histogram
histogram


Author Comment Last activity Moderation
batuhanbozuntu " Php Script " | Read more » about 2 years ago
cfastie "Setting a custom white balance on the Mobius camera can be done numerically. Determining which numbers to use requires trial and error and subjecti..." | Read more » over 5 years ago
suman "Dear Cfastie, Very informative. Thanks for posting. I was interested to know, which method is more preferred and accurate, whi..." | Read more » over 5 years ago
WhiteRabbit "Interesting results! " | Read more » about 8 years ago
cfastie "You're right, that would be a revealing test. In the example you referred to (below), the red channel should be three times more sensitive than th..." | Read more » over 8 years ago
ttaylor "you know, if the little color filters in Mobius cmos sensor Bayer array have the same spectral response as some of the CCD sensors I've seen around..." | Read more » over 8 years ago
ttaylor "Wow, that was quick. Too bad about the Mobius not doing raw. I feel like a I have decent handle on the Canons, but the Mobius is so light and po..." | Read more » over 8 years ago
cfastie "Tom, Maybe it would also be useful to you to have DNG images (via CHDK) from my full spectrum Canon A810? " | Read more » over 8 years ago
cfastie "Hi Tom, I didn't capture RAW with the S95, and the Mobius does not do RAW (although the firmware is open source, so it's possible). I could capture..." | Read more » over 8 years ago
ttaylor "Chris, do you have raw versions of these images I could look at? " | Read more » over 8 years ago
mathew "I'm matching your process from here- got to go grab the rosco filter packs from storage, but I just printed up that beautiful mount. " | Read more » over 8 years ago
mathew "I'm surprised at the IR passing of the Powershot. nice research. really should buy some of those NIR LEDs myself. " | Read more » over 8 years ago
warren "...the plant pixels will have the biggest values for both R and B and the difference between them is therefore likely to be bigger. Yeah, the idea..." | Read more » over 8 years ago
PeeBee "Thanks cfasie. I understand now the exposure issue you raise. But you seem to assume the different exposures are an unknown, which it strikes me ..." | Read more » over 8 years ago
cfastie "To compute NDVI, you have to know the relative amount of light in a visible and an NIR band being reflected from plant leaves. The difference betwe..." | Read more » over 8 years ago
air_maiden "I too am interested to see whether a non-modified camera and a camera with the IR filter removed can be used to calculate NDVI. Could you please cl..." | Read more » over 8 years ago
cfastie "That's a really clever idea, and I think it might work. However, it assumes that: The photos must be simultaneous if anything in the scene is cha..." | Read more » over 8 years ago
PeeBee "Thanks cfastie. I don't think I understand the need for the Wratten filter. My understanding is: A camera with just the IR filter removed (i.e. n..." | Read more » over 8 years ago
ttaylor "Ned, each "red" pixel in a 2x2 block typically has an intensity about 50% bigger than the either of the two "green" pixels in the same block. The t..." | Read more » over 8 years ago
nedhorning "Nice post. It would be neat to characterize some of these cameras. I made a half-hearted attempt a while back to access the necessary equipment but..." | Read more » over 8 years ago
cfastie "I see what you mean when you say that the difference between the blue and red channels is correlated with the presence of plants. Your monochrome i..." | Read more » over 8 years ago
warren "In short, while you've clearly shown there is IR in all 3 channels, there is still a reasonably good signal/noise ratio difference between 2 channe..." | Read more » over 8 years ago
warren "Thanks Chris, but I'm not sure I agree that we're just seeing brightness due to infrared. I'm not saying this is NDVI -- it seems to work in the re..." | Read more » over 8 years ago
cfastie "If you have two cameras, and your goal is NDVI or false color infrared, the best way to get what you need is one unmodified camera and one with the..." | Read more » over 8 years ago