There was some conversation at the gate, but after getting a supervisor to clarify the rules, I got in. The gate attendants apparently have a ruler marked for 4.5 inches. He was measuring the length of the lens, but the supervisor clarified it that it's the lens opening width that's measured.
|AT-6 Harvard by jarud|
from Trainer aircraft
|Monarch butterflies winter roost at Pismo Beach by cjf2|
from Safety in Numbers (Nature)