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images of M51 from LP. Advice/experience requested.

ollypenrice

By ollypenrice
in Imaging - Discussion

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ollypenrice

ollypenrice

Posted
Posted

Hi all,

I'm working on an article about imaging M51 and would love to hear from you if you've managed to catch the tidal extensions in any kind of LP.

I don't have any significant LP so I don't know what's possible. I've seen plenty of M51s from LP so the galaxies can clearly be done, but have you had any luck with the outer halo from an imperfect site? If so I'd be delighted to hear from you.

Thanks in advance,

Olly

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Daniel-K

Daniel-K

Posted
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Hi olly i live in on the edge or liverpool were the LP is bad but not as bad as in the center i have mange abit of the halo on the NGC galaxy but not to sure on M51 its self heres a pic hope this helps 4 hours with a dslr under 50% moon

post-6284-0-73617200-1361958657_thumb.jp

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Jessun

Jessun

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My M51 from last year was taken over 3 nights in March, 7 hours in total, 84 five minute subs with the RC at f8/1.6m mounted on the trusty ol' HEQ5 out on the balcony. It might as well have been taken from Picadilly Circus in London, LP is nearly as bad in central Lyon. Only a UV/IR block filter used.

I never posted this one I don't think, since the processing on my stack was done by a fellow SGL member. We can call him HP. PixInsight is a good guess for the processing. It's also probably a coffe break job - so not something HP might want to stick his badge on as such. And neither can I really - so the data is in intellectual rights limbo :grin: !

gallery_16323_2313_2556814.png

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Shibby

Shibby

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I don't know if this is useful or not, but here's what I got from SGL7 at Lucksall Park, which is a "moderately dark" site with some, but not lots of, LP. With the second image, I've forced the issue and I think the streams are just beginning to show.

This was with 5min subs... longer exposures and many more of them should help separate the signal from the LP, I think this is an important consideration when shooting through LP. Logic (perhaps flawed?) tells me that even the faintest objects should add a few extra photons, even when through LP, so with enough subs you can eventually start to seperate that signal out assuming you can expose for long enough to collect those few extra photons. Which, of course, you can't if the LP is particularly bad...

post-5051-0-35929300-1361969481_thumb.jp

post-5051-0-98517500-1361969489_thumb.jp

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IanL

IanL

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Here's a poor example, but one of the few I managed to successfully guide my 8" 2M focal length SCT before wimping out and switching to imaging the easy to guide 80ED (and when it has been cloudy!). It's 10 x 300s exposures, unmodded DSLR.

Moderate to fairly poor light pollution to the north east through south west, depending on humidity really. Pretty dark in other directions over the sea. No direct LP nearb except one neighbour's random security light. The killer on this one is that it was full moon, and it was up and blazing away when I shot the subs. (Due to weather I will take whatever I can get). It's not great but shows you can get something in even the most adverse condition.s

post-18840-0-90553500-1361972961_thumb.p

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IanL

IanL

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Sorry for the poor spelling and grammar by the way, was in a rush to get somewhere! I should also have said there is an absolute killer gradient on the subs due to the moon, but DBE in PixInsight did a great job of neutralising it without wiping out all of the faint fuzz.

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ian_bird

ian_bird

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Hi Olly

Here's my effort from the center of Windsor - with the neighbours white painted house lit up like the Titanic (Before it sank obviously).

My 10" RCT. 2000mm SXVR-H18. 4x5 min RGB, 20x5min L. Processed by Nik Szymanek - which explains a lot.

Cheers

Ian

post-26501-0-18332200-1361993331_thumb.j

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  • 4 weeks later...
ollypenrice

ollypenrice

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Thanks. I wrote the imaging article and there are two images, one from our dark site and taken by myself and Yves van den Broek and another taken by Jessun (as he's known here) from his balcony in the blazing lights of central Lyon. Jessun's is a hell of a result in my book. From here we have it easy with a mag 7 zenith.

It's Astronomy Now.

Olly

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nytecam

nytecam

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Thanks. I wrote the imaging article and there are two images, one from our dark site and taken by myself and Yves van den Broek and another taken by Jessun (as he's known here) from his balcony in the blazing lights of central Lyon. Jessun's is a hell of a result in my book. From here we have it easy with a mag 7 zenith.

It's Astronomy Now.Olly

Thanks Olly - I only had a quick scan in Tescos newsstand but couldn't find the author! Again well done.
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Jessun

Jessun

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The processing is not mine as I mentioned above, but that is not a big deal in this context, as Olly's section in the article should inspire more budding imagers to aim for targets like this - and persist! Bright as it may be in comparison, time, time and more time does pay off. 7 hours at f8 is really not a lot of data.

I thought I'd lost this stack on a crashed HDD, but luckily found it again on a backup, so one murky evening I'll run through a reprocess for practice.

Mag 7 by the way is something I can only Google here in the disco smoke.... :Envy:

/Jesper

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Sp@ce_d

Sp@ce_d

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NIce one... picked up my copy yesterday.... you want to tell that bloke to stop putting his head in front of the scope when you're trying to image though Jessun... spoils the picture... :grin: :grin: :grin: :grin: :grin: :grin: :grin:

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ollypenrice

ollypenrice

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NIce one... picked up my copy yesterday.... you want to tell that bloke to stop putting his head in front of the scope when you're trying to image though Jessun... spoils the picture... :grin: :grin: :grin: :grin: :grin: :grin: :grin:

What???? C'mon, the mag needs the odd pin-up guy. S at N have got Brian May and Brian Cox so Astronomy Now need old Chrome Dome in all his aged glory...

:afro: lly

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Sp@ce_d

Sp@ce_d

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What? C'mon, the mag needs the odd pin-up guy. S at N have got Brian May and Brian Cox so Astronomy Now need old Chrome Dome in all his aged glory...

:afro: lly

:grin: :grin: :grin: ... might be one image you don't mind clipping a few pixels on Olly... :eek:

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cp255

cp255

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I live in NYC suburbs. I image using a Baader Moon & Skyglow Filter and I can just barley get the tidal extensions. I can see them when I am stretching the image however by the time I am done removing the background sky glow most of the tidal extensions have been lost in the noise.

http://rawastrodata.com/dso.php?type=galaxies&id=m51

Look at the second image. I left more noise in the background but you can also see more of the tidal extensions.

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