Ultra 2 will not detect motion moving parallel to lens

[cypress708]

Will not detect a Kubota M108S tractor (90" wide x 106" tall) slowly backing out of a tractor bay, starting from 15' away from camera.  Will not detect same tractor slowly pulling into same bay.  

Similar experience with Ultra 2's with personnel slowly approaching parallel to lens.

[jguerdat]

Detection requires sufficient IR output as well as sufficient movement across the PIR segments, just as with any other PIR motion device.

https://kb.arlo.com/1015583/How-do-I-optimize-motion-detection-for-my-Arlo-camera