How much light gets through a CFA ...

Started 3 weeks ago | Discussions thread
Flat view
xpatUSA Forum Pro • Posts: 19,066
How much light gets through a CFA ...

... would like to calculate it myself based on a known source of light and published spectral transmission curves - having gotten thoroughly confused elsewhere. But first I need to be sure of basic principles, to which end I drew this:

In the above, the x-axis is wavelength and the y-axis is power per area per unit wavelength. The brown line represents an hypothetical source of light and the L-shape represents a CFA color segment, obviously nothing like the real thing.

If I am on the right track, I'm thinking that the effective wavelength of the L-shape can be represented by it's centroid which is somewhere on the line between the two red dots. Taking moments of the two rectangular areas which make up the 'L', I get xc as the moment arm, ergo, yc is the effective transmission factor of the CFA color segment.

Here's where I get less sure of myself. Does projecting xc upward to where it intersects the light source spectral curve tell me the effective power transmitted? A gut feeling says not - as I am aware that, theoretically, I should do the Reiman strips thing and multiply the results then average them.

[edit] For the purposes of any discussion, I am not referring to photon capture by the sensor, meaning that QE is not a factor, per se.[/edit]

Any help or references would be appreciated ...

@bobn2 - please excuse any insufficiently precise terminology ...

-- hide signature --

Pedantry is hard work, but someone's gotta do it ...

 xpatUSA's gear list:xpatUSA's gear list
Panasonic Lumix DMC-LX1 Sigma SD9 Sigma SD15 Panasonic Lumix DC-G9 Panasonic Leica DG Macro-Elmarit 45mm F2.8 ASPH OIS +14 more
Flat view
Post (hide subjects) Posted by
Keyboard shortcuts:
FForum PPrevious NNext WNext unread UUpvote SSubscribe RReply QQuote BBookmark MMy threads
Color scheme? Blue / Yellow