Three Galaxies and Keyhole

[alexch (Alex)]

Hi All,

The Monday night forecast looked good so I packed my camera gear and 22" Dob and went to my favourite spot in Flinders. After setting up the panning time-lapse Greg and I had a rather long observing session. The seeing was average so we stayed at low powers and the highlight of the night were a few galaxies near LMC (in Dorado and Volans).

The time lapse is here (23MB MP4)
Less bandwidth consuming but lower quality video is here on Vimeo

At the end of observing Greg (from MPAS) lent me his Pentax K-x, I put it into the focuser of my Dobsonian and took my first ever DSO image through the telescope. It was windy and my Dob astro-photography expectations were quite low, but I rather liked the result on the camera screen so kept going. Because of the wind I could only use two frames of the Keyhole nebula and the result is attached below.

Finally I feel my post in the Deep Space section is justified

Tech data below.

Timelapse
Nikon D700, 14-24mm lens, ISO 3200, 754 frames x 30sec
Orion Teletrack motorised mount for panning effect

Keyhole Nebula
Telescope: 22" f/3.6 reflector on Alt-Az Dobsonian mount with imaging Paracorr
Camera: Pentax K-x
Image: 2 x 6 second frames at ISO6400
Processing: DSS for stacking and Photoshop CS5 for levels, noise reduction and sharpening. The final frame is not cropped, just resized.

Cheers,
Alex

[Bassnut (Fred)]

Very excellent timelapse, very ordinary keyhole.

[alexch (Alex)]

Originally Posted by Bassnut

very ordinary keyhole.

Agree 100% with the above.

However taking the first time ever deep space image was quite an exciting bonus to the observing session. I did not expect to get anything remotely usable with 6-second short exposures on Alt-Az Dob mount. I was also surprised that the whole field of APS-C size sensor in Pentax K-x looks okay with Paracorr and will investigate de-rotating devices to allow longer exposure times.

Cheers,
Alex

[gregbradley]

That's a great time lapse. Welcome to the deep sky section!

Greg.

[Bassnut (Fred)]

Ive changed my mind, thats a very excellent keyhole for what.....2 off 6 sec exposures??, insane.

[irwjager (Ivo)]

That time lapse is awesome!

Yes, the Keyhole Neb is average compared to the gems we're being treated do on a regular basis here on IIS, but when you consider that's just 2x6s frames on a bog standard DSLR it becomes quite impressive. Who says you can't do DSOs with a dob!

[alexch (Alex)]

Originally Posted by Bassnut

Ive changed my mind, thats a very excellent keyhole for what.....2 off 6 sec exposures??, insane.

I was quite perplexed myself but I guess 22" of aperture helps shorten the exposure time.

Fred, I noticed a Pyxis de-rotator in your signature. Could you share how well does it work with LX200 and MOAG? I was thinking about either pyxis or this unit:
Orion SteadyStar Adaptive Optics Guider w/Rotator

Cheers,
Alex

[alexch (Alex)]

Originally Posted by gregbradley

That's a great time lapse. Welcome to the deep sky section!

Greg.

Originally Posted by irwjager

That time lapse is awesome!

Yes, the Keyhole Neb is average compared to the gems we're being treated do on a regular basis here on IIS, but when you consider that's just 2x6s frames on a bog standard DSLR it becomes quite impressive. Who says you can't do DSOs with a dob!

Greg, Ivo - thanks heaps!

[Bassnut (Fred)]

Originally Posted by alexch

I was quite perplexed myself but I guess 22" of aperture helps shorten the exposure time.

Fred, I noticed a Pyxis de-rotator in your signature. Could you share how well does it work with LX200 and MOAG? I was thinking about either pyxis or this unit:
Orion SteadyStar Adaptive Optics Guider w/Rotator

Cheers,
Alex

The pyxis works very well (both OTAs) and is very solid (3in version), it is however VERY noisy and VERY slow, but there aint many choices, I dont know the orion at all.