The Grus-Quartet from the city - now with RGB

[Slawomir]

Hi all,

This is my second experiment with Lum imaging with a small refractor from Paddington in Brisbane (2 km from Brisbane's CBD).

http://cdn.astrobin.com/images/thumbs/66003105f6eb7c379f788988a24fc232.16 536x16536_q100_watermark.jpg

LRGB version: http://www.astrobin.com/full/312393/G/

Merely 6 hours of Lum data looks definitely better than I expected. This is a simple stack with flat calibration and histogram stretch only. I see I need to redo the flats and also perhaps also do bias calibration. Weather permitting, I hope to soon add an hour of colour per channel.

Thank you for looking!
Suavi

[Placidus]

Amazing. I would not have thought it possible.

Mike

[strongmanmike]

Yeh considering your location..not bad :)....but I'd still get it under dark skies if I were you, will obviously be a big difference :thumbsup:

Mike

[RickS]

Looks great, Suavi! Look forward to the colour version.

[Slawomir]

Thank you all for your encouragement. I'm collecting data for the last (blue) channel as we speak. Not sure if one hour per channel will be sufficient - will find out tomorrow. Yes, I would love to get Lum data from a dark site, but this unfortunately is not possible at this stage.

[atalas]

Very cool seeing the quartet Suavi :thumbsup: look forward to seeing It finished.

[Octane]

I'm working on the same field with the FSQ! Will be interesting to compare final images. :)

Looking great, already!

H

[Slawomir]

Thanks you gents.

It turns out that I need more RGB data, so will need to collect some extra when I will get a chance.

Current quickly processed Lum channel: http://cdn.astrobin.com/images/thumbs/a14315d00004e5baaca8196d0bdc4463.16 536x16536_q100_watermark.jpg

[billdan]

Looks like it will come out looking OK Suavi, you want to be quick with the RGB as the moons getting bigger.

[Atmos]

There are a few nice background galaxies popping through in the top right corner as well.

[Slawomir]

Thank you Bill and Colin.

Just added about 1.5 hr of RGB data per channel. So all up I had just under 11 hours of exposure. Would love more data but I think it is time to start planning another target, this time in narrowband.

In conclusion, LRGB imaging is possible from Paddy in Brisvegas, but decent results require loads of exposure and skilful processing, and I lack in both.

It was an interesting experiment nonetheless.

Astrobin link: http://www.astrobin.com/full/312393/F/

Full res: http://cdn.astrobin.com/images/thumbs/85172fe518ee9d7354bf36eb30510dc6.16 536x16536_q100_watermark.jpg

Thank you for looking!
Suavi

[cometcatcher]

Well done from the city Suavi!

[RickS]

Definitely an interesting experiment, Suavi, and a surprisingly good result under the circumstances.

Cheers,
Rick.

[Slawomir]

Thank you Kevin and Rick for you kind feedback and a very subtle advice ;) I promise I won't try again LRGB imaging from our backyard :lol:

On a slightly different topic, I was quite unsuccessful with my first attempts at colour calibration with the new photometric calibration tool in PI, perhaps there isn't enough RGB data in this image?

http://www.astrobin.com/full/312393/E/

[Atmos]

For RGB imaging in the city, very nice :)

[RickS]

Suavi, did the graphs at the end show the data points nicely clustered along the line of best fit? I've not had a bad result from PCC so far, but I usually have good colour masters based on several hours integration time for each filter.

Cheers,
Rick.

[Slawomir]

One (top) graph was showing a nice trend (stars along the line of best fit), while the second (bottom) graph did not show a clear trend really. I feel RGB data was insufficient.


Glad you like it Colin. Gradients and dust bunnies were quite extreme and took a bit of experimenting to get them under control...

[billdan]

Hi Suavi, just had a look at the LRGB version and its not too bad. Only criticism I have is the pink centres of the galaxies, they should be more yellow. As you say maybe not enough RGB data to get a good colour balance.
I had a lot of trouble with gradients as well when I did them.

[atalas]

Nice Suavi....lots of faint little buggers in the field too :thumbsup: good work from LP skies.

[Slawomir]

Thank you Bill and Louie.

I played a bit with photometric calibration and I feel the galaxies are a bit better balanced colour wise, but now in turn some stars are a tad green...

http://www.astrobin.com/full/312393/G/

[Camelopardalis]

Nice one Suavi :thumbsup: amazed at what you've pulled out of the lights :eyepop:

[Slawomir]

Glad you like it Dunk. Now that I've tried LRGB, there is even a stronger drive to find a convenient and a dark site...

[Ryderscope]

Well done Suavi for working this through to a good result.

[Camelopardalis]

Yeah nothing beats a nice dark site Suavi :thumbsup:

[Shiraz]

an outstanding image from a light polluted site - would be a good outcome from any location. cheers Ray

[Slawomir]

Thank you Rodney, Dunk and Ray.

I had a bit of fun with Aladin - I find it quite fascinating that after plate solving one can click of an faint blob in own image and get instant access to some interesting information about a given dso.

It's fun! :-)

[peter_4059]

Great result from Paddo Suavi. The details in the galaxies are excellent.

[Atmos]

I've never tried doing that in Aladin, might have to give it a whirl when I get a decently deep luminance shot of something :P

[rustigsmed]

nice one Suavi,
are you just using L or a light pollution filter for luminance? I would recommend a CLS CCD or similar - it goes pretty well against LP.
interesting experiment nonetheless, definitely galaxies that are medium brightness and above you're ok.

cheers