ok so ive been doing aerial scouting on my fields with a Mavic 3 Multispectral for about half a season now and i keep second guessing whether the NDVI data is actually telling me anything i couldnt get from a decent RGB ortho and just knowing what to look for. like yes the NDVI maps look impressive and the color gradients are satisfying but when i ground truth them half the time the stress areas i find are visible in the regular RGB if i zoom in anyway.

i know this probably sounds like a dumb question from someone who just bought expensive equipment and wants to feel validated but genuinely curious if anyone has data on how much earlier multispectral catches stress vs visual. i grow mostly soybeans and some corn, not specialty crops where early detection is worth thousands per acre. at what point does the extra layer of data actually change a management decision vs just confirming what youre gonna do anyway

this isn't a dumb question at all, its actually the right question and most people skip it entirely. the honest answer for corn and soybeans at commercial scale is that the value of multispectral is almost entirely in the consistency and repeatability of the data over time rather than any single flight catching something you wouldnt see in RGB. the NDVI time series across the season is where the insight actually comes from - you're looking for rate of change not just absolute stress level. one flight tells you almost nothing in isolation. if you're only flying a few times a season and not building that time series you're probably not getting full value out of the multispectral sensor yep.

tbh for broadacre soybeans i think RGB plus a good agronomist eye is fine for most scouting purposes. multispectral starts paying off when you're doing variable rate applications and need to feed the data directly into prescription maps, otherwise its kind of just a fancier way to see the same thing. that said the Mavic 3 Multispectral is a great bit of kit and if you already have it might as well learn it properly, the calibration panel workflow takes some getting used to but once its dialled the NDVI repeatability between flights is actually really solid compared to older sensors i used to work with