This is especially necessary during a first look and your ceremony! It is pretty tricky for me to capture the bride coming towards the groom and the grooms reaction all at the same time. Having a second shooter allows me to focus solely on the Bride while the second shooter focuses solely on the Groom.
It is also super beneficial in other parts of the day as well. While I capture the main angles of the bride and groom portraits, my second photographer can get different angles. My second could get a more landscape pulled back shot while I am getting a close up portrait. Or they could be getting a vertical side angle while I get a horizontal front angle. This allows for A LOT more portraits in your final gallery.
I could go on and on, but they also help me out big time during the reception. When speeches are happening, I focus on the essential images. These include images of the individual giving the speech and the bride and grooms reaction. My second photographer will browse the room and capture reactions from your family and friends as the speeches are given.
While I am capturing the beautiful bride and her bridal party getting ready my second shooter can be capturing the groom and the groomsmen getting ready at the same time. This helps tell the full wedding day story! I am sure you are also curious as to what things look like in the grooms getting ready suite.
Having a second shooter can make a huge difference if anything starts to run behind. The second shooter is able to photograph the formal groom and groomsmen portraits. At the same time, I will photograph the bride and bridesmaid portraits. The second shooter can also sneak off to capture reception details while I focus on getting some of your formal portraits.
They also are very good at making sure the family formals run smoothly and as quickly as possible. I always ask for a list of family formal combinations. If we are short on time, I will task the second shooter with wrangling the groups as I photograph. While I am in the middle of one combination they are making sure the next combination is ready to go and everyone is present.