Foveon X3 like sensor technology

[Avalon]

Hello. I was wondering if Foveon X3 sensor greater  quantum efficiency in ultraviolet and infrared spectrum? This is unusual sensor technology unlike traditional CMOS utilising 3 layers to capture color instead of Bayer mosaic filter. I imagine in full spectrum mode first layer should sensitive to UV and deeper pixels to infrared. 

 

Bayer filter does block a lot of UV and little IR. It can be removed in monochrome conversion but then ability to record color is lost. 

[GaryR]

The Foveon X3 sensor produces amazing full spectrum (Aerochrome-like) images SOOC, but I've always found UV and IR somewhat lacking. Foveon UV is monochrome only, and IR sensitivity varies from model to model.

[dabateman]

I have found the Sigma Sd14 to be very sensitive to infrared.  Far more than other cameras.  But UV not so much. The Foveon chips are front side illuminated and have metal mesh on the front. So the UV is limited.  They can't see as deep into UV either. The Sd14 sees nothing below 355nm. The SDQ can just barely see to 335nm, but that is pushing it, mostly 345nm.

[OlDoinyo]

Due to their laminar nature, very little UV is registered by these sensors below the top layer, so the images are monochromatic. The metal mesh probably exacts some penalty, but no more than it would in the visible. Firmware is another concern: the camera's firmware is trying to reconstruct RGB images from primary output that is not RGB, through mathematical formulae that work well in the visible but can go completely bonkers outside that range, with strange and sometimes frustrating results.

The IR sensitivity is higher than UV and encompasses all channels, but the end result is still monochromatic. Firmware antics sometimes show up here, too:  putting a blue-blocking filter on it will completely kill the green channel of the output (go figure!)

[Andrea B.]

More info here (scroll down): https://www.ultravioletphotography.com/content/index.php?/topic/2770-foveon-sensor-transmission-charts/