Monday, March 30, 2009

Secondary mirror problem.

Hmmm... I had a problem with my secondary mirror on my C9.25 last night.
I went to collimate and found that the whole secondary mirror assembly rotated!!
Oh my gawd!
This is not very good for collimating, because I know that the mirror has to be in a particular position in respect to everything else on the scope.
I posted a message onto the Cloudy Nights "Cats & Casses" asking for help, and got a reply back straight away from 'Uncle Rod Mollise' telling me how to take the corrector plate off to tighten the assembly. Thanks Rod.
Sleeping on it though I thought I'd have a go another way.
I thought that if I could pull on the assembly whilst turning it in a clockwise direction, it might just catch enough to tighten... and guess what? bingo! it worked.
All I had to do was make sure that the assembly was aligned correctly and I would be back in action. I just need to re-collimate ;-)

Here's a picture that I took a couple of years ago showing the correct orientation with respect to Bob's Knobs (NB. I think the indent positions pertain to my scope only, looking at pictures of other scopes, the positions vary):-

Corrector plate removal instructions. (In an emergency do not break glass)

1. The corrector must go back on in the same rotational orientation as before USUALLY the small, engraved serial number on the corrector goes to three o'clock. Maintain the original orientation of the secondary holder.

2. If there are shims present around the edge of the corrector, these must be replaced in their original positions--mark 'em.

3. When you are done, do not tighten the corrector retaining ring too tight--just finger tight.


Friday, March 27, 2009

Blast from the past - Clavius 20th Sept 2008

Going through some of my old files, I found this Clavius from last year that I've never processed.

New Moon 27th March 2009

Managed to capture this new Moon just before the clouds caught it.
85mm Canon EOS 400D, 400 ISO.

Thursday, March 26, 2009

Venus 18th March 2009

Here's one that was taken the other day, that I've only just got round to processing.
Probably the last Venus, this side of the Sun for this year.

Saturday, March 21, 2009

Saturn & Titan 20th March 2009.

Transparency wasn't very good tonight, so I thought I'd image Saturn and Titan at rather a high gain for the DMK, (because of the low light level).

Thursday, March 19, 2009

Saturn 18th March 2009.

Here's an animation of the storm on Saturn. This time it isn't a Moon.
The timestamp was 21:36 to 23:14 UT

Below is an L-RGB image taken at the start of the session.

Wednesday, March 18, 2009

Saturn 18th March 2009.

Above average seeing tonight, this is a quick process of more to come.

Amazing Hubble Saturn images.

Quad transit of Saturn's Moons.

Credit Hubble.

Monday, March 16, 2009

Saturn 15th March.

Venus 16th March 2009

Getting slimmer.

Sunday, March 15, 2009

OT: White Horse Hill.

Here's a panorama taken from Dragon Hill just below the White Horse, which is just up the road from us.
Larger version here.

Below is the Google Earth view.
Which to my brain shows the opposite relief than what is intended, just like craters that turn into domes on the Moon.

Saturday, March 14, 2009

Venus 14th March 2009.

Wow! that was tricky to find in the glare of the Sun even with my scopes GOTO. It doesn't help that my finder scope is slightly out of focus to my eyes and not adjustable.

Wednesday, March 11, 2009

Saturn 10th March 2009.

Couldn't get very good colours tonight, very odd.
The seeing was average again.

Luminance channel.

Sunday, March 08, 2009

Venus - 8th March 2009.

Again it looks really nice in the EP against a blue background, huge!

Friday, March 06, 2009

The Moons Northern region - 5th March 2009

Here is a view taken from NASA World Wind Clementine data of around the corner.

Thursday, March 05, 2009

Ptolemaeus, Alphonsus, Arzachel - 5th March 2009

Copernicus and ejector - 5th March 2009

9 image mosaic. C9.25, 2.5 x TV Powermate, red filter. Best 350 from 1000 frames, processed in Registax 5 Beta and Adobe Photoshop.

Orions Sword & Belt.

Taken with my Canon 400D and 85mm lens, piggy backed onto my C9.25 mount.

Wednesday, March 04, 2009

Plato in shadow and the Alpine Valley.

Venus 4th March 2009.

Dashed out in between the rain to catch this.
The seeing wasn't up to much and Venus is getting really low in the sky now (so there's lots of rubbish to see through). I thought I'd play around with the DMK camera Gamma settings to see if I could bring out a bit more of the crescent.

Monday, March 02, 2009

Saturn 1st March 2009.

Another night of poor seeing, was clear though ;-)