NGC7793: First light with plane wave CDK

[Geoff45 (Geoff)]

This was first light for my 12.5" Plane Wave CDK telescope. I was impressed by the way the AP900 handled the beast--sub arc second guiding.
I am reasonably pleased with the way the galaxy turned out, but the background is a little suspect--probably because I didn't take flats. Still working on a method of taking dome flats. Lots of little background galaxies to see.

Anyway, here is a link to the image:
http://www.astrobin.com/63012/

Exposure: R:G:B:L 70m:70m:70m:70m
Camera: QSI540wsg
Scope: Plane Wave 12.5" CDK
Mount: AP900
Acquisition: MaximDL
Processing: Pixinsight

Geoff

[Stevec35 (Steve)]

Looks very promising Geoff. The background does look slightly wonky but not too bad.

Cheers

Stev

[strongmanmike (Michael)]

That is one f***ing awesome image of this galaxy Geoff congratulations...Bah, that thin little straw of a refractor is a thing of the past Wow

Mike

[RobF (Rob)]

Certainly doesn't look like a half-hearted effort. Very natural processing and background. Looks like a sweet rig

[ChrisM]

A nice clean image Geoff, and as you said, lots of background galaxies visible. You gotta like the AP mounts!
Chris

[Spookyer (Brett)]

Good one Geoff, big things to come I bet with this setup

Brett

[RickS (Rick)]

Very nice, Geoff.

[gregbradley]

An excellent image Geoff. Your CDK looks like its running well and a good match with that camera.

Greg.

[Shiraz (Ray)]

that is a ripper image Geoff. darned hard target that looks like it was captured with ease - lovely restrained processing.

[SpaceNoob (Chris)]

Awesome image Geoff.

Mine arrived too, recently. I've done some testing but still waiting on some things so I can fit the full image train. The CDK is such a nice scope, looks like you are getting good results

One surprising thing I found was that my collimation was pretty much spot on.... after it was sent half way around the planet!

[Geoff45 (Geoff)]

Originally Posted by SpaceNoob

Awesome image Geoff.

Mine arrived too, recently. I've done some testing but still waiting on some things so I can fit the full image train. The CDK is such a nice scope, looks like you are getting good results

One surprising thing I found was that my collimation was pretty much spot on.... after it was sent half way around the planet!

Thanks Chris. I got mine second hand and it's had a few bumpy rides in the back of my car, but the collimation still seems pretty good.
Geoff

[gregbradley]

In my observatory during the day there is a small amount of light that filters in through the gap between the roof and the walls. This is handy as I use it to take flats quite successfully. I put the cotton cover my wife made over the end of the scope which is pointed to a neutral lighted area and then take flats. They seem to work well. Perhaps you can do that in your observatory.
I take just 3 of each filter and no dark subtract. I subtract a bias when I callibrate the image. I don't know about the CDK12 but the 17 vignettes a fair bit and tends to have a hot spot in the centre of the image so I have experimented with flats and this method was advised to me by Don Goldman of Astrodon and works best I am finding.

Greg.

[Geoff45 (Geoff)]

Thanks Greg
Will give it a go
Geoff

[gregbradley]

Originally Posted by ghsmith45

Thanks Greg
Will give it a go
Geoff

The key would be to have the scope pointed at neutral and even lighting or a dim area that is even.

Greg.