From: Ray Byrne <ray@in4media.co.uk>

Date: February 6, 2010 6:01:00 PM MST

To: Astro_IIDC@yahoogroups.com

Subject: Re: [Astro_IIDC] Re: Damian Peach

Hi Mark,

Thanks for the "heads-up" on the sunspot. I'll dust-off my 4" APO and Herschel wedge.

Ray

On 6 Feb 2010, at 22:50, Mark Gaffney wrote:

Hi Ray, 

I had it apart & did attempt collimation but basically satisfied myself with first getting the moon in focus, then Jupiter then getting a pinpoint accuracy of a star through the eyepiece. I did de-focus & look at the doughnuts & got concentrc rings with as little dark shading as I could on either side (passing through focus to the other side each time). I have Metaguide`s collimation tool to try (which is done using your TIS camera & a PC). It`s a guiding app so will keep your star centred whilst you`re doing it if you wish. I`ve got the scope polar aligned again now so I`ll give Metaguide a go next chance I get to clear up the doubts altogether. Previously finding & tracking stars for use in collimation wasn`t a goer at all...By the way I notice there`s a big new sunspot # 1043 developing in the NW of the sun, I`m hoping will stay around for when this rain here clears. I`ll make sure I`m wearing a hat next time & put in a request for some Aeroguard repellent for the march flies..!

Mark.

On 07/02/2010, at 9:20 AM, Ray Byrne wrote:

Mark,

Possibly the reason you aren't totally happy with the results you get IS your attitude to collimation. Get it spot on! it's easy enough don't buy a load of expensive gear before getting yourself some Bob's Knobs and get your scope collimated you'll be amazed at the difference it makes. You need to choose a third/fourth magitude star and use high magnification and just get those rings concentric. You'll see by the shadow of your arm in the eyepiece which one to tweak. You've said that you have had your scope apart before so you must have collimated it then? the C9.25 hold collimation really well so it only ever requires very small adjustment once a good collimation has been achieved the once.

Seeing is the main enemy which you can't do much about, focussing and collimation are down to you and you can get this perfect with a bit of effort.

Come on man the "it'll do" attitude is no good to us astronomers ;o]

Ray

On 6 Feb 2010, at 18:01, Mark Gaffney wrote:

As to collimation my attitude has been well enough is good enough. I always get carried away with imaging when I get a good night at the expense of these fine adjustments. I mean I can see the moon clearly (it`s in focus OK) & stars are pinpoint enough to my eye. But Jupiter through the barlow was disappointing so maybe I`ll have to make some time to check it. As usual otherwise I`m finding things to buy at a great rate, far in excess of my budget..!