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Groups > sci.image.processing > #4488

Re: spectral cameras

Subject Re: spectral cameras
Newsgroups rec.photo.digital, sci.engr.color, sci.image.processing
References (1 earlier) <MPG.38f6fe4558ef051d98d0cb@news.supernews.com> <d2ffna.40s.19.1@news.alt.net> <d2gcnq.6hm.17.1@news.alt.net> <MPG.38f82819692d38c098d0ce@news.supernews.com> <d2t1b6.a12.17.1@news.alt.net>
From geoff <geoff@nospamgeoffwood.org>
Date 2020-04-13 13:16 +1200
Message-ID <E6idnSyQOYMUIA7DnZ2dnUU7-ffNnZ2d@giganews.com> (permalink)

Cross-posted to 3 groups.

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On 13/04/2020 12:29 pm, dale wrote:
> On 4/8/2020 1:28 PM, Alfred Molon wrote:
>> In article <d2gcnq.6hm.17.1@news.alt.net>, dale@dalekelly.org
>> says...
>>> back to resolution ...
>>>
>>> the visible spectrum
>>>
>>> https://en.wikipedia.org/wiki/Visible_spectrum
>>>
>>> is from 380nm-720nm wavelengths
>>>
>>> if you sample that in 10nm increments, that a low end spectrometer 20
>>> some years ago for approx $10K would do ...
>>>
>>> wouldn't you need 34 dots per pixel? In printing and publishing a
>>> typical rosette pattern CMYK pixel requires 8 dots ...
>>
>> It wouldn't be a good idea to split up each pixel into 34
>> subpixels, each only capturing a very narrow wavelength range.
>>
>> Most incoming photons would not be used, i.e. the sensor would
>> have a low spectral efficiency.
>>
> 
> what about analog capture through a prism then digital rendering in the 
> camera's software driver to the seven optical wavelength colors?
> 
> https://en.wikipedia.org/wiki/Prism#/media/File:Light_dispersion_conceptual_waves.gif 
> 
> 
> red
> orange
> yellow
> green
> blue
> indigo
> violet
> 
> 

That's still quantisation into discrete bands, rather than a truly linear .
geoff

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Thread

spectral cameras dale <dale@dalekelly.org> - 2020-04-07 15:05 -0400
  Re: spectral cameras Alfred Molon <alfred_molon@yahoo.com> - 2020-04-07 22:17 +0200
    Re: spectral cameras dale <dale@dalekelly.org> - 2020-04-07 17:09 -0400
      Re: spectral cameras dale <dale@dalekelly.org> - 2020-04-08 01:24 -0400
        Re: spectral cameras Alfred Molon <alfred_molon@yahoo.com> - 2020-04-08 19:28 +0200
          Re: spectral cameras dale <dale@dalekelly.org> - 2020-04-12 20:29 -0400
            Re: spectral cameras geoff <geoff@nospamgeoffwood.org> - 2020-04-13 13:16 +1200
            Re: spectral cameras Alan Browne <bitbucket@blackhole.com> - 2020-04-13 17:01 -0400
              Re: spectral cameras dale <dale@dalekelly.org> - 2020-04-13 17:24 -0400
                Re: spectral cameras Alan Browne <bitbucket@blackhole.com> - 2020-04-13 18:58 -0400
        Re: spectral cameras Martin Brown <'''newspam'''@nezumi.demon.co.uk> - 2020-04-09 08:42 +0100
  Re: spectral cameras Martin Brown <'''newspam'''@nezumi.demon.co.uk> - 2020-04-08 07:51 +0100

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