M42 with C9.25 and Pentax *ist DS

[Dennis]

Hi

Here is an image of M42 from last night, the first time I have used the Pentax *ist DS DSLR on the C9.25 at prime focus (F10). Taken from the suburban skies of Brisbane.

The “wide” image is the full field resampled from 3000x2000 to 1024x684. The “close up” is a simple crop from the centre of the full frame to show the region around the Trapezium.

C9.25 at F10, Pentax *ist DS DSLR, 400ASA, 50 x 30 sec exposures captured using the Pentax Remote Assistant software. Final image aligned and combined with ImagesPlus. The image was auto guided using a WO 80mm f7 refractor and Orion Star Shoot Deep Space ccd camera using the Shoestring USB adapter.

Cheers

Dennis

[matt]

Beautiful Dennis

Such fine work with so many different cameras and scopes.

Awesome!

[atalas]

Nice core detail Dennis.

[Striker (Tony)]

Well done Dennis.

You have done well to get the trapezium well defined.

Just what I like to see..someone else imaging at a long focal length.....I dont feel so alone now.

[spearo (Frank)]

Go the C9.25 !
well done!

frank

[iceman (Mike)]

Now all you need is a canon camera, Dennis! Great stuff.

[h0ughy (David)]

dennis I take it you were only after the trap? Very nice. can you go longer, be interesting to see what the pentax can do when pushed?

[Dennis]

Hi Dave

I was just playing around with the following (for me) new techniques:

• Auto guiding using the Orion Deep Space Star Shooter (the model with Thermo Electric Cooling).
• Using the Shoestring USB and Takahashi adapter.
• Using PHD guiding from Stark Labs
• Using a separate guide scope.
• Using the Pentax *ist DS on the C9.25.
• Focusing the Pentax using the Stiletto focuser.
• Imaging at F10 prime focus.
• Setting up the Meade 647 flip mirror unit.
• Using a single notebook computer for acquiring images via the Pentax, guiding via the Orion Deep Space Star Shooter and performing GoTo’s via SkyTools.

Anyhow, there are some severe limitations with the Pentax as follows:

To confirm best focus, I had to grab 1 sec exposures, download the image, use the proprietary Pentax Photo Browser software to inspect the image, tweak the focus, download the next image etc until I could confirm sharp focus. The Stiletto seemed to do this okay, but I had a play around with the Pentax Remote Assistant software just to confirm focus.

Next, using the Pentax Remote Assistant software, you can only automate interval shooting at 30 secs max, in Manual mode. If you switch to Bulb mode, you can only execute single exposures by manually holding the shutter release – you cannot program a single 3 min exposure, let alone several.

Every time the Pentax took a 30 sec image, it also automatically took a 30 sec dark frame. It does not appear to store and re-use this dark frame, so each 30 sec exposure lasts 60 secs plus 10 secs for processing/download.

ImagesPlus supports Canon and Nikon but not Pentax.

Cheers

Dennis