| Author | Comment | Last activity | Moderation | ||
|---|---|---|---|---|---|
| CHUMBA | "Hello @cfastie, thanks for your opinion it really help us out. We are so new on this issue, as I commented you on other talk we just broke a camera..." | Read more » | about 9 years ago | |||
| cfastie | "Hi CHUMBA, It looks like the Rosco 116 is a very good filter for NDVI. Compared to the 2007, it passes less red, has a steeper cutoff between red ..." | Read more » | about 9 years ago | |||
| CHUMBA | "Hi I have been testing with one particular filter wich is the 116 Medium Blue Gree, because the 2007 was not available for sale at the moment. I am..." | Read more » | about 9 years ago | |||
| Tbtouaki | "Hi I had wrong white balance for my camera. Thanks everyone for the help. Sorry for the trouble If anyone has any idea on how to save pictures take..." | Read more » | over 9 years ago | |||
| Tbtouaki | "Hi I had wrong white balance for my camera. Thanks everyone for the help. Sorry for the trouble If anyone has any idea on how to save pictures take..." | Read more » | over 9 years ago | |||
| nedhorning | "Chris - Thanks for pointing that out. I typically clip the values so anything greater than 1 becomes 1 and anything less than -1 become -1. " | Read more » | over 9 years ago | |||
| cfastie | "It looks like the computed index will no longer be between -1 and +1 if you adjust the red value that way. Do you then have to rescale the index so..." | Read more » | over 9 years ago | |||
| nedhorning | "Hi Agustin - Your second equation is one option. Another is: (blue- (red-blue0.8)) /(blue+(red-blue0.8)) You can play around with the factor I add..." | Read more » | over 9 years ago | |||
| agustin_castellano | "Sorry is should be (blue- (red-blue)) /(blue+(red-blue)) ?? To extract the nir data in the red chanel. Regards. " | Read more » | over 9 years ago | |||
| agustin_castellano | "Could something like this (blue- (red-blue)) /(blue-(red-blue)) ?? To extract the nir data in the red chanel. Regards. " | Read more » | over 9 years ago | |||
| nedhorning | "Hi Agustin, The formula you wrote is what I use. I typically use the PhotoMonitoring plugin which can be found here: https://github.com/nedhorning..." | Read more » | over 9 years ago | |||
| agustin_castellano | "Hi Ned thanks for your research! Is great this information. i have two doubts. First if i use a red filter how should be the formula (blue - red) ..." | Read more » | over 9 years ago | |||
| fjcaceres | "Chris On last thing on the Agribotix site is that they conclude the best filters are the blue ones Javier " | Read more » | over 9 years ago | |||
| cfastie | "@fgiorlando, I assume the Hoya 25A filters are just as good as Wratten 25A filters for infrared photography. The Hoya glass filters would produce c..." | Read more » | over 9 years ago | |||
| cfastie | "There seems to be a lot of marketing hooey at the Agribotix site. They seem to be doing DIY uncalibrated infrared vegetation index work like a lot ..." | Read more » | over 9 years ago | |||
| fjcaceres | "Because I don't really know much about filters, I came across this company named Agribotix that do NDVI and below the next paragraph is their expla..." | Read more » | over 9 years ago | |||
| Tbtouaki | "Hi I have tried several white balance options before, base on what I've read. On this pics the settings were exactly the same as the maxmax camera...." | Read more » | over 9 years ago | |||
| Tbtouaki | "Hi Sorry for the trouble but how did you proceed to calibrate individual bands to reflectance before calculating NDVI? Did you use "dark object sub..." | Read more » | over 9 years ago | |||
| cfastie | "Hi Rita, Your photo above (NIR1_Red3_b.jpg) will not produce very good NDVI. Most of the pixels of plants have the same value in each of the three ..." | Read more » | over 9 years ago | |||
| Tbtouaki | "Hi I currently have a modified canon (IR block removed) with a wratten 25A Red filter. My pictures are really nice looking but I have big problems ..." | Read more » | over 9 years ago | |||
| fgiorlando | "Interesting stuff indeed, I have been lurking here for a while and trying to build a good documentary NDVI camera for a public gardening project. I..." | Read more » | over 9 years ago | |||
| bwarzak | "Ned, Our company is supposed to be writing an article for Vision System Design magazine regarding uses for dual band filters. I realize that the r..." | Read more » | over 9 years ago | |||
| Thorsten | "I had no problems with using lens filters so far. But it would be interesting if there is some reason to better replace the IR Filter instead. " | Read more » | almost 10 years ago | |||
| nedhorning | "I don't have experience with lens mounted filters but you might get some feedback if you post your question on the plots-infrared list at http://pu..." | Read more » | almost 10 years ago |