Last night was my first attempt with my recently acquired C11 with Hyperstar 3 and (Chris sit down safely before you read this) a Starlight Xpress SXVF-M25C cooled colour camera.
Just about everything went wrong but I'll present some initial results anyway.
Firstly I'll get the excuses out of the way:
1) My polar alignment was out. I now realise this was because there was a mole hill that has appeared next to one of the three carefully leveled bricks in the soil where I place my tripod - I'm honestly not making this up!
2) Then I somehow selected a guide star well outside the area being imaged. The combination of these 2 problems meant all the stars are elongated by different amounts depending on their position in the frame.
You can see this in the raw sum of the dithered subs:
(http://www.markshelley.co.uk/Astronomy/2013/hyper_raw_sum.jpg)
The guide star was off to the left somewhere.
3) I had to perform manual dithering because the USB hub on my laptop is not powered and couldn't cope with the power requirements of an imaging camera and guide camera - so I used a different laptop for each!
4) I forgot to use an IR filter so all the stars are bloated. It's probably also the cause of the weird mis-shaped stars near the corners and the fact that the colour balance has been ruined - everything appeared very very blue.
This image is a cropped and scaled version from 20 x 5 minute subs all at F/2:
(http://www.markshelley.co.uk/Astronomy/2013/hyper_m81_cropped_scaled.jpg)
The full size version is here:
http://www.markshelley.co.uk/Astronomy/2013/hyper_m81.jpg
And here is a comparison with 18x5 minute subs using the Canon 350D on the F/2.8 Takahashi Epsilon "Bananascope":
Bananascope on the left and Hyperstar on the right.
(http://www.markshelley.co.uk/Astronomy/2013/m81_comparison.jpg)
It's not a fair comparison in terms of resolution because of the "bloat" problem but it might give some idea of the amount of faint detail that can be extracted.
The upshot of all this is that I'll have to repeat this test and do it all properly next time we get a clear sky (if ever).
Mark
Quote from: MarkS on Mar 05, 2013, 23:40:32
Last night was my first attempt with my recently acquired C11 with Hyperstar 3 and (Chris sit down safely before you read this) a Starlight Xpress SXVF-M25C cooled colour camera.
Great capture ;)
I knew you would do it...
Nice one, the setup does show potential
Can you take it back now please so the clouds go away :(
Be interesting to see how you get on with this Mark.
Moles - ah yes, I remember that!!!!
Roll on the permanent Observatory.
Carole
Quote from: MarkS on Mar 05, 2013, 23:40:32
.....a Starlight Xpress SXVF-M25C cooled colour camera.
Wow!! :o You've really surprised me Mark getting that camera as I was convinced you were going to get another DSLR. I will be interested to see how your images compare with the Canon.
Quote from: Mike
Wow!! :o You've really surprised me Mark getting that camera as I was convinced you were going to get another DSLR. I will be interested to see how your images compare with the Canon.
I wanted to go down the Hyperstar route because I think F/2 optics will be ideal for my sky conditions but the Hyperstar really needs a cylindrical bodied camera. Moreover a DSLR is not ideal for Hyperstar imaging because the sensor ends up with severe vignetting because it sits at the back of a rectangular "tunnel".
But I have also just bought a Canon 550D off eBay (they're selling for under £300 now) which I will mod and use on the other scope(s). So if I wreck it I haven't lost much. It will be very interesting to compare it directly with my current Canon 350D "workhorse" and with the SX.
Mark
Quote from: mickw on Mar 06, 2013, 08:23:32
Can you take it back now please so the clouds go away :(
That won't make a difference, intra society transfers don't count (or rather they are cloud neutral) :)
Robert
It will have a good home! (Once the observatory is approved)
Nice one Mark & no Spikes.... I feel the image is not complete though - Any chance you can add some I've heard that some guy called Noel Carboni makes a really nice plug in for photoshop ;-)
Seriously good start though...
John