There's a thread on a similar topic but regarding photographing overseas/on holiday. This true incident happened to me at Bishan Park. I was photographing the Treeswift chick in the evening. Light was poor and at a total focal length exceeding 2000mm, I was having a tough time locating the tiny subject.
Along came a young man who was jogging. He saw me and said to me loudly:
"Uncle, can see or not? Need help?"
I was upset and gave him the evil look.
He got the signal and said, "Sure can see or not? Up to you lah." Then he jogged on.