Jellyfish Nebula - IC 443

[AbsolutelyN]

Last night was unexpectedly clear after about 11pm here. I decided to have a try at the Jellyfish Nebular but only had about 2 hours before if vanished behind the house. This is 85min of HA and just 6 mins each of G and B with 1600mm. Will try multi night exposures once more familiar with everything. The HA (ZWO version II filter) unfortunately has a big halo and it also has lensing which I've tried to minimise as best I can. Fascinating finding these objects for first time, never ceases to amaze how big many of them are in the sky. Wishing Skywatcher would produce a reducer for the Esprit 100 for wider field of view. 

Second version with flare better corrected in PS.

 

[Pig]

Excellent image.... very well done ?

[astro mick]

Lovely.

Mick.

[tooth_dr]

Amazing for such short integration time. 

[x6gas]

That's really nice.

I like how you have rendered Propus.  I recall that when I processed this target I spent a lot of time wrestling it into submission but looking back a few year's later I think it's too understated in my version so I very much like what you've done here especially with minimal RGB data and the issues you're having with your Ha filter.

BTW, the Sharpless catalogue is a good source of Ha targets in case you're not familiar with it...

[teoria_del_big_bang]

Great Image.

Yes last night surprised me as well with the clear skies up  north. I did look at clearoutside.com and it said 100% cloud cover till Midnight then 1% and then 0% but at 11:00pm looking outside at the rain though better of setting up and went to bed. Then at just after midnight got up to let an annoying cat out and couldn't believe how clear it was.

Unfortunately I was then in sleep mode and with work beckoning at 6:00 am though better of getting scope out and went back to bed. I must get on with an obsy then I can spend a quick hour getting some data easily.

Anyway glad you got some time to enjoy the clear sky, and once again a great image 

Steve

[vlaiv]

25 minutes ago, AbsolutelyN said:

Wishing Skywatcher would produce a reducer for the Esprit 100 for wider field of view.

https://www.teleskop-express.de/shop/product_info.php/info/p5125_APM-Riccardi-APO-Reducer-and-Corrector-0-75x---M82-connection.html

Here is mention of it being used together:

http://photonenfangen.de/instruments/skywatcher-esprit-100-ed/

[AbsolutelyN]

x6gas - I've never heard of the Sharpless catalogue - will have a good look at that thanks. Fantastic images on your website by the way.
vlaiv - The reducer looks very interesting, never seen that before. I think configuring something like that is probably beyond me (and budget) at the moment (still learning how to control everything) but certainly one to look at in future thanks. I think a better HA filter may be required first.
teoria_del_big_bang - Clear outside said it would cloud over at 3am for me so set a timer to cover scope but it stayed clear pretty much all night, turned out well after a disappointingly cloudy evening.  

Thanks for all the comments and feedback. Does anyone know why PHD2 only shows pixels rather than arc seconds in history graph? Option for arc seconds is greyed out and can't figure out how to enable it. 
 

[x6gas]

26 minutes ago, AbsolutelyN said:

Thanks for all the comments and feedback. Does anyone know why PHD2 only shows pixels rather than arc seconds in history graph? Option for arc seconds is greyed out and can't figure out how to enable it. 
 

You need to set the focal length of your guide scope and the pixel size of the guide camera and then it should report arc seconds... IIRC!

[AbsolutelyN]

3 minutes ago, x6gas said:

You need to set the focal length of your guide scope and the pixel size of the guide camera and then it should report arc seconds... IIRC!

Brilliant thank you! I'm sure that was set initially but must have somehow lost it. The guiding doesn't look as good now ... gone from 0.2 pixels to 1.2"! 

[codeman]

very nice image

[Anne S]

I did the Jellyfish last week using narrowband. It's a lovely object. Propus caused problems with my 15 minute subs, it was bad in all of them. I was using Baader filters. I haven't found our how to deal with it in Pixinsight yet, I resorted to gently cloning with a star mask in place to take down the outer sections.

i think it's most inconsiderate to have such bright stars right next to nice nebulae!

[AbsolutelyN]

3 minutes ago, Anne S said:

I did the Jellyfish last week using narrowband. It's a lovely object. Propus caused problems with my 15 minute subs, it was bad in all of them. I was using Baader filters. I haven't found our how to deal with it in Pixinsight yet, I resorted to gently cloning with a star mask in place to take down the outer sections.

i think it's most inconsiderate to have such bright stars right next to nice nebulae!

Hi Anne. What kind of problems did Propus cause? I'm considering Baader narrowband as they seem reasonable price, did you get any flaring cased by the filter?  

[Anne S]

All three filters flare. I was quite surprised as I only expected the O3 to have an issue. I've read online that this particular bandwidth can have problems. I've had the filters quite a few years.

edit: I've just worked out I bought them late 2010.

[AbsolutelyN]

Thanks Anne.  I may rule out Baader if they are likely to have same issues. Saying that it's possible to correct in processing to some extent. A bit of masking in photoshop and you can even out the tones reasonably well with curves. 

[x6gas]

1 hour ago, AbsolutelyN said:

Thanks Anne.  I may rule out Baader if they are likely to have same issues. Saying that it's possible to correct in processing to some extent. A bit of masking in photoshop and you can even out the tones reasonably well with curves. 

You can get some odd impacts on certain combinations.  Years ago I had an issue with really bad flaring using my FSQ85, Baader 2" filters and Atik 460.  I never had an issue with the Baader filters on my other scopes and others had reported no problems with the same set-up as me...  I wanted to upgrade to Astrodons and when I did the problem obviously went away... but it was all very curious.

[Demonperformer]

Despite the halo, that is a very nice image. 

[AbsolutelyN]

Thanks, that's interesting. I'm starting to get the impression it may be worth paying more and very slowly upgrading to Adstrodons over time, at least for one or two filters. So far only seems to be the HA filter I've had issues with but I've not imaged much to know yet. Thanks for the info.     

[x6gas]

1 hour ago, AbsolutelyN said:

Thanks, that's interesting. I'm starting to get the impression it may be worth paying more and very slowly upgrading to Adstrodons over time, at least for one or two filters. So far only seems to be the HA filter I've had issues with but I've not imaged much to know yet. Thanks for the info.     

Just bear in mind that if you are using different filters there will be a greater need for refocusing.  The Astrodons are parfocal within my typical seeing limits but obviously different combinations of makes can lead to a requirement to refocus which - depending on your data acquisition workflow can me more or less of a pain! 

[AbsolutelyN]

That's a very good point easily overlooked. Seems to be no easy (or cheap) solution! Maybe best to stick with Photoshop to clean things up ?

[ollypenrice]

Working in Photoshop it is very easy to eliminate Ha halos which are set against background sky rather than nebulosity. You simply don't apply them to the red layer.

For the integration time I think this is a sensational result. OIII adds a fascinating outer shell if you get the chance.

Olly