When putting in the location of an observation, how close should I try to get it to the true latitude and longitude. If the answer is in the neighborhood of 100 meters or less, what coordinate system should I be using? Should it be ITRF/WGS84?
iNat uses WGS84. Try to get the coordinates as close as possible, then use the accuracy circle radius to make sure the area where you saw it is covered.
Then there’s the question if one should leave the location as that of the camera or alter it if the position of the target is distant. That’s relevant biologically in the context of birds photographed through big telephoto lenses, for instance.
I sometimes cut off a small branch from a tree and take it someplace where I can get a better picture (if I own it or have permission). I have to be sure to use the location of the plant, not the place where the picture is taken. I also may take the branch home and study identification guides before submitting an observation.
Location should be for the focus of your picture, not you.
I will stress the mentioned accuracy circle. I sometimes loose the exact coordinates for some reason. But even broader location is fine. Just when you know only that it was somewhere in a broader area, just set the accuracy circle to this broader area.
This can also be used to hide the exact location, where the official hiding would be unnecesarily strong. E.g. it is well known the the vulnerable plant grows somewhere on this hill - mark the whole hill and place the coordinates somewhere in the centre. That does loose the exct coordinates even for trusted experts but they often already know or can easily find out where these grow. Or they can also contact you.
Thanks, I’m just getting started, so had not noticed the accuracy circle. I checked my 4 observations and edited the location and accuracy circle on 3 of them.
More important than the accuracy of the location is the accuracy of the habitat/biotope. Like for underwater observations. Along a uniform coastline it doesn’t matter much if your location is 50 metres off. But it matters a lot if you are setting a fish to dry land, even if it is only 5 metres off …