ukastronomy wrote:
Big Images from Small Telescopes (2)

IC 1805 a bright nebula in Cassiopeia

IC1805 is unusual in that even the usually mega reliable SkyMap Pro
doesn't really give a good impression of what the nebula will look
like though a telescope. Indeed the first time I imaged IC 1805 I had
to double check that I had not mis-identified the object. IC1805 was
both larger and more complex than I had imagined.

The image was created by median combining 6 x 300 second images taken
with a Takahashi Sky 90 with SBIG ST-10MXE and a Hydrogen Alpha
filter.

http://www.martin-nicholson.info/ic1805/ic1805.htm


Hi Martin,

Nice Image! But I think the back point might be a bit too low which will
hide some of the original data.

Also while the ST10 has a much higher quantum efficiency than the STL I
still think 5 min subs are too short. That leaves you having to stack
beacoup more images to get the same depth. At f/5 I use 30 minute subs
in H-Alpha from a light polluted location and go 45 minutes at f/6.


Here is my version taken with an FSQ and STL (18x30 minutes)

http://www.celestial-images.com/Imag...x1800s-Ha.html

Regards

Bill