North America & Pelican Nebulas, HaO3 and Hubble Colours

[rich_t]

Hi,

It's been ages since I managed to get an image together but with a few clear nights on the trot managed to get O3 and S2 (approx 3hours 20 each) to add to my earlier Ha data of the NAN and Pelican area.

I need to read up some more on the hubble method as it was a bit of a struggle, ended up using Ha as Luminance which is not the best way to go I believe.

Images were taken with a Canon 200mm telephoto lens at F2.8,Atik 383 camera and Baader filters.

Thanks for looking.

Cheers,

Rich.

[ollypenrice]

Delightful images. I particularly like the first one because it approximates well to an RGB image but has the tiny narrowband stars. If you use Photoshop I think Noel's Actions plugin in (enchance local contrast) would really make this one sing.

Olly

[Rossco72]

The Ha Image is very pleasing indeed, not so sure I like the ubble one, not that it's anything technical, just somehow not so pleasing on the eye.

Thanks for sharing

Stuart

[Euan]

These are both excellent, great colours and razor sharp

I really like comparing targets in different versions, how did you make the top version did you use any RGB or is just a different combination of the narrowband?

At F2.8 I take it you are using 2" filters?

[rich_t]

Thanks for the comments.

I really like comparing targets in different versions, how did you make the top version did you use any RGB or is just a different combination of the narrowband?

At F2.8 I take it you are using 2" filters?

The top version was done by mapping the Ha to the red channel and the O3 to both the blue and green channels. I then just moved the colour sliders around a bit to try an make it as similar to RGB images as possible. Didn't use an RGB layer.

The filters used were 1.25". Seem to be able to get away with these because of the rear elements of the lens are 30mm in diameter and about 30mm inside the back of the lens. I thought that if the rear element was 30mm across and the chip diagonal was around 22mm, then the cone of light between these two would be around 26mm half way between them where the filter is, which fits through the filter. The filter is actually closer to the CCD than the lens I think so there should be a bit more margin than this.

Cheers,

Rich.

[adamsp123]

It is very interesting to see both of these excellent images together, I personally really like the "hubble" version I see more detail all be it in strange colours.