IC 5070 Pelican Nebula in Ha with ASI100MM

[Guest]

It was such a warm night last night that the camera didn't get below -26c

Made it really pleasant to get the scope up and running though :-)

Here's my start on the Pelican Nebula in narrow band - the weather doesn't look promising for the coming week and before you know it it will be passed its prime location in the sky

This was 11 x 5min Ha with flats but no darks (I HAVE to get around to making a dark library lol)

Higher Res: http://www.wobsastro.com/ASI1600MM Gallery/#IC_5070_170828_115mm_ASI1600_11x5min_Ha.png

 

 

[Guest]

I subtracted the appropriate dark frames from this image and improved it a lot I think :-)

[wimvb]

Lovely image. Especially without the amp glow. 

[Guest]

16 minutes ago, wimvb said:

Lovely image. Especially without the amp glow. 

Yar - makes a bit of a difference LOL 

[Guest]

I took just 4x5min subs of Sii the other night before the camera just about hit the pier 

I've added these to the image above using Pixinsight PixelMath with Ha/Sii/Sii

It's turned out pleasingly red but I'm not sure it's supposed to. I would've expected the red with Oiii but shouldn't Sii give a brown cast?

Thanks for any advice

David

 

 

[wimvb]

Great colour image.

Final colour depends on the proportions between the channels. If you apply (not permanently) the same stf autostretch to all the images before combining them, you get a fairer impression of what the final image will look like. If you apply stf to each image individually, they will all show up equally bright, even if they're not. Another method is to read the pixelvalues of each channel and compare those.

[Guest]

33 minutes ago, wimvb said:

Great colour image.

Final colour depends on the proportions between the channels. If you apply (not permanently) the same stf autostretch to all the images before combining them, you get a fairer impression of what the final image will look like. If you apply stf to each image individually, they will all show up equally bright, even if they're not. Another method is to read the pixelvalues of each channel and compare those.

Thank you 

I had a look at them in stf before combining and they looked as they should (ie monochrome) 

As for the proportions of Ha, Sii, Sii in combining them I used 100% for each - when I used other variations (ie Sii 80% + Ha 20% etc) the image came out green or blue depending on the mix I used.

I got red with 100% in each channel with Ha, Sii, Sii so figured that must be ok? Still I expected to see brownish or blue accents instead of red.

Thanks again

David

 

[Merlin66]

Sii is so close to Ha it's a very similar red....

You mention OIII which is obviously blue/ green , but I don't see any.....

[wimvb]

For a mono camera such as the asi 1600mm, you will only get b/w images. When you put Ha in the red channel and Oiii in another, you will end up with a colour image. But if the Ha image is much stronger (read: brighter) than the Oiii, your image will come out red. Since your image has white stars, you do have colour in all three channels. But besides in the stars, the contribution from Oiii and Sii is much weaker. Try to make a colour image with only Oiii and Sii, and see what that looks like.

[Guest]

Thanks all - just to mention there isn't any Oiii in this image - I mention above that I was able to add Sii - I haven't been able to add any Oiii yet

I will try to created an Oiii/Sii image when I get some clear skies as suggested :-)

David

 

[wimvb]

2 minutes ago, David_L said:

Thanks all - just to mention there isn't any Oiii in this image - I mention above that I was able to add Sii - I haven't been able to add any Oiii yet

I will try to created an Oiii/Sii image when I get some clear skies as suggested :-)

David

 

Oops, my bad. But the idea is the same.