17 birds with one stone... :) - Page 2

AlexN · #21 18-01-2010, 06:55 PM

Thanks Chris, And congratulations.. You'll love the ST8300 when you get it! I've been nothing but utterly impressed thus far. I've taken only 3 images with it, and thus far, image quality wise I think they are by far my best 3 images... Could it be that a mono camera and filters clearly beats an OSC? or more so that having smaller pixels, resulting in better image scale has had such a dramatic affect? Who knows.. Fact is this... I made a decision back in October of last year, and in hindsight, its perhaps the best decision I've made in astronomy thus far. Never has a piece of equipment impressed me so much... (albeit, this is more like 4 pieces of equipment bolted together... But you know what I mean..)

Cheers mate.. Looking forward to seeing what you can do with the ST8300 + your Taka-Monster rig!

multiweb (Marc) · #22 18-01-2010, 07:15 PM

Nice one Alex. Very busy field.

Octane (Humayun) · #23 18-01-2010, 07:55 PM

Haha, widefield wuss!

Oh, how the mighty have fallen! :tonguepoke:

H

AlexN · #24 18-01-2010, 08:07 PM

Hell yea Humayun... I've really got a taste for this widefield wussy nonsense! I do still want a dirty great big narrowfield setup.. But I don't think I'll ever not have a wide field setup from now on... Limitless possibilities..

Paul Haese · #25 18-01-2010, 09:46 PM

Colour balance buddy is the only thing that needs attention. I would be interested to see a curves adjust too just to make it a little more contrasty and punchy. Nice going. Good to see you imaging.

AlexN · #26 18-01-2010, 09:54 PM

Thanks Paul.. Working on a repro as I type this actually.. Addressing the areas you mentioned and a few other issues...

Doug was right, there was a registration error on the blue frame that was causing stars to look a little strange, and have the blue halo.. This has been corrected. The image currently is a lot punchier, and has a colour balance more akin to Rob Gendlers fantastic image of this area..

Alex

rat156 · #27 18-01-2010, 10:55 PM

Stop typing, finish reprocessing!

For such an expansive FOV you are going to need very good registration, Registar or the CCDStack CCDIS plugin are the only two I would use. You may find that because your using a refractor that only Registar will work properly becuase it can distort the field rather than just rotate and scale it.

Cheers
Stuart

AlexN · #28 18-01-2010, 11:06 PM

Stuart - I've just hit a wall in the repro, and you've hit the nail on the head...

Field distortion is causing real headaches... Looks like I need to buy Registar... I can get the registration pretty good, better than before, but still there are some areas that remain misaligned..

You also hit the nail on the head over at CN too... I will need to refocus between filters despite the filters being Parfocal.. L and R seem fairly close (so close that I could get away without a refocus) however G is slightly out from L/R and blue is out from G..

This will make my imaging runs a little more time consuming, however I suppose personal struggle is part and parcel of the pursuit of perfection..

rat156 · #29 19-01-2010, 07:31 AM

Hi Alex,

Let me try your subs with CCDStack.

You can use www.yousendit.com to transfer the files to me. My email is rat156 and I'm with bigpond.com

That way I can try to use CCDIS to align your subs. I'd like to know if it'll work, if not the Registar is the way to go.

WRT refocusing, the only problem is that your red stars may be smaller than your blue and green, this is not uncommon with refractors I believe. Check the FWHM of a star in you images, make sure it's not saturated though. If the red ones are significantly smaller then you will have to refocus between colour subs or find a "sweet spot" for the colour. Remember that the RGB subs aren't quite as critical as the Luminance wrt focus. In fact as you will probably be binning them, I'd put a little blur on them before combining them anyway (reduces the colour noise).

Cheers
Stuart

ngcles · #30 19-01-2010, 09:25 PM

Hi Alex & All,

Wonderful image of a fantastic field mate. But you've missed several birds and wow, one's a biggie ... in fact possibly the biggest of its type in the Milky Way.

Best,

Les D

AlexN · #31 19-01-2010, 09:54 PM

Thanks Les, Would you mind filling me in on what I've missed out on in my list? I would be very interested to know...

Would one be a dense star cloud? I originally thought this image had odd background noise, but then I realised its actually LOTS of stars.. Deepsky stacker counted 2650 stars in the Lum image...

StarGazing (Alex) · #32 19-01-2010, 10:13 PM

What a photo......... WOW is all that comes to mind

Well done AlexN, Alex

ngcles · #33 19-01-2010, 11:16 PM

Hi Alex,

Quote:

Originally Posted by AlexN

Thanks Les, Would you mind filling me in on what I've missed out on in my list? I would be very interested to know...

Would one be a dense star cloud?

Nnnnooo, not a star cloud.

You missed Cr 240, Hogg 10, Tr 18 and Hogg 12 -- all O.Cs.

But the biggie is at the centre of RCW57 -- NGC 3603. Possibly the most massive and populous O.C in the Milky Way and 20,000 ly away. Westerlund 1 and "The Arches" cluster also vie for that title and a couple of others. NGC 3603 is the probable favourite.

http://hubblesite.org/newscenter/arc...a/format/zoom/

Overview:

http://en.wikipedia.org/wiki/NGC_3603

An intensely interesting cluster containing the star Sher 25 -- a star that will go supernova very, very soon (in astronomical time-scales). Could well be the next Milky Way supernova.

Best,

Les D

Octane (Humayun) · #34 20-01-2010, 02:50 AM

Les,

You and Glen are fascinating resources of information.

Keep on keeping on!

H

pmrid (Peter) · #35 20-01-2010, 04:14 AM

Alex, an image like this is a very eloquent testimonial for your skills but also, for the worth of a well-tuned HEQ5Pro. Those babies are much underrated.
Peter

AlexN · #36 20-01-2010, 07:00 PM

Thanks Peter, I agree. The HEQ5 is commonly seen as a substandard mount for astro photography... I can not for the life of me understand why. The only significant difference between the HEQ5 and the EQ6 is the physical size and load capacity... If you dont load them up, they can be real performers... As with all mass produced "cheap" mounts, they require a bit of a tune up and tweak here and there to get everything humming along how it should, however once thats done they are superb.

I love mine... I'll likely have it for a very long time.