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Groups > sci.image.processing > #4490

Re: spectral cameras

From dale <dale@dalekelly.org>
Newsgroups rec.photo.digital, sci.engr.color, sci.image.processing
Subject Re: spectral cameras
Date 2020-04-13 17:24 -0400
Message-ID <d2vaqk.q8m.19.1@news.alt.net> (permalink)
References (2 earlier) <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> <dsCdnQ8HaYi6TgnDnZ2dnUU7-c_NnZ2d@giganews.com>

Cross-posted to 3 groups.

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On 4/13/2020 5:01 PM, Alan Browne wrote:
> On 2020-04-12 20:29, 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
> <s>
> 
> Everything is trade space. If you sample wider spectrally then you'll 
> likely be under sampling spatially.  Further contribution to noise as 
> well from each discrete sampling location.
> 
> IAC, whether today's cameras are RGB, RGBh or CYGM they seem to capture 
> the colour range more than adequately enough.
> 

RGBW might be something to consider since for example pink hues require 
R and W, that would be R and (RGB)

-- 
Minister Dale Kelly, Ph.D.
https://www.dalekelly.org/
Board Certified Holistic Health Practitioner
Board Certified Alternative Medical Practitioner

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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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