Help me choose an 11" plus setup please

[ngc2403]

am so sorry i didn't see this sooner.

i am currently doing a spectroscopy project using a 16'' LX200 and the lhires III 2400lines per mm, and last year i did a project with the star analyser 100 lines per mm.

personally i would not use the 16''LX200 to image because the mirror is so big and it moves about. plus the problems with that focal lenght is the seeing blurs the spectrum when using the star analyser.

when using the star analyser a newt would be better along with the DSLR as you can take the spectrum of lots of stars at once.

i used an old SBIG ST7 mono parrallel port CCD hellish i tell you now i hope never to use it again. if you would like a copy of the report i wrote for it then you are more than welcome it was for university.

the Lhires III is a very different beast 24 X the resolution and it shows.

we did a spectrum of the sun ~ half of the visible spectrum and it covered over 30 images and is a 29000 by 500 pixel image. it took all day to piece together and is ~200 MP.

compare that to one image for the full specrtum with the star analyser 100.

for star analyser spectroscopy you need;

a big apeature and a focal lenght so that your arc seconds per pixel value is less then the seeing. the later beening the more important. if you use a mono CCD then it is possible to get a rough Quantum Efficeincy Curve for your CCD camera 8) plus you can then go on and do photometry without filters

The Lhires spectroscopy is;

a big apeature and guiding the focal lenght is not as big a worry as it uses a slit. however the lhires it very technical and i would advise that you do the low res star analyser first as it is a good introduction to the world of spectroscpoy plus you can take the spectrum of a Quasar if you are good at it 8)

ally

p.s the SCT's are planet and spectroscopy only in my opinion and a 10'' or 12'' newt is perfect for the low res star analyser plus one a EQ mount you wuld have the perfect DSO set up.

[Whippy]

It would...and the 66 is a nice scope, but ...well , 66mm, is a bit small I think, to complement a 10 inch SCT.. but the 66 is a corking travel scope...and the FOV is superb

Just my thoughts, matching a ZS66 to say a 6 inch or smaller i think would be good.

People who know much much more than I do about optics feel the same way..

Cheers for that Nick .

Tony..

[gurney]

Thanks ally for your thoughts!

I'm really pleased to have your experience added to the discussion. I'm not bothered though about the SCT now, just very happy to have a scope which I think will prove versatile enough to give a very good stab at most things I want to do with it. I think I've learnt enough now to know that there is no one perfect option to cover all bases.

I've seen people getting good results with my setup and the star anaylzer now, so I know it can be done! I've just got to find out how to do it!

When the fairies leave £50k at the end of my bed in the form of pots of gold then I'll get myself setup with the perfect all singing all dancing versatile observatory setup. For now I think I'll stick with the pros and cons of the SCT sheltering from the rain in my study!

And on that front...

I've just gone and picked up a giant superwedge for it! What a beast!!!

[FLO]

I've just gone and picked up a giant superwedge for it! What a beast!!!

Be careful, I know someone who broke his arm carrying one of those down some steps

[Paxo]

I've just gone and picked up a giant superwedge for it! What a beast!!!

Be careful, I know someone who broke his arm carrying one of those down some steps

I've got a megawedge for my 12" and it's more difficult to move about than the scope IMO!

Steve..