A better explanation?
Greg Chalik
(08 Nov 2014 21:27 UTC)
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Re: [TML] A better explanation?
Craig Berry
(08 Nov 2014 21:31 UTC)
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Re: [TML] A better explanation?
Ash
(08 Nov 2014 21:37 UTC)
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Re: [TML] A better explanation?
Craig Berry
(08 Nov 2014 21:39 UTC)
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Re: [TML] A better explanation?
Brad Rogers
(08 Nov 2014 22:15 UTC)
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Re: [TML] A better explanation?
Craig Berry
(08 Nov 2014 22:25 UTC)
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Re: [TML] A better explanation?
Brad Rogers
(08 Nov 2014 23:37 UTC)
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Re: [TML] A better explanation?
Bruce Johnson
(08 Nov 2014 21:49 UTC)
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Re: [TML] A better explanation?
Greg Chalik
(08 Nov 2014 22:12 UTC)
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Re: [TML] A better explanation?
Tim
(08 Nov 2014 23:14 UTC)
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Re: [TML] A better explanation? Timothy Collinson (12 Nov 2014 14:06 UTC)
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Re: [TML] A better explanation? Timothy Collinson 12 Nov 2014 14:06 UTC
> On 8 Nov 2014, at 23:16, Tim <xxxxxx@little-possums.net> wrote: > >> On Sun, Nov 09, 2014 at 09:12:25AM +1100, Greg Chalik wrote: >> Bruce, thank you for the explanation. >> What other filters are there aside from the RGB? > > There are 80 filters applicable between two different sensors. > > >> So what would the image look like to the naked eye? > > That's hard to say without using filters that gather data suitable for > approximating the eye's spectral response. Since most of these sorts > of astronomical phenomena tend to have low luminance, probably "black" > or at best "a faint grey smear that you can barely see if you look > slightly away from it". The article suggests that with a telescope > that gathers a lot more light than naked eyes can, it would look > pinkish. > > >> And, why is studying these clouds in a given filter so important? > > Our eyes suck at frequency discrimination, as do the raw, unfiltered > sensors. > > Filters allow specific wavelengths to be studied and compared, giving > much more detailed information about the processes that produced the > light. E.g. relatively cool thermal radiation (at "only" a few > thousand K) tends to have a broad, smooth spectrum of a known form. > At higher temperatures we tend to see only the visual/UV part of the > spectrum, often dominated by ionization and recombination lines at > specific wavelengths, and so on. Many thanks Tim. That's a really helpful (and clear!) explanation. tc