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M27- lets see your pictures.


pyrasanth
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I managed 20 subs of M51 last night with the RASA & Atik 490 OSC but the weather has been really unkind. I only got 1 hour of cloud free sky....& when I went to work this morning.....not a cloud in sight..........makes me sulk.

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FWIW here's my M27 from data gathered over a lot of nights in April. It's 3 x 600s, 14 x 480s, 9 x 360s, 6 x 180s (3hrs 34mins)  stacked in dss with darks, flats and bias. It's only processed in dss with some curves in paint.net. Taken on the 130pds/AVX and modded 1100d. It's cropped just to make the target look bigger :) I seem to have lost the central star in processing...

post-33532-0-25529500-1432221160_thumb.p

Edit: Having just read Olly's comments, here's a greeny blue version :grin:

post-33532-0-01112300-1432222121_thumb.p

Louise

Edited by Thalestris24
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I think it's quite interesting that there's clearly a fairly intense "bar" across the middle of the PN that appears to extend into the outer shell.  I shall have to go and do some research to find out if this is actually thought to be a specific feature or just a random pattern.

James

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I managed 20 subs of M51 last night with the RASA & Atik 490 OSC but the weather has been really unkind. I only got 1 hour of cloud free sky....& when I went to work this morning.....not a cloud in sight..........makes me sulk.

Wow Rasa In action,

Im pretty curious to C what comes out of RASA in Combination with Atik 490. Saw one last weekend at a star party parked. looks huge, Is it difficult to handle ?

Cs

Rush

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i have started to get some of the outer shell of M27 and M57  and i have a white street nearly over the top of my Shedservatory, and 4 others surrounding my garden and i live at  the south end of a large town (thankfully not in the middle) but LP is still quite bad.

i do get severe gradients due to the LP even with oiii and lrgb but not with HA so there is hope no matter where you live.

Bloomin 'eck! - that light's a bit close. I'd have chosen another hobby by now.

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Bloomin 'eck! - that light's a bit close. I'd have chosen another hobby by now.

ahh but have you noticed that some one has splashed black paint over the back part of the street light ???

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Fantastic pictures. On the subject of green according to the site where I downloaded HLVG it states that there are no green astronomical objects- green is seen as noise pollution & should be removed. I'm not sure how true this is as I like green- just not as a cast all over my M13 picture!

There are some green astronomical objects, notably Wolf-Rayet planetaries, but they are very exceptional. Thor's Helmet will show as green in a good LRGB image. But n general green is indeed the root of all evil in colour balancing!

Most of us have seen the traditional out of the box M27 picture. I'm interested in capturing the faint outer shells & indeed some of you in these pictures have successfully captured this.

Now for my challenge & I really don't know if it is possible from my light polluted location is to capture the faint outer shells of the nebula. I have a fast astrograph. I'm not sure if the faint shell is RGB or narrow band data- let me know those who have captured it. I have a filter slide for the RASA with fast Baader narrow band filters good down to F2. This forces me to go with my Atik 460 mono camera (heaven forbid) I could try, when the sky gets darker, sets of 50-100 subs in each narrow band filter. I'm not sure if standard LRGB filters will behave at F2.2 but I can give them a try as well to obtain the full spectrum of data.

The RASA is also fitted with the official "cost an arm & leg" Celestron Astrodon light pollution filter but I still get heavy gradients which can be removed but it's another pain that might get better when the sky gets darker.

Keep your pictures coming. My mount is having a stability upgrade in the next few days. I'm going for Parallax rings mounted to the versa plate. I've just installed a sky watcher 80 mm refractor to use as a guide scope and this has the Lodestar X2 firmly screwed to the end with a C-mount adapter (must better than using the X2 in an eyepiece holder)

In principle the outer shells should eventually show in broadband because, after all, they do exist. The problem is one of contrast. Broadband filters hold down the LP and skyglow hard enough for the desired signal to rise above them. In the image I did with Yves there was little to show of the outer shells in broadband but we didn't bust a gut trying to get them in LRGB because we knew we could do so in Ha and O111 more efficiently. In a nutshell the RASA will pull in lots of outer shell but it will also pull in lots of skyglow to match. Think of an NB filter as a kind of crowbar to prise the signal away from the skyglow.

Olly

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Heres mine from last year, begging for a re-process! No narrowband for me so the outer halo remains hidden. And to give my opinion on the colour of the nebula, i lean towards blue/turquoise also.

15320723871_f1cc215b3c_b.jpg

Exposure:

48* 300sec, ISO 800, 805mm, darks, bias
Scope: Altair Astro 115EDT
Camera: Canon 600Da
Mount: NEQ6
Callum
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Wow Rasa In action,

Im pretty curious to C what comes out of RASA in Combination with Atik 490. Saw one last weekend at a star party parked. looks huge, Is it difficult to handle ?

Cs

Rush

This is what I got in 1 hour (20 x 180 sec subs). The conditions were frightful. Lots of low cloud. I can't wait for a nice clear night free of clouds, meteors, aircraft, neighbors lights, party next door......etc!. The RASA is easier to balance in DEC but I'm leaning to feel that it is harder to handle than the C11 as it puts greater demands on the mount. I still need to guide on exposures greater than 60 seconds because of the small Atik 490 pixels. I don't think the 490 OSC is that sensitive. Takes a long time to register decent colour.

post-36426-0-72460200-1432244937_thumb.p

Edited by pyrasanth
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ahh but have you noticed that some one has splashed black paint over the back part of the street light ???

