Here is the overview of Immigration and Visa counter at Hanoi airport where you pick up Vietnam visa on arrival:

The Vietnam visa procedure at Hanoi airport (Noi Bai airport) is quite simple and straightforward. It normally takes 15 minutes to complete all the process upon arrival. However, in some case, it may take longer because of long traffic of passengers.

Photo service is available at Hanoi airport with around 2 USD/per photo.