31 Jul '14, 8pm
DIY USB Spectrometer Actually Works
I also noticed that Renaud is trying to reduce noise from the sensor, I wonder if he’s thought of using ‘dark’ frames to reduce noise? It’s a technique used to reduce sensor noise for astrophotography. Essentially, you make sure that absolutely no light can reach the camera sensor, then capture a number of frames, then put those frames + a light frame (real image) into some astro processing software (Deep Sky Stacker) and it will sum the dark frames and subtract the noise from the light frame giving you an overall cleaner result. dark frames should be taken either before or after taking your images so that the temperature of the sensor is broadly similiar/same to achieve the best results. It’s up to you how many dark frames you take, the more the merrier, as it’s a webcam, you can easily take 1000 dark frames but it’s a law of diminishing returns, 50-100 should be sufficient.