Long time no post! Almost there...

[SimmoW]

Been having a beatch of a time getting the new 10inch F4 scope to work well, mainly caused by probs with the autoguider getting correct focus and being far too flimsy (I bought a 9mm deep TS-OAG9 due to backfocus constraints but it had a number of looseness issues. I wouldn't recommend it unless you are desperate to save millimeters)

So this was the first remotely decent image I've obtained for months. My guiding is still poor imho, as the foam ring setup that Alistair kindly set up for me has deteriorated already, the rest of the setup is rock solid, but if you touch your finger on the OTA you can see it move very easily, it's like imaging with the scope resting on a pillow! So can't wait for the new rings to arrive within a month.

So anyway, enjoy this brief demonstration of my light-sucking setup. 10 inch F4 combined with 8.4 micron sensor buckets. Took 60 shots of 40 seconds, but only 36 of the pics were acceptable due to clouds flitting in and out. So alas, only 24 minutes of OSC. So sad. Will nab this sucker with longer subs and more data if it kills me!

Higher rez (http://www.astrobin.com/318670/)

[strongmanmike]

Imaging on a pillow...aaaah niiice :zzz2::lol:

Simon this is an excellent result, this cluster only looks good when imaged with a scope that has a secondary mirror held by a spider...it's like Christmas :) The final result belies your indicated troubles, well done.

Mike

[SimmoW]

Haha thanks Mike, yes i have to admit i saw all those diffraction spikes and thought 'over the top?!?'

[willik]

Reprocess the spikes they are overwhelming and the pleiades would take on a
new image and look great.Simon
Martin

[Peter Ward]

Is it Christmas already??

Yes, the spikes are big, bold and multi-pronged in some places. But it’s a pretty image. I like it :thumbsup:

[SimmoW]

So anyone know why the spikes are more than 4?

[strongmanmike]

Just looks like scatter to me...? Could be anything, mirror clips, something in the focuser or even from the edge of the aluminising being ever so slightly rough.

Mike

[SimmoW]

Thanks Mike. Luckily it doesnt have mirror clips, just a central bolt at back.

Hmm, i know the very edge of the mirror is slightly rough. How would i counteract that? Flocking the tube?

[strongmanmike]

If it is that and it may well not be, you would need a field stop all around the edge of the mirror, my mirror has one (http://www.pbase.com/strongmanmike2002/image/132998048/original)

[RickS]

That looks great, Simon.



Were you looking down the tube? Could have been the spikes reflecting off your highly polished nut :lol:

[multiweb]

A very fine shot with beautiful colors and details. Not an easy target for a newt. :thumbsup:

[SimmoW]

Haha good one Rick, yeah my bald scone has been known to cause gravitational wave fluctions. Or is it my snoring??

Wow thanks Multi and Rick, and it's still early days.

So could i make a thin field stop with some electrical tape? Dont want to lose too much light gathering or have to attach another contraption!

I learned another lesson that night, i normally use a foam cover for the back of the mirror. That night i didnt bother due to temps.

Some of my early subs had a weird red tinge to them. U realised that as the scope was pointing straight up to the zenith, some tiny red leds were reflecting their way up past the mirror onto the sensor! Gawd, gotta be careful

[strongmanmike]

I wouldn't use electrical tape, maybe a carefully cut (use a sharp blade not scissors) thin black cardboard ring, tape it to the glass edge of the mirror not the coating, only need to cover a few mm of the bevelled edge, all the way around...worth a try.

As for light getting into the back of the scope, I was worried about that too, specifically laptop light getting inside the rear cooling fan openings, so a dark T-shirt taped (http://www.pbase.com/strongmanmike2002/image/157369825/original) to the end of the scope like a curtain did the trick - high tech :)

Mike

[Paul Haese]

I like the wispy detail Simon. Nice colour also.