Comments

Author Comment Last activity Moderation
funkycbj "I just used a StellarNet spectrometer to find the transmittance of hot filters from the Canon A2200 & A2500. Both hot filters rapidly fall off ..." | Read more » almost 9 years ago
funkycbj "A blue filter will give better results if red or yellow flowers are present because the flower reflectance mixes with the leaf reflectance and defl..." | Read more » almost 10 years ago
funkycbj "Just so you know, 720nm is in the "red edge" region so you're not computing NDVI. You are computing the Normalized Difference Red Edge Index (NDRE). " | Read more » about 10 years ago
funkycbj "Light is transmitted but it is diffusely scattered past a certain depth, which seems to be ~7mm. The minimum thickness increases with the size of ..." | Read more » about 10 years ago
funkycbj "Krylon extra flat black spray paint is diffuse and spectrally flat across the vis-nir. A small sheet of teflon isn't too expensive and works great ..." | Read more » about 10 years ago
funkycbj "You want to capture enough spectral variation between different surface features. If you only have 2 bands but have several classes then you may ge..." | Read more » over 10 years ago
funkycbj "If you take pictures at higher angles (more perpendicular and less oblique) you may achieve a more Lambertian response. Dealing more directly with ..." | Read more » over 10 years ago
funkycbj "I noticed that you are capturing your test images from an oblique angle. Bidirectional reflectance at that angle may be creating "hot spots" in you..." | Read more » over 10 years ago
funkycbj "A blue filter should be an acceptable alternative to a red filter when measuring vegetation if the spectral response of the blue filter is sensitiv..." | Read more » over 10 years ago