ICEINSPACE
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Moon Phase
CURRENT MOON
Waxing Gibbous 75.4%
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14-04-2012, 09:27 PM
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Registered User
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Join Date: Jul 2011
Location: Melbourne
Posts: 361
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The initial test shots are very promising. The tinkering will well be worth it!
Lucas
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15-04-2012, 12:19 PM
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Highest Observatory in Oz
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Join Date: May 2006
Location: Canberra
Posts: 17,691
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Yeh I agree, considering it is early days, these results are right on track for sure 
Great field of view huh? 
As for your comparison with the AG12 and RHA though, not sure it was all that revealing, animated giffs of jpeg compressed images are always lower res.
Here's that same area at full resolution from the AG12 (complete with details inside Eta herself )
Looking forward to more
Mike
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15-04-2012, 08:32 PM
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Galaxy hitchhiking guide
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Join Date: Dec 2007
Location: The Shire
Posts: 8,484
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Quote:
Originally Posted by strongmanmike
As for your comparison with the AG12 and RHA though, not sure it was all that revealing....
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Agreed... compression artifacts are hiding a whole bunch of data there Bert.
My own (roll-over) comparison showed the AP RHA had stars that were about 30% tighter than an AG12 (using data via Mike's post above)
....but it was and apples and oranges: i.e. meaningless.
Mike's 100% data was decidedly deeper....which will bloat stars in the same instrument, let alone comparing it to a third party with different seeing, focus and who knows what else.
Anyway...Good luck with the scope Bert...I'm sure it will deliver some excellent Wide Field results.
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15-04-2012, 09:50 PM
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Highest Observatory in Oz
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Join Date: May 2006
Location: Canberra
Posts: 17,691
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Quote:
Originally Posted by Peter Ward
Agreed... compression artifacts are hiding a whole bunch of data there Bert.
My own (roll-over) comparison showed the AP RHA had stars that were about 30% tighter than an AG12 (using data via Mike's post above)
....but it was and apples and oranges: i.e. meaningless.
Mike's 100% data was decidedly deeper....which will bloat stars in the same instrument, let alone comparing it to a third party with different seeing, focus and who knows what else.
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That's very interesting Peter, I'd like to see the 100% RHA data for the above field along side the 100% AG12 data actually and not as a roll over though and neither coregistered ie warped by software either, just cropped as close as possible to the same field...I'm intrigued 
Mike
Last edited by strongmanmike; 15-04-2012 at 10:02 PM.
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15-04-2012, 10:51 PM
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Galaxy hitchhiking guide
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Join Date: Dec 2007
Location: The Shire
Posts: 8,484
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Quote:
Originally Posted by strongmanmike
That's very interesting Peter, I'd like to see the 100% RHA data for the above field along side the 100% AG12 data actually and not as a roll over though and neither coregistered ie warped by software either, just cropped as close as possible to the same field...I'm intrigued
Mike |
Sorry, already did a rollover... but I didn't knowingly warp any data...just registered an up-scaled crop by 200% for my own curiosity...
Resulted in big, non-web friendly files, hence the roll-over response is not instant.
Here is the link
I frankly couldn't glean much, as the RHA data is quite short, with zippo processing other than scaling.
I can see layered masks and all sorts of other processing in the AG12 image.... hence my comments on the link above. i.e. I think the comparsion has no quantitative value.
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15-04-2012, 10:59 PM
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Highest Observatory in Oz
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Join Date: May 2006
Location: Canberra
Posts: 17,691
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Quote:
Originally Posted by Peter Ward
Sorry, already did a rollover... but I didn't knowingly warp any data...just registered an up-scaled crop by 200% for my own curiosity...
Resulted in big, non-web friendly files, hence the roll-over response is not instant.
Here is the link
I frankly couldn't glean much, as the RHA data is quite short, with zippo processing other than scaling.
I can see layered masks and all sorts of other processing in the AG12 image.... hence my comments on the link above. i.e. I think the comparsion has no quantitative value. |
Hmm? ya can't really do it like that, which ever one was coregistered will be blurred, you need to take the plain non coregistered just 100% res (not upscaled) jpeg data from the two scopes and place them side by side, once you upscale and coregister etc it introduces all sorts of issues....
Mike
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15-04-2012, 11:35 PM
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Galaxy hitchhiking guide
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Join Date: Dec 2007
Location: The Shire
Posts: 8,484
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Quote:
Originally Posted by strongmanmike
Hmm? ya can't really do it like that, which ever one was coregistered will be blurred, you need to take the plain non coregistered just 100% res (not upscaled) jpeg data from the two scopes and place them side by side, once you upscale and coregister etc it introduces all sorts of issues....
Mike
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Sorry, that makes no sense to me.
Either way, the transformation is linear with stacking (ie rollover) or side by side presentation. All you are doing with a rollover of same-scaled data translating it, from side-by-side to upper-lower.
An up-scale (2x) transform is also linear....and simply makes a 3mm stellar footprint look like a 6mm one.
Having pictures side-by-side or on-top of each other doesn't change the intrinsic data.
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15-04-2012, 11:44 PM
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Highest Observatory in Oz
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Join Date: May 2006
Location: Canberra
Posts: 17,691
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Quote:
Originally Posted by Peter Ward
Having pictures side-by-side or on-top of each other doesn't change the intrinsic data.
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I think it does, if you coregister one image to the other the one co registered will be warped to match the base image and this blurs the data a little, plus why the 200% upscale anyway?
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16-04-2012, 12:07 AM
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Galaxy hitchhiking guide
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Join Date: Dec 2007
Location: The Shire
Posts: 8,484
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Quote:
Originally Posted by strongmanmike
I think it does, if you coregister one image to the other the one co registered will be warped to match the base image and this blurs the data a little, plus why the 200% upscale anyway?
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Linear Algebra 101. If what you suggest is true then RGB combining or stacking of multiple images is doomed to fail with anything less than perfectly aligned raw data (mine sure as heck isn't)
The 200% upscale was simply so I could see foot-print changes better...the relativities stay the same.
In any event Mike, it's a silly comparsion...(sorry Bert) as they are simply too many variables (seeing, filter homogeniety & figure, data depth, processing etc. etc. ) to draw any meaningful conclusions.
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16-04-2012, 12:13 AM
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Highest Observatory in Oz
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Join Date: May 2006
Location: Canberra
Posts: 17,691
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Quote:
Originally Posted by Peter Ward
Linear Algebra 101.
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You like dragging my images into comparisons don't you Peter...I'm flattered that you take such close notice 
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16-04-2012, 11:16 AM
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Galaxy hitchhiking guide
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Join Date: Dec 2007
Location: The Shire
Posts: 8,484
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Quote:
Originally Posted by strongmanmike
You like dragging my images into comparisons don't you Peter...I'm flattered that you take such close notice
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I often compare FWHM's from many different (web) images... so no need to fret, your work is just one of many sources I use to sus-out how various instruments may perform.
Plus, Bert started the process... and you asked for something (similar) that I would not have otherwise posted.
Last edited by Peter Ward; 16-04-2012 at 12:13 PM.
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