For those interested in Sigma/Foveon ILC spectral reponse

Started 2 months ago | Discussions thread
G Radford Contributing Member • Posts: 926
Re: For those interested in Sigma/Foveon ILC spectral reponse

jande9 wrote:

xpatUSA wrote:

A thread found in the well-respected Andrea B's website:

Covers models from SD9 to sd Quattro and is mainly concerned with the UV/blue region and has some tests other than Foveon's published curves:

http://www.ultravioletphotography.com/content/index.php/topic/2770-foveon-sensor-transmission-charts/

I don't understand those curves. How does the sensor differentiate between different shades of blue when only one layer is responding to it?

I don't know what QE is but the curves for blue and green are parallel in the blue region with no red response. How is the actual shade deduced from that when the ratio between the two remains the same?

The SD14 has a poor UV response. With a UV filter (blocking visible + IR) on my sd Quattro, images are monochrome blue (in color mode), because there is little to no UV sensitivity in the green or red layers. I usually switch to monochrome mode, when shooting UV.

These images taken from your linked site and belong to them.

I don't know what they mean by "green filter".

The 'green' filter, refers to a method of re-creating Kodak Ektachrome Color IR images in one exposure, using a SD1 (dust filter removed) with a Hoya X1 green filter.

Jan

 G Radford's gear list:G Radford's gear list
Olympus E-M1 Sony a7R Sigma sd Quattro H Olympus 14-150 F4-5.6 II Olympus 30mm F3.5 Macro
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