Pelican AT8RC Bi-Color Narrowband

[Rudeviewer]

It has been some time since i posted here.  Weather has kept me from collecting any data for quite some time.  Anyways, Here is my process of the Pelican. This image consists of 9 HA and 10 OIII both 1200s Bin 1x, no flats, but bias and darks....Used a good narrowband tutorial to process this, but could still use some work.  when i sharpened a tad i got some dark halos.  I tried not to over-saturate since that's kinda my signature move lol.  Its still a little noisy but i can live with it for now. I got 10 images of OIII before the clouds rolled in, so i am happy just to get the data i did. 

Gear: Celestron CGEM DX, Atik 383l+, AT8RC, OAG wLodestar x2 sx filter wheel, Baader HA-OIII Filters.

[Rudeviewer]

Does anyone here use astrdon filters for doing narrowband?  I am considering getting a HA 5nm and a OIII 3nm for doing these types of images and was wondering what help it would be??

[gnomus]

I like it Rude.  More subs will usually help with the noise.  There's nothing obviously amiss in your image, but I would be reluctant to forego flats.  I find them very important.  

[Rudeviewer]

20 minutes ago, gnomus said:

I like it Rude.  More subs will usually help with the noise.  There's nothing obviously amiss in your image, but I would be reluctant to forego flats.  I find them very important.  

 

I totally agree with the flats.  I have no excuse other than i just didn't do them lol.  I added a skyglow filter to my image train and needed to redo them and just haven't made it around to it yet.....Now that you say that, I might use the bad upcoming weather to do the flats.

[swag72]

This looks good..... Its a most pleasing image.

3nm Astrodons...... Frankly the bandwidth is excellent for imaging far into the moons cycle, especially with the Ha filter. 

[Rudeviewer]

17 minutes ago, swag72 said:

This looks good..... Its a most pleasing image.

3nm Astrodons...... Frankly the bandwidth is excellent for imaging far into the moons cycle, especially with the Ha filter. 

Thank you for the comment Sara.  As for the astrodons, kinda seems like a no brainer huh......too bad they are so expensive.  Maybe one at a time.  

[gnomus]

The Astrodons are great, but a helluva price for a wee bit of glass.  Like me, you may feel a little ashamed to have spent that much on so little.  On the other hand, the results .....  

There is a bit of a debate as to whether you should go for the 3nm or 5nm filters.  Both are very good, and with the Ha there may be some benefit to having the 5nm.  Do a lot of research before buying, because it is a major outlay.

[Rudeviewer]

Very good point.  I believe they are the same price.  So i guess it comes down to the transmission lines and what SNR increases there will be with the different NM filters.

 

[gnomus]

I don't believe they are 

[Rudeviewer]

You are correct.  A much cheaper pricepoint now that i actually was looking at the 2 different ones....

650 for the 3nm as opposed to 435 for the 5nm.

[Rudeviewer]

This is where like Gnomus said research comes into play, I have a filter wheel that accepts 36mm unmounted.....and im only fiding 5nm in the unmounted filters......guess ill have to email and find out what is actually available. 

[gnomus]

Oh - you can get 3nm in unmounted 36mm too.  Please ensure that you are appropriately medicated before looking up the price.  Incidentally, you are fortunate in that they will be cheaper in Colorado than they will be over this side of the pond.

[Rudeviewer]

Yea i actually just checked them out on their website and they are available.  I think i will have to do one at a time for that cost.  It better place my images in a state of awe once purchased lol.

I don't mind my 7nm HA but the 8.5 for OIII and SII just don't cut it, there is too much extra stuff making it through and making it a tad difficult to process and have stars match up as good as i like.

[gnomus]

Don't want to blow my own trumpet, but there is a compaison of 5nm vs 3nm in this thread - https://stargazerslounge.com/topic/295500-pelican-in-ha-first-real-test-of-dual-rig/

[Rudeviewer]

Awesome!  Thanks for the post there.  I'll check it out.

[Rodd]

On ‎6‎/‎23‎/‎2017 at 11:45, Rudeviewer said:

Does anyone here use astrdon filters for doing narrowband?  I am considering getting a HA 5nm and a OIII 3nm for doing these types of images and was wondering what help it would be??

I use 3nm Astrodon NB filters.  They are awesome.  I chose to get all of them 3nm.  But I also have Baader NBs that came with the camera and I have the 7nm Ha installed as I have 8 positons on my filter wheel.  I have not yet done a comparison, but with the Astrodons I get no halos, and it seems easier for me to process the stars without magenta rims.  I would recommend them.  the literature indicates that while less % of light pass through the filter, there is a resultant higher signal to noise ratio. 

Rodd

[Rudeviewer]

3 hours ago, Rodd said:

I use 3nm Astrodon NB filters.  They are awesome.  I chose to get all of them 3nm.  But I also have Baader NBs that came with the camera and I have the 7nm Ha installed as I have 8 positons on my filter wheel.  I have not yet done a comparison, but with the Astrodons I get no halos, and it seems easier for me to process the stars without magenta rims.  I would recommend them.  the literature indicates that while less % of light pass through the filter, there is a resultant higher signal to noise ratio. 

Rodd

That is exactly what i thought about doing.  I like the smaller star sized and SNR of the 3nm.  Significant price increase but It seems to be well worth it.  I am fighting the magenta Halos all the time with my Baader ones at 7HA 8.5 OIII 8SII.  Its still something that is doable, but if i am going to buy filters i know now which ones to go with.  Thank you Rodd for sharing your experience.  

[PatrickGilliland]

Nice work - to my eyes a little bit of halo around some stars but nice work all round.

[Rudeviewer]

31 minutes ago, PatrickGilliland said:

Nice work - to my eyes a little bit of halo around some stars but nice work all round.

Thanks Paddy.  You are correct about the halos.  I am looking into different filters that should help me reduce halos around stars while imaging narrowband, but they are pretty expensive so it may take some time for that to happen.  In the meantime ill just have to try to keep the halos to a minimum.  

[Allinthehead]

Hi Rudeviewer. Nice image. I have the 5nm ha and the 3nm OIII. If i had the dosh i would've gone for the 3nm ha. Having said that i'm delighted with my 5nm.

[Rudeviewer]

20 hours ago, Allinthehead said:

Hi Rudeviewer. Nice image. I have the 5nm ha and the 3nm OIII. If i had the dosh i would've gone for the 3nm ha. Having said that i'm delighted with my 5nm.

Does the 5nm HA and the OIII have similar star sizes.  When i purchase the filters, i am hoping to reduce the halo effect.  I am sure i can do a better job in proccesing to keep the halos from showing, i just figured all the help i can get couldn't hurt.  

[DaveS]

With my small sensor CCD I could go with the 1.25" mounted so got the full set of four 3nm filters so I could look at the [NII] as well as the HII.

At the time they were "only" £385 each , now they're £490    .

With 4 filters you have more options, for instance you can go with HII on its own and put [NII] into another colour channel, or combine them into (H+N), as they would be with a wider filter.

[Allinthehead]

3 hours ago, Rudeviewer said:

Does the 5nm HA and the OIII have similar star sizes.  When i purchase the filters, i am hoping to reduce the halo effect.  I am sure i can do a better job in proccesing to keep the halos from showing, i just figured all the help i can get couldn't hurt.  

As far as i can tell from my total experience of 2 bicolor images stars are similar. Conditions on different nights are never the same so hard to tell.

[Rudeviewer]

2 hours ago, Allinthehead said:

As far as i can tell from my total experience of 2 bicolor images stars are similar. Conditions on different nights are never the same so hard to tell.

Thank you for sharing your experience with me.