I am doing some work with detecting infrared LEDs (like found in a TV remote). I notice on my Lumia 920 I can detect an infrared LED but its quite dull, I am guessing that there is a partial IR optical filter on it (like on many new smartphones and digital cameras). Can anyone confirm this?

I have also ordered a 520 to see if this has the same issue. Does anyone know if this has an IR filter, and if it does can it be carefully removed with a bit or work, or is it a sealed unit?

FYI, I am using a 850nm filter to detect the LEDs, which therefore cuts all visible light out but lets infrared through - so I can simply see a white dot (the LED) on a black background, with a bit of thresholding of the image.

Thanks! Any help from anyone doing something similar with Lumia's would be great!