IC1396 narrowband

[alexbb]

Hello,

I've been trying lately to acquire some data on the Elephant's trunk nebula area. I managed 2-3 hours one week ago on Ha on more than one night, after 4AM. Pretty tough the following days at work. As it was more a test for the next months when it will get high enough at reasonable hours, the subs were binned and I also wanted to shoot S2 and O3 just too see what's out there. I did this this morning, but there seems to be much less S and O emitting compared to H.

Bellow is the Ha image, the S2 and O3 are waiting to be processed, but I'm afraid I can't get anything usable just from 1h each. I'll share them later.

Could anyone also maybe share their processed channels separately? I can only find the Ha as mono on the internet.

My Ha details: ASI1600MMC, -15C, bin 2x2, Canon 300 F4 L, Optolong 7nm Ha filter, a bit over 2 1/2 hours in 180s subs, 300 gain.

Tiff link: https://drive.google.com/open?id=0ByhJ_xuQxcnjcjJBR1RhWWpmNlU

Thanks and clear skies,

Alex

[alexbb]

I managed to get 1 1/2 more hours of O3 and below are my processed results. O3 - 2 1/2 hours, S2 - 1 hour. Ha is above.

I also tried to create a HOO colour version which I also combined (very low percent) with a SHO combination (which looks embarrassing and I won't post it).

I'll also share links to the .fit stacked files if anyone wants to play with my data.

Ha: https://drive.google.com/open?id=0ByhJ_xuQxcnjUm4wQkhDOGpUTDA
Ha without darks: https://drive.google.com/open?id=0ByhJ_xuQxcnjNWtQWHpwemVzbjA
O3: https://drive.google.com/open?id=0ByhJ_xuQxcnjWDNHODIzWWV3VEU
S2: https://drive.google.com/open?id=0ByhJ_xuQxcnjVWFHaEwzZmhua1E

And the question in the post above still remains. Does anyone want to share some of their narrowband images of this target? I still can't find anything besides Ha.

Comments and critics are welcomed, though I know I have very limited data and I didn't put my best in processing.

Thanks for looking,

Alex

[alexbb]

Talking to myself again seems to.

Anyway, I restarted the project at full resolution and this time I went and I will go for longer subs, lower gain and longer total integration time. I plan ~10 hours for each channel, F/4 would gather some photons. Ha was shot during 5 nights for a total of 120x5 minutes. Unity gain (139), cooled to -15C. All calibration files too. Conditions were very good lately, though it was pretty low in the sky. During the night I shot above 25-30 degrees in altitude until 10-15 minutes past the astronomical sunrise. Don't have time to waste since I want to image other targets soon and they are visible at about the same time from my balcony.

I did a quick process this morning while I started shooting O3. The Canon lens doesn't seem to have the colimation spot on, but it's better than the Tair. I have elongated stars in the bottom-left corner and also in the top-right the stars seem to be bloated. I don't know if I can adjust anything to this setup so I think I have to accept it as it is until I get a proper scope. Stars in center look good though.

Don't mind the band at the bottom, it's a stacking artifact. I should have cropped it more, but I'll remove it when I will combine all the channels. I will also try to repair the elongated stars when I will have the O3 and S2. No star reduction and weak noise reduction.

Processing done in StarTools 3 times, one without additional contrast, one with some contrast applied and one with a low stretch just for the stars. I then combined all the 3 in GIMP.

Should I make it brighter?

Comments and critics are welcomed.

Clear skies,

Alex

[MattJenko]

Processing is as much art as science and is down to personal taste in the end, especially given the nature of narrowband imaging. I find that Ha, and Oiii can make decent HST pallette images with a synthetic 3rd channel. I would definitely experiment with a brighter end result, as you have some good data there and the moody look tends to hide the fainter detail you have fought hard to capture.

[alexbb]

Would this look better?

[MattJenko]

That one has more contrast between the features within the nebula and as a result makes it more interesting and I much prefer it, speaking personally.

[Knight of Clear Skies]

Good detail there. I'm a little on the fence about which of the two versions I like best, possible I'd prefer something between the two. 

[alexbb]

11 minutes ago, MattJenko said:

That one has more contrast between the features within the nebula and as a result makes it more interesting and I much prefer it, speaking personally.

Thank you for your feedback!

I'm shooting these days the O3 and I think that I'll aim for 8h for O3 and 3h for S2 before the clouds will cover the sky next Tuesday (also the moon will start to interfere too starting with Tuesday, just in case the clouds will stay away).

I'll add more when sky clears out and the moon goes away.

I think I'll try a R - 80% Ha + 20% S2, G - O3 and B - 85% O3 + 15% Ha approach, found here:

Regards and clear skies,

Alex

[alexbb]

2 minutes ago, Knight of Clear Skies said:

Good detail there. I'm a little on the fence about which of the two versions I like best, possible I'd prefer something between the two. 

Thanks! I think I'll try to brighten it more, it seems too dark on this screen. Last night it looked bright enough on my laptop, but I might try to connect during the weekend the laptop to the IPS monitor that I bought more than an year ago and I used maybe twice since then. Too many clothes on the chair though..

[alexbb]

Managed to acquire 2 more hours of O3 and I have now 6h of O3. I'm switching to S2 for the next 2 nights to get ~6h of S2 too and I'll get back to O3 and S2 when it clears again and the moon goes away.

The result of L - 80% Ha + 20% O3, R - Ha, G - O3, B - 80% O3 + 20% Ha:

Critics and comments welcomed.

Clear skies too,

Alex

[geordie85]

Very nice image. Stars are looking a little green though. Do you have HSVG? (I think that's the acronym) 

[alexbb]

40 minutes ago, geordie85 said:

Very nice image. Stars are looking a little green though. Do you have HSVG? (I think that's the acronym) 

Thanks! No, I have only GIMP and StarTools. I'll try to balance the colours better after I'll have the S2 channel too.

[alexbb]

This is the first try with almost 3h of S2. Tonight I will add 3 more hours and then cloudy nights for a while.

L: 70%Ha + 15%S2 + 15%O3

RGB: some combination. I tried R as Ha + S2, G as O3 and just a bit of Ha and B as O3 and some Ha. But in GIMP I mixed the colours until the stars looked somehow balanced and then I blended the result with another mix done in StarTools. I'll try better after this night of S2.

[sheeprug]

I'm not an imager, so i cant offer any practical advice, but thanks for the pics - very very impressive! 

SR.

[alexbb]

21 hours ago, sheeprug said:

I'm not an imager, so i cant offer any practical advice, but thanks for the pics - very very impressive! 

SR.

Thank you and clear skies!

Alex