I guess Edmund means “Cosine Fourth” Law for Falloff. On Mar 15, 2016, at 3:03 PM, Roger Breton wrote:
"sin 4", is that "Sinar 4"? Some kind of Sinar software, Edmund?
/ Roger
-----Original Message----- From: colorsync-users-bounces+graxx=videotron.ca@lists.apple.com [mailto:colorsync-users-bounces+graxx=videotron.ca@lists.apple.com] On Behalf Of edmund ronald Sent: 15 mars 2016 14:21 To: Ben Goren <ben@trumpetpower.com> Cc: ColorSync <ColorSync-Users@lists.apple.com> Subject: Re: Spectral sensivities
sin 4
On Tuesday, March 15, 2016, Ben Goren <ben@trumpetpower.com> wrote:
On Mar 15, 2016, at 9:39 AM, Roger Breton <graxx@videotron.ca <javascript:;>> wrote:
Is there a (simple) way to get at a particular camera sensors spectral sensitivities?
Simplest is to get it from somebody else.
Cheap is to build your own large-sized spectroscope, photograph a spectrum, and combine it with various other measurements and math and what-not. I still need to type up and post instructions and plans and what-not. But the basic idea is that if you know the SPD reaching the sensor (which is a product of the illuminant and the efficiencies of everything between the illuminant and the sensor -- presumably, just the diffraction grating and the lens) then you can treat the rainbow image as a standard chart image to get your RGB values. Assuming the sensor is linear (a good assumption if your capture technique is impeccable), that's your spectral sensitivity.
Cheers,
b&
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