Banana Scope Rosette

[MarkS]

Here's a first light from the Tak Epsilon 180ED taken on Sunday night from Sidcup between clouds.  500mm focal length at F2.8

Ha-modified Canon EOS 350D (with Peltier mod removed) and 12nm Astronomik Ha filter.
20x2min subs.  Stacked in IRIS with darks and flats.  The first sub was taken 90 minutes after transit so it was already dropping low in the sky (increasing the background sky glow).



The focus is not good - it started off spot on but then drifted (probably as the temperature dropped) - you can see that the diffraction spikes are not as sharp as they should be.
The collimation is not yet perfect - on the full size image you can see elongated stars and fuzzy diffraction spikes especially towards the left hand side.  I'll tackle this again at the weekend with both a laser and a Cheshire.
On the full size image you can also see that the flat is not very good - it is still dark towards the corners.
Also I should have have taken longer subs.

But, all those excuses aside, I'm pretty pleased with the result.

Here's the full size version:
http://www.markshelley.co.uk/webdisk/tak_rosette14032010.jpg

Mark

[Fay]

Mark that is fantastic, I would be well pleased with that. 2mins subs!!!!!!

[JohnP]

Mark - You must be well chuffed - doesn't look like there is a lot wrong to me (apart from slightly mishapen stars on full size) - Looks like this scope with your EOS will be a killer combo once you make your final tweaks & get it under some dark skies.

John

[The Thing]

Mark, this looks lovely with the trails of wispiness off the edges. The slight 'twinkles' add a natural sparkle to the centre.