| Author | Comment | Last activity | Moderation | ||
|---|---|---|---|---|---|
| cfastie | "(I'm reposting this as an "Answer" because a bug is preventing "Comments" from displaying sometimes.) Hi Stevie, @xose is right about snow and ic..." | Read more » | almost 8 years ago | |||
| cfastie | "Hi Stevie, @xose is right about snow and ice making exposure tricky. The glare from an ice surface can also be a problem with exposure, but that w..." | Read more » | almost 8 years ago | |||
| cfastie | "Hi Stevie, The plants you choose probably won't make much difference in water storage during storms because they can't absorb water fast enough. T..." | Read more » | almost 8 years ago | |||
| cfastie | "Calibration probably requires that your photo includes a target of known spectral reflectivity in the bands that will be used to compute NDVI. More..." | Read more » | almost 8 years ago | |||
| cfastie | "Which software are you referring too? " | Read more » | almost 8 years ago | |||
| cfastie | "Jurist, I tried to calibrate your spectrum but Spectral Workbench would not complete the task. I don't know why it did not work. The intensity sc..." | Read more » | almost 8 years ago | |||
| cfastie | "Do you have some reason to think that the spectral output of the lamp should be different? Maybe the result you got is a good representation of wha..." | Read more » | almost 8 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 » | almost 8 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 » | almost 8 years ago | |||
| cfastie | "Video editing programs usually have some way of converting photos into the frames of a video. In Adobe Premiere Elements if you click Add_Media/Fi..." | Read more » | almost 8 years ago | |||
| cfastie | "I don't know whether a macro in Spectral Workbench could capture images at some interval from a continuous video stream from a webcam (spectrometer..." | Read more » | almost 8 years ago | |||
| cfastie | "Many plant species have leaves with broadly similar spectral reflection properties. So depending on the species it might be a challenge to distingu..." | Read more » | almost 8 years ago | |||
| cfastie | "Depending on your goal, a spectrometer might not be needed to locate dandelion flowers. They are dramatically distinct from green leaves in the vis..." | Read more » | almost 8 years ago | |||
| cfastie | "It's very easy to convert a photo from a red-filtered Mobius (or other) camera to color NDVI using the Photo Monitoring plugin for Fiji: https://pu..." | Read more » | about 8 years ago | |||
| cfastie | "I'm using formula ndvi= Nir-Vis/Nir+Vis The formula for NDVI is NDVI=(Nir-Vis)/(Nir+Vis) Vis= Blue channel Nir= red channel With a red filter,..." | Read more » | about 8 years ago | |||
| cfastie | "Hi Mario, White balance could be a problem. All of those preset white balance settings and the results from auto white balance will be very differe..." | Read more » | about 8 years ago | |||
| cfastie | "If you collect all the water expelled while a laundry machine washes a load of clothes, all of the synthetic material will be in the water. If you ..." | Read more » | about 8 years ago | |||
| cfastie | "Mario, After the internal filter has been removed, a new filter can be used either inside the camera or in front of the lens. It's hard to keep the..." | Read more » | about 8 years ago | |||
| cfastie | "I need some help with your questions. What is the name of the product you bought from Public Lab? Do you want to modify the camera on your DJI Pha..." | Read more » | about 8 years ago | |||
| cfastie | "Hi Robert, In this note and comments we were lamenting the lack of replicate spectra of CFL lamps to confirm the information at the Wikipedia page...." | Read more » | about 8 years ago | |||
| cfastie | "I have one of the first Mobius cameras that Public Lab bought to test. It has the standard lens. I removed the IR cut filter (note) and then after ..." | Read more » | about 8 years ago | |||
| cfastie | "Abdul, It is possible that the new lens has different coatings which alter the color balance (red:NIR). This might require an adjustment to the cus..." | Read more » | about 8 years ago | |||
| cfastie | "Thanks Pat, I recall that you might have tried Meshlab with this type of data. Were you able to do some quantitative analysis (e.g., volume) with M..." | Read more » | about 8 years ago | |||
| cfastie | "The lamp post, the wall, and parts of the tree trunk are all very dark. It is a common artifact that NDVI computed for dark areas of photos is not ..." | Read more » | about 8 years ago |