Greg's Observatory in the New Forest

[wingeing Pom]

Hi guys,

Radar asked if I would post some pics of my setup as there are a few observatory fanatics among you it would seem :) I love them too, and I think the fibreglass dome in my garden looks really cool, even if my missus does call it a Portaloo!!!!

Here's the dome:
http://img199.imageshack.us/my.php?image=observods7za.jpg

Here' the custom-built (courtesy of the University workshop - oops) all-Aluminium pier:
http://img164.imageshack.us/my.php?image=newpier5fr.jpg

Now you can see the reason for the strange pier shape, it fully supports the (not so good Celestron "Heavy-Duty" wedge) and at the same time puts the centre of mass of the scope above the main support.
http://img164.imageshack.us/my.php?image=pierpluswedge6ri.jpg


Here's a few minutes after the heart-stopping time when I took a drill to my almost new Celestron 11 GPS to fit the adjuster rods so I could collimate the Hypserstar. I needed to put black tape around the rod threads to prevent funny diffraction patterns around stars.
http://img145.imageshack.us/my.php?image=hyperstarxyimg8et.jpg

I don't use the Hyperstar at present so the C11 is a guidescope! I use a Sky 90 and SXVF-M25C for wide field imaging. The loss of speed from the Hyperstar is tragic, but the SKy 90 at f#4.5 does seem to give good shaped stars across the FOV (with a touch of vignetting). The Hyperstar always suffered from some Coma in the corners, something you have to put up with in low f# systems I think.

I'll post more bits as I come across them.

All the best,
Greg

[Radar]

Thanks for posting Greg. So what F ratio does that CCD camera mounted on the front of the C11 work at?

Also funny how the C11 is currently the guidescope.

[wingeing Pom]

Hi Radar,

The Hyperstar setup works at an extremely fast f#1.85 !!!!!
The word I use for using the C11 as a guidescope is "perverse".
All this stuff is discussed in a book to be published by Springer this September:

http://www.springer.com/west/home/generic/search/results?SGWID=4-40109-22-173729312-0

There is also a Noel/Greg "coffee-table" picture book due this year (private publishing), and Noel has a contract for an image processing book with Springer.

All the best,
Greg

[Radar]

Wow, 1.85! That is fast.

Also what where the diffraction patterns like when you first installed the hyperstar? I imagine the screw threads where giving the diffraction spikes jagged edges? Do you have an image of this?

Cheers

Ray

[wingeing Pom]

HI Radar,

The diffraction pattern was much more complicated than that funnily enough. It gave a "box" around the brightest stars with the edges of the box being made up of fine lines. I took this image ages ago, and the resolution will be down on the original, but you can just about make out the box (without the fine lines) around the brightest star:
http://img252.imageshack.us/my.php?image=ngc7000vertical6ty.jpg

Taping over the threads got me back to the standard 4-spike diffraction pattern you would expect :)

All the best,
Greg