M42 - repro

[monoxide]

hey again,
heres another version of my M42 data, getting better but i havent masked the core yet and my flats let me down a bit, anyway its getting somewhere..

any feedback welcome

http://users.on.net/~monox/M42f.jpg
100min no uhc filter

[peeb61 (Paul)]

Very nice indeed...mate, I can get lost in that lot!

What camera are you using and how come you have clear skies?

Paul

[Bassnut (Fred)]

Nice work tj, that huge star halo is actually cool

[multiweb (Marc)]

Originally Posted by monoxide

and my flats let me down a bit

Nice. How do you calibrate your QHY8 subs right now?

[AlexN]

Good shot Tj!

The QHY8 seems to produce those halos for everyone.. at first I thought it was my scope, however I've recently seen a few shots taken with QHY8 + FSQ106 of orion and the horse head, both images had the same halo around brighter stars. So now im sure its the QHY8's filter window...

[monoxide]

thanks guys

glad you like the halo Fred cos i have no idea how to get rid of it anyway

Marc, i've just been doing the calibration in Maxim DL (bias/flat/dark)
after having another look its probably more likely it was just a light pollution issue
i usually use a baader uhc-s but i went without it for a night to see the difference, much better colour but now weird coloured gradients.

[monoxide]

Originally Posted by AlexN

Good shot Tj!

The QHY8 seems to produce those halos for everyone.. at first I thought it was my scope, however I've recently seen a few shots taken with QHY8 + FSQ106 of orion and the horse head, both images had the same halo around brighter stars. So now im sure its the QHY8's filter window...

i was thinking the same thing, but you need that filter there to seal the chamber so i dont know how you'd get rid of it
or mabee it could be the coatings on the filters supplied? anyone tried a baader UV/IR filter on one of these?

[spearo (Frank)]

well done!
Lovely shot and I too like the halo!
On my monitor though I found a slight reduction of brightness and tweak up of contrast seems to bring out the beauty of the shot a bit more
might just be my monitor though
well done
frank

[AlexN]

I've been investigating whether or not I could get an empty nose peice with no filter, but threaded for a standard 2" filter. screw in a baader UV/IR or an astronomik L filter in, and seal it with loctite or something similar.... I'll keep you informed if I find anything.

[monoxide]

thanks Frank, im not sure how well calibrated my monitor is so mabee ill have to check that too.

Alex, dont use loctite!
i use a 2" nosepiece on my qhy8 and that would seal up fine with some gas fitters thread tape but then you have the problem of a lot more air inside the chamber so it would have to be assembled in a *really* dry area or the cold finger inside the camera wont work properly = frosty chip

[AlexN]

The standard nose piece with with the qhy8 seals without anything extra I've found... What I was proposing is one the exact same size as the standard nose piece, except sealed with a high quality UV/IR filter instead of whatever filter is in there standard. No difference to the internal dimensions of the CCD chamber...

[monoxide]

you mean to replace the glass in the standard qhy filter window with baader acf?

i got the extra 'clear' filter when i got my camera so mabee ask theo for one of these?

[multiweb (Marc)]

Originally Posted by monoxide

you mean to replace the glass in the standard qhy filter window with baader acf?

i got the extra 'clear' filter when i got my camera so mabee ask theo for one of these?

I got both the clear and the UV/IR. I use the clear when ever I stack UHC-s or Ha on top of the nose piece. Actually I put the Baader filters before the MPCC then I have a spacer , then the nose piece.

[AlexN]

I use the clear window with Ha filter, I dont get the halos in that configuration, however with the QHY UV/IR, those halos happen very quickly on a bright star.. within 5 min exposures...

[Lester]

Very nice image.