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M51 last night

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Good Evening. Stayed up late last night as was new moon and pointed my set up at M51 - Whirlpool Galaxy in Ursa Major. Left things going until 3 am this morning by which time I had taken the best part of 100 subs, each of 3 minutes in length - sky was quite clear, but there must have been a lot of moisture hanging around as 3 minutes left the images looking very orange from the light pollution. Applied my masterdark and masterbias frames in PixInsight followed by processing in the same software. After trawling the internet for tutorials on how to sharpen the finished image, I finally applied a Linear Transformation which really made the image stand out. Below is the result... I really like the fact that in addition to the main focal point of M51, there are a number of smaller, fainter galaxies hanging around in the background. Really gives a sense of scale of just how big Space is.

56df47e802b5a_M51WhirlpoolGalaxy-sharpen

Have just ordered an IDAS LP filter to try and get my exposure times above 3 minutes without them being washed out. I've read some very favourable reports on these so am looking forward to trying it out - should arrive tomorrow ... just in time for the rain!! 

Clear Skies

Richard

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Wow, lovely image. I agree that the other galaxies in the background really give a sense of scale... Well done.

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Excellent image.  Did you use your canon 500D for the image and if so what ISO did you use for a 3 min exposure.  The stars are not blown at all ?

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17 minutes ago, wornish said:

Excellent image.  Did you use your canon 500D for the image and if so what ISO did you use for a 3 min exposure.  The stars are not blown at all ?

Hi wornish. Yes I used the Canon attached directly to the 2" focusser. I use ISO 800 which for 3 mins takes the exposure histogram to around 30-40% which from reading other posts on this site is about the max for good post processing (although I have had this up to 60% and managed to extract a decent image). 

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Faboulous image

Though i have improved in my imaging i just cant seem to get that "gloss" factor

I do need to learn more about processing

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Great work I love this high,y detailed wide view of this target great stuff 

pat

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1 hour ago, goose35 said:

Faboulous image

Though i have improved in my imaging i just cant seem to get that "gloss" factor

I do need to learn more about processing

Hi, not sure what processing tool you are using so this may not be relevant but thought I'd post my experiences in case others find it helpful. I use Pixinsight and just yesterday was trawling the internet for processes for sharpening images. On the Pixinsight forum (Pleiades Astrophoto, S.L.) I found a thread describing how to use the Multiscale Linear Transform (MLT) tool after searching for "sharpening and making images pop in PixInsight". I followed the settings that a helpful soul had posted and that really helped. I didn't use the exact same settings, but played around in real time preview mode until I was happy - I've attached a screenshot I took from my iPhone to remember the base settings. To be honest, I don't fully understand the processing "detail" behind a lot of these functions, but I use a trial and error approach to see if they help me get images I'm happy with.

IMG_2892.thumb.PNG.e6fbf3212593852c18704

Other than that, to get the really glossy, almost noise free background, my suggestion from my limited experience (got my scope back in September last year so it's been a steep learning curve) is the following:

  • Take as many subs as you can (the image above had 95 subs)
  • Use a Bahtinov mask and spend time to get the focus bang on - I got mine for about a tenner on eBay from a guy who cut them himself from black plastic and it works a treat - saves me ages in getting focus which means much more imaging time.
  • Be ruthless in getting rid of any subs which have any scope wobble - this is the hard part. You've spent all night grabbing as many photons as you can, missing out on valuable sleep, only to chuck some of them away!
  • I use guiding to try and minimise the stuff I need to chuck away and I also use dithering between individual shots - guiding made a massive impact to the percentage of subs I can use (increased my success rate from roughly 30% to 95%+) - dithering really helps cut down on the background noise which means you can stretch the image more before you get to the point where the background becomes noisy (less glossy in your words).
  • Take as long exposures as you can, without overexposing and washing them out or risking too much wobble. My preferred exposure time is currently 3min which is the point at which light pollution is at the limit to get a good processed image from my location (I have just got my LP filter in the post this morning so I hope to increase that significantly :blob7:)
  • Finally, keep a light touch in the post processing. 
  • Above all, enjoy what you're doing. I'm still amazed that I can not only see these objects live in my scope (albeit often a fuzzy blob) but I can now produce images which simply blow my mind from my back garden, less than 30 miles from the centre of London.

Clear Skies

Richard

 

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17 minutes ago, iwols said:

great is it cropped much

Hi. Not a great deal, just enough to get rid of any ragged edges from the stacking process for the slightly offset dithered images. This is pretty much my FOV with my set up. 

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How many galaxies are in this picture? So far I've spotted 3, the two main ones and then a faint one up and to the right. 

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17 minutes ago, Herzy said:

How many galaxies are in this picture? So far I've spotted 3, the two main ones and then a faint one up and to the right. 

At the last count I think it is about 8. The two main points of the subject, one just to the lower left of the main subject, one top left (orange wish tinge), three (?) top right and maybe the smudge which looks like a big star lower right. There might be others too as in the full res image which is too large to post, there are several very faint smudges lurking in the background. 

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