Comments

Author Comment Last activity Moderation
cfastie "People post to facebook to get feedback. Facebook posts are not generally intended to help others. Editing a Public Lab wiki does not typically lea..." | Read more » almost 10 years ago
cfastie "The Public Lab desktop spectrometer is quite capable of making a spectral graph of sunlight reflected from grass. The curve will differ from the pr..." | Read more » almost 10 years ago
cfastie "I have not seen a cheap filter like Rosco that is truly a narrow band pass filter. It might be possible to combine filters to get a fairly narrow t..." | Read more » almost 10 years ago
cfastie "A filter switcher is a viable solution, especially for small cameras. Cameras as large as Powershots might require a big, precise device in front o..." | Read more » almost 10 years ago
cfastie "The only filter I tried that worked was Wratten 25A. Two blue filters worked poorly. @mathew has tried Rosco #19 which seems to work well. I don't ..." | Read more » almost 10 years ago
cfastie "It should be possible to distinguish between stressed and non-stressed lawn grass using NDVI. I suspect that the $900 FieldScout performs more or l..." | Read more » almost 10 years ago
cfastie "That is correct that a red filter seems to work much better than a blue filter in a Mobius. The conversion Jeff cited is just for removing the IR b..." | Read more » almost 10 years ago
cfastie "Apparently Onset manufactures HOBOs to be NIST traceable, but they charge more money for units that pass a calibration test. Jeremy buys the less e..." | Read more » almost 10 years ago
cfastie "Bryan, maybe this is what you remember. We deployed a bunch of these in the tundra 15 years ago: . They don't seem that rugged to me. I wonder if..." | Read more » almost 10 years ago
cfastie "That looks like a good arrangement. The DVD grating might have to be rotated. The circular grooves in the DVD (concentric to the outer edge) should..." | Read more » almost 10 years ago
cfastie "That's good to know that structure from motion works with wide angle photos. It sounds like you have to correct the distortion first. It doesn't se..." | Read more » almost 10 years ago
cfastie "That is an excellent Mobius photo. The Mobius is so lightweight that there is no reason not to include one on every flight. The lens is very wide, ..." | Read more » almost 10 years ago
cfastie "I'm not sure what the problem is with that Picavet model. It was designed in Sketchup, and it is scaled correctly in Sketchup, so it is 22 cm long...." | Read more » almost 10 years ago
cfastie "Great report. The mini bottle and 3D printed Picavet will go in the Public Lab record books. And what a fantastic place to fly. Is that public land..." | Read more » almost 10 years ago
cfastie "Those regressions look really encouraging. I guess if I took some photos with my own A2200 and Wratten 25A filter (the same model and filter type y..." | Read more » almost 10 years ago
cfastie "The grating (DVD) bends the light as it separates it into colors. So the grating has to be at an angle to the light coming from the entrance slit. ..." | Read more » almost 10 years ago
cfastie "Hi Chelsea, I don't have much experience with mobile phone cameras or with mobile phone apps, but I have taken a bunch of repeat photos. An app th..." | Read more » almost 10 years ago
cfastie "They sure are. Excel opened the ods file without too much trouble, and the timestamps are right there. I was just curious to look at the data. Don ..." | Read more » almost 10 years ago
cfastie "I had a similar experience when I was figuring out how to copy old film negatives. The best (very expensive) scanner at Middlebury College made a b..." | Read more » almost 10 years ago
cfastie "Oh right, Picasa. Picasa was once my primary photo organizer. Then Google started to link it up with Google+ so it became a front end to storing yo..." | Read more » almost 10 years ago
cfastie "I couldn't get Excel to parse the time stamps either. I averaged every 60 particle counts, so I assume I got a number for every minute. Here is a g..." | Read more » almost 10 years ago
cfastie "This is a really important topic. Scott, what is the program in the main image above? Is that what you use to do the sorting you describe here? Wha..." | Read more » almost 10 years ago
cfastie "It's often quite easy to access the IR block filter on this type of little camera. In this case you might have to also dismantle the UAV just to ge..." | Read more » almost 10 years ago
cfastie "That last setting in the video looks like it might be getting useful. I think the photos will still have more overlap than they need, so you could ..." | Read more » almost 10 years ago