https://forum.inaturalist.org/t/how-to-measure-grass-spikelets-in-the-field/52889?u=joshua_sz
“When photographing a wild animal, one cannot put a ruler next to it (the animal might be far away, it might sit on water, or be easily scared away).”
After photographing an animal, another photo of a reference object at the same place can be used to measure the animal。
1 Like