The weather finally cleared for me to be able to achieve first (test) light!
Here are the results from some initial focusing tests that I did last night, mainly to determine the optimal position to drill the holes for the main miror cell. I clamped the main mirror / cell temporarily in the end of the tube, but I still did a reasonable job of collimation. Just the very basic setup at this point; I still also have to paint the tube / some fittings and mount the guidescope / finder / dewcap / filters / fans. I am quite pleased with the results though - a very auspicious start!
I must admit (after a few years designing / building this thing) that I was full of trepidation at the thought of actually performing a real star test
Attached Images:
- First image is the basic scope. I run all 12VDC (13.8VDC to be precise) power through the mount and distribute the power to each individual device via a RigRunner (inside the black enclosure). Similarly, I run a single USB cable through the mount to a powered USB hub inside another enclosure on the other side, which then feeds to each USB device.
- Another image of the scope.
- After finding reasonable focus (trial and error by taking a series of images) I took a series of 9 x 3min luminance of the Horsehead region. I applied dark frames and stacked them, and then just some basic stretching in Photoshop. It should also be noted that I did not turn CCD cooling on - the frames were taken at ambient temperature last night (about 22C). The star images look good right to the corners; the only slight negative I have noticed is some brightening in vane spikes distant but belonging to a couple of bright stars (one off-frame). I believe this is an artefact caused by the unpainted stainless vanes - I have sanded them with wetanddry ready for painting, but they are still highly reflective (especially at grazing angles). I also realised after the tests that I inadvertently used the (slightly) wrong focus position - I was 20 steps (50 microns) off the best position I found. Not much diffierence though, just ever so slightly softer stars.
High Res Image here: http://www.pbase.com/david_fitz_henr...12482/original
- A CCDInspector analysis of one of the raw 3 min subs.
I have also decided on a name for it; follow my process:
Firstly, some relevant terms:
Stellar
AStrographic
High
QUAlity
Telescope
CCD
Selecting some letters to form an acronym:
SASHQUATC --- apply anagram --> SASQUATCH
But that's a northern hemisphere beast, and the analogous equivalent down under would be a BUNYIP perhaps? So, an analogy to an anagram of an acronym
A creature not much mentioned nowadays, so possibly one could say that it is also a bit of an anachronism as well