My wife's like that when she's decorating, too.  Paint all over the place.  You'd never believe it.

James

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FWIW here's my M27 from data gathered over a lot of nights in April. It's 3 x 600s, 14 x 480s, 9 x 360s, 6 x 180s (3hrs 34mins)  stacked in dss with darks, flats and bias. It's only processed in dss with some curves in paint.net. Taken on the 130pds/AVX and modded 1100d. It's cropped just to make the target look bigger :) I seem to have lost the central star in processing...

attachicon.gifDumbbell_dssonly_pn_33pcCropAdj.png

Edit: Having just read Olly's comments, here's a greeny blue version :grin:

attachicon.gifDumbbell_dssonly_pnGB.png

Louise

Just wondering why many of my stars are so much redder than anyone else's?? This seems to be systemic in that all my images tend to show lots of red stars. There must be a simple explanation! Any hints or tips gratefully received!

Edit: Forgot to mention these were taken with a cls-ccd clip filter but I aligned the rgb in dss. Might it be something to do with the 1100d having a full-spectrum mod? The cls-ccd should cut the infra red.

Cheers

Louise

Edited by Thalestris24
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Been absent from SGL the past few weeks but when I stumbled on this thread couldn’t resist posting a couple pics created from data obtained last Tues. night. This was my first go at M27 and although both images exhibit what I’m guessing are processing artifacts (tiny red & blue dashes across the frame) I’m pleased considering I didn’t get any darks, flats or bias and ran out of time before getting as many red & blue subs as green.

So a few questions for the experts - Apparently it’s possible to revisit an object on a different night but what special challenges might that entail? Is it true calibration frames can be created after the fact and if so – which type(s)? Are these artifacts more likely due to the lack of calibration frames or post processing?

Guided 8” SCT w/focal reducer (1280 mm) - Luminance: 145 x 10, Red: 300 x 2, Green 300 x 8, Blue: 300 x 2. Backed off exposure time on luminance subs since brighter stars were noticably more “bloated” at 300 seconds.

post-37916-0-24395500-1432257564.jpg

post-37916-0-32889500-1432257576.jpg

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This is what I got in 1 hour (20 x 180 sec subs). The conditions were frightful. Lots of low cloud. I can't wait for a nice clear night free of clouds, meteors, aircraft, neighbors lights, party next door......etc!. The RASA is easier to balance in DEC but I'm leaning to feel that it is harder to handle than the C11 as it puts greater demands on the mount. I still need to guide on exposures greater than 60 seconds because of the small Atik 490 pixels. I don't think the 490 OSC is that sensitive. Takes a long time to register decent colour.

attachicon.gifM57-RASA3-CROP.png

Hmmmmmmmm,Yes, U need 2 guide, Focus isnt spot on I guess. For its monster light eating capacity, ought to show more details 4 that time span. Sensitivty, bInned or not ? Dont have any experience with 490m.

Took a shot for around 1,5 hrs with a 420 m.This is what i got from a Baby Tak. gd luck :) and

soon sky, cloud, weather miseries will pass on by and stars will shine for U all out there,

CS.

Rush

post-39070-0-23714200-1432286064.jpgpost-39070-0-00705000-1432286085.jpg

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Hmmmmmmmm,Yes, U need 2 guide, Focus isnt spot on I guess. For its monster light eating capacity, ought to show more details 4 that time span. Sensitivty, bInned or not ? Dont have any experience with 490m.

Took a shot for around 1,5 hrs with a 420 m.This is what i got from a Baby Tak. gd luck :) and

soon sky, cloud, weather miseries will pass on by and stars will shine for U all out there,

CS.

Rush

attachicon.gifM 51 C Kopie.jpgattachicon.gifM 51 jpeg Kopie.jpg

The conditions were awful for these exposures. I was shooting through very thin cloud so detail would be lost. Focus is an issue. I need to look again at the focus profile in focusmax as it does not like the 1x1 binning on the Atik 490 OSC. Perhaps it needs dimmer stars to focus on. I'm not too concerned- its more of a honeymoon calibration time with the RASA. I can work through all the problems ready for late July/August when the skies are darker.

The Atik 490 OSC is a bit of an insensitive colour beast at 1x1 binning (which is required for the Beyer to work!). I've never been particularly happy with the low colour saturation under less than ideal conditions. I've seen fantastic results with this camera but the shots seem to have been taken in the deserts of some unheard of country- certainly not 4 miles from Birmingham Airport!

I've started to step my toes into the Pixinsight software, man that is a culture shock from Photoshop! but I will persevere & get some training tutorials.

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Still has the unknown red/blue artifacts and obviously I completely missed the outer shell - but sure is fun to play around in PS to see how different representations can be produced from the exact same data...   :)

post-37916-0-30415600-1432307761.jpg

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  • 3 weeks later...

My first attempt at doing an image in just Narrow band, and although I have got some nice colours, all of the stars look horrible, so a lot still to learn processing wise.  All from last night, so not much data to play with (10 x 3 minutes 2x2 binned Ha, Sii and Oiii).  Ha treated as Red, Sii as Green, Oiii as Blue; flats & bias applied and all processing in PI.  Might try for some luminance if I get a chance tonight, maybe this will improve things :confused:

RHaGSiBOiiiFinal_zpsf8y9vnca.jpg

Edited by davedownsouth
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