲 

Quick question - most LRGB imagers seem to go for parity between their L and RGB, but in this case you have gone for a quite drastic reversal of 4:1 ratio in favour of RGB. Any particular reason why? Is it because dark skies favour RGB over LRGB for quality, rather than speed? I know that creating a synthetic Luminance from RGB over using a true Luminance can be beneficial in terms of smaller stars and perhaps slightly sharper details (at the expense of faint detail). Is that anything to do with it? 

It was 4rs in R, 4hrs in G, 4hrs in B and 3hrs in L, so a total of 15hrs..... It was supposed to be 4hrs in each filter but I wasn't able to complete the data set with all of the bad weather this season in Spain. There was enough signal in  what I had so decided to process incomplete..... I did actually process fully the RGB before I finished collecting the Luminance but decided to continue grabbing more for it as I though it would benefit. 

There is a clear difference in noise between the RGB and the LRGB... Deconvolution seemed significantly better on the actual  Luminance over a pseudo Luminance I created showing less artefacts.

1684345294_LRGBVsRGB.jpg.55b5ac6cd644f2ae61a01484b883d46c.jpg

Edited by peter shah
  • Like 3
Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
  • Recently Browsing   0 members

    No registered users viewing this page.

×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue. By using this site, you agree to our Terms of Use.