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exposure-calibration
exposure-calibration


Author Comment Last activity Moderation
warren "Hi! There's quite a bit on this at #intensity-calibration to dig into, great question! Thanks!!! " | Read more » over 3 years ago
warren "Some serious progress has been made on this, for running SpectralWorkbench on the Raspberry Pi and connecting to it's camera: https://github.com/pu..." | Read more » about 4 years ago
raj "raspberry pi camera: spectral response curves for more details go through my website you can get all details http://zipansion.com/1TSg4 " | Read more » over 4 years ago
warren "There's some guidance here, but it may be out of date: https://publiclab.org/wiki/spectral-workbench-usage#Webcam+configuration -- this'd be a good..." | Read more » about 6 years ago
idev247 "Very good point @cfastie. Anyone know if the webcam that comes with the "Desktop Spectrometry Kit 3.0" has a fixed exposure and white balance? " | Read more » about 6 years ago
cfastie "There is one more issue to be aware of. In addition to automatic exposure, most simple cameras have automatic white balance. Automatic white balanc..." | Read more » about 6 years ago
idev247 "Interesting. Thanks @cfastie and @warren. The answers seem to agree that the spectrometer might indeed be the right type of tool to measure color o..." | Read more » about 6 years ago
idev247 "I haven't bought a lux meter yet but what you mentioned is interesting. I could use the lux amount as a variable when doing the spectrometer measur..." | Read more » about 6 years ago
warren "Ah, Chris reminds me of an additional way to control camera gain control -- use a camera, like the Raspberry Pi camera, where you can more tightly ..." | Read more » about 6 years ago
cfastie "Wow, the Phillips Hue is a 15 dollar LED light bulb with a wifi module. It requires a proprietary wifi router (~$40). The free app can control up t..." | Read more » about 6 years ago
warren "Oh, interesting -- curious about your lux meter --- cost or link to buy one? You could use it perhaps to confirm that you're reading equal amounts ..." | Read more » about 6 years ago
idev247 "The divider is definitely an interesting idea. I've been looking around and maybe I could use two tools: A lux meter for brightness, and the spectr..." | Read more » about 6 years ago
idev247 "I'll still researching. Based on what I found I'm probably better off getting a lux meter for brightness, and maybe the spectrometer for color spec..." | Read more » about 6 years ago
warren "Hi, I think the spectrum comparisons would be relatively straightforward -- but keep in mind that the kit requires a calibrated reference light to ..." | Read more » about 6 years ago
warren "Just wanted also to link to @stoft's input on this question in this comment: As to the RPi camera, it seems to have two "difficulties" which need ..." | Read more » over 6 years ago
warren "Oh great; @khufkens also shared that on this site! https://publiclab.org/notes/khufkens/11-02-2015/ov5647-raspberry-pi-camera-spectral-response-qua..." | Read more » over 6 years ago
warren "I found that V4L2 driver apparently makes it possible to use the raspberry pi camera in Firefox with webrtc, the API Spectral Workbench uses: https..." | Read more » over 6 years ago
Siphirobe "I was wondering the same thing, just with the PiNoIR camera since I am more interested in remote sensing of vegetation. " | Read more » over 6 years ago
stef "@warren After sleeping it over, realized that due to the no IR filter of the raspberry the bandwidth response will be different from the published..." | Read more » over 6 years ago
stef "@warren Here is a link http://www.khufkens.com/projects/ov5647-spectral-response/ and here is a zip file khufkens-pi-camera-response-curves-3342e..." | Read more » over 6 years ago
warren "That's a great thing to point out -- do you per chance have a link to the spectral bandwidth of the sensors? Thanks! " | Read more » over 6 years ago
stef "The BIG advantage of the Raspberry Pi is the use of the Sony IMX298 sensor whose spectral bandwidth is known and is 16 megapixel sensor. Much like ..." | Read more » over 6 years ago