Orpington Astronomical Society

Astronomy => Astrophotography => Topic started by: RobertM on May 20, 2008, 21:29:58

Title: Markarians Chain - Deep Sky Challenge
Post by: RobertM on May 20, 2008, 21:29:58
Well it the last day to post something in the challenge before the next meeting so luckily I managed to stay up and catch this: http://gallery.orpington-astronomy.org.uk/displayimage-474.html (http://gallery.orpington-astronomy.org.uk/displayimage-474.html)

Conditions were pretty bad for faint objects and I should have called it a day after the first sub - I'd really like to do this one again in dark skies.  Yes I know I missed off most of NGC4477 to the top left but you can just see the edge if that counts...

Not a patch on Marks excellent image but I think it's half reasonable given the conditions none the less.

Title: Re: Markarians Chain - Deep Sky Challenge
Post by: JohnP on May 20, 2008, 22:01:12
That's pretty good Robert - Well done under such difficult conditions - Did you use a camera lens on the front of the H9..? John
Title: Re: Markarians Chain - Deep Sky Challenge
Post by: RobertM on May 21, 2008, 08:53:04
It was taken with the Sky 90 with F4.5 reducer corrector.  It really needs double the resolution to do the view some justice as image resolution was around 4 arc sec per pixel.  I've been resisting for a while but I need more pixels for this combination so maybe it's time for a DSLR or a bit of luck on the second hand market.
Title: Re: Markarians Chain - Deep Sky Challenge
Post by: JohnP on May 21, 2008, 09:47:04
oherrrr...!!! Pixel Fever... Quick get an antidote or a bank loan....... :lol: John
Title: Re: Markarians Chain - Deep Sky Challenge
Post by: Mike on May 21, 2008, 10:41:08
Nice image Robert. You've done well to go so deep in these crappy skies and the warm weather.
Title: Re: Markarians Chain - Deep Sky Challenge
Post by: Mike on May 21, 2008, 16:42:33
How about one of these........

http://www.engadget.com/2008/05/21/canons-rebel-xs-1000d-specs-uncovered/
Title: Re: Markarians Chain - Deep Sky Challenge
Post by: MarkS on May 21, 2008, 17:45:05

If you're thinking of trying second hand be aware that the Canon EOS 300D is extremely slow to write a RAW image to the memory card (approx 7sec) and also has a relatively high read noise (12e/pixel).

I'm seriously considering upgrading to a Canon EOS 350D - it is much faster to write RAW images and the read noise is much reduced (7e/pixel) - it also has 8 Mpixels instead of 6 Mpixels.

In general be wary about a high number of Mpixels - the more you have, the fewer photons hit each one and then the lower the signal/noise ratio.

The EOS 350D outperforms the later 400D (for astrophotography):
http://astrosurf.com/buil/400d/400d.htm
Title: Re: Markarians Chain - Deep Sky Challenge
Post by: Fay on May 21, 2008, 18:39:43
That is good, Robert, that Moon was very close to that area. I was poised to do it myself, but was not sure if I had the best area on the chip, which is smaller than yours.