Narrowband Cygnus – again!

Staying with the Cygnus and narrowband theme, here’s last nights effort. This was taken on the Atik 314L+ through an old 50mm f/1.7 Pentax lens stopped down to f/2.8, and used 10 x 3min Ha, 11 x 3min OIII, but I only got 4 x 3min SII before the cloud rolled in. Processing for this was done in AstroArt and Photoshop.

Cygnus SII_Ha_OIII 

A Bicolour North America Nebula

Back to NGC7000, the North America nebula, this time with a Sigma 105mm f/2.8 lens. For this image, 10 x 5min images were captured through both H-alpha (used for the red channel) and OIII filters (for blue). The red and blue layers were then combined in the ratio 60:40 to make the green layer, and the R, G, and B were then assembled into the final image.

Wide angle photography

A while ago now I acquired a Geoptik adapter to fit Canon lenses directly to the Atik, the beauty of this adapter being that 1.25″ filters can be used with it. I was able to connect my 200mm Canon and 105mm Sigma lenses to it OK, but wider angle 50mm and 28mm lenses couldn’t be brought to focus. In my lens collection are a couple of old Pentax K bayonet lenses  – a 28mm f/2.8 and a 50mm f/1.7; I got a cheap Pentax K to Canon adapter, and last night tried these lenses out on the Atik. The 28mm wouldn’t focus, but the 50mm was fine 🙂

These are two quick images that I took. The first is a region of central Hercules which includes M13, just right of centre; it’s a stack of 6 x 2min exposures at f/4 through an Astronomik CLS filter. The second is of the region aroun the North America and Pelican nebulae, and is a stack of 10 x 2min exposures, binned 2×2, through a hydrogen alpha filter. Accurate focusing is a lttle tricky, but the results are good enough to persuade my to try further with this lens.


The Pelican Nebula

Because I have to put up with a certain amount of light pollution, I usually prefer to image with narrowband filters. One of the things a bout this time of year is that there aren’t too many suitable subjects around that I can see from my observatory. However, if I stay up late, I can now start to get a view of some of the great summer objects that are appearing in the sky again.

This shot of the Pelican Nebula (IC 5070) in Cygnus, taken with the ED80, is made up from just 6 x 5min each through Hα, OIII and SII filters.

More Cygnus

As we had another couple of hours of clear skies last night, I decided to capture dome more of the Cygnus region. The image below has combined the 15 exposures from Wednesday evening with another 20 from last night, and appears to have brought out a bit more detail in the areas of faint nebulosity, as expected. Total exposure time for this image is now 70 min at f2.8, ISO400.