Comments

Author Comment Last activity Moderation
cfastie "Congrats Nicholas. That effort getting familiar with CHDK can greatly improve your aerial photos. Two notes on your procedure: Your Powershot was..." | Read more » over 10 years ago
cfastie "I think there are some apps which allow long exposures (Camera FV-5). I guess the calibration photo of the paint would have to use the same settin..." | Read more » over 10 years ago
cfastie "I don't know what the range of your WiFi setup is, but I guess all you need to find out is a tape measure. Have you been triggering the RX100 with ..." | Read more » over 10 years ago
cfastie "Marcelo, I thought Kanarinka was brave to put her Sony Nex 5N on a pole, but threatening to put a new US$750 Sony RX100 II on a balloon goes beyond..." | Read more » over 10 years ago
cfastie "For some reason it's hard to find spectra of glow-in-the-dark pigments. Really, a thousand Public Lab spectrometers out there and no one has done t..." | Read more » over 10 years ago
cfastie "Would the LED have to be placed outside the entrance slit? Otherwise the grating would form an image of the entire bulb. Standard single color LED..." | Read more » over 10 years ago
cfastie "The Canon A2200 (refurbished) is on sale today (November 21) for $48.99 (free shipping) with a one year warranty: http://shop.usa.canon.com/shop/e..." | Read more » over 10 years ago
cfastie "I guess you're right that taking a spectrum of the sun is not going to allow people in Santa Fe and Beijing to compare their peak heights. Simple ..." | Read more » over 10 years ago
cfastie "Hey these infrablues make really nice multispectral images. I am trying new Photoshop tricks. Below is NIR, NBN, and NDVI. You should have some awe..." | Read more » over 10 years ago
cfastie "I think bouncing a light off the surface of a substance is not going to produce atomic or molecular emission. You have to excite the atoms or molec..." | Read more » over 10 years ago
cfastie "No reason to assume that intensity is constant from 400 to 900 nm, because we apparently know that it is not: So use a curve like this and correc..." | Read more » over 10 years ago
cfastie "There are plenty of open sources of spectral data. Some are listed at this Public Lab wiki. I think the NIST database is a good standard with reaso..." | Read more » over 10 years ago
cfastie "Speaking of fluorescent peaks, I just tried your latest peak detection macro on a spectrum of a fluorescent lamp, then tried your new download macr..." | Read more » over 10 years ago
cfastie "Nathan, Would this procedure require a database of known spectra which included the relative (or absolute) strength of each emission peak or just t..." | Read more » over 10 years ago
cfastie "That's a really original design. 80 grams for the rig is nice. I like the way the Picavet arm serves to protect the camera, and the way the camera ..." | Read more » over 10 years ago
cfastie "Mathew, To make sure there is no confusion, the (NIR-Red)/(NIR+Red) formula is not used for the BG3 filter because there is no red visible channel...." | Read more » over 10 years ago
cfastie "Mathew, That does seem to be a consistent pattern. I think you are right that a green filter might offer the purest visible light channel in a sing..." | Read more » over 10 years ago
cfastie "This is a great map. Congrats on the success and especially on getting out to do a trial run. To sort photos by blurriness, sort the jpegs by fil..." | Read more » over 10 years ago
cfastie "Scott is right that georeferencing obliques is usually not very rewarding. Photosynth can be a solution. You can make a "synth" which aligns the o..." | Read more » over 10 years ago
cfastie "Hi Pat, The Wratten 25A is an old standard photographic filter that is still widely available in glass and gel. I think Ned bought a genuine Kodak ..." | Read more » over 10 years ago
cfastie "The aperture mechanism definitely varies among Powershots. By peering into the front of the lens I learned that the high end ones have an actual ir..." | Read more » over 10 years ago
cfastie "I was assuming that the best way to preserve image quality when removing a glass filter would be to replace it with another glass filter. Plastic, ..." | Read more » over 10 years ago
cfastie "Thanks for suffering through this. I just converted two A2200s, and they are quite straightforward compared to your experience. As far as I can see..." | Read more » over 10 years ago
cfastie "Ned, The NDVI image made from the Rosco 2008 photo by stretching the histograms is surprisingly similar to your calibrated NDVI image from the red ..." | Read more » over 10 years ago