Originally Posted by
videomaker
Actually, there may be an exception (depending on the airline), since OP is carrying photo equipment.
This is from the
TSA website
Since that's from TSA, I say that exception is for thru security, not for boarding.
Please also duly noted:
"Air carriers may or may not allow the additional carry-on item on their aircraft. Please check with your air carrier prior to arriving at the airport."
(Emphasis mine)
There are some parallel discussion with this thread over Travel Photography:
Camera Bag as Third Carryon?
From
her/his personal "research",
sefrischling concludes none allows 3rd bag from the 14 airlines in US that s/he spoke to.
Allow me to repeat myself. TSA doesn't operate airlines. Carryon policy goes by each air carrier. I haven't seen any airline stating 3 carryons, photographic equipment or not, are allowed to board in print.