I am going to be honest: Although it should not be the case, it is not that improbable that a guest might take the "best" shot at your event. So why hire a professional for your event?
Consistency and professionalism.
Doing something professionally vs doing something as a hobby are two very different things. The hobbyist may take amazing images, but that does not mean that they know how to provide professional services. It takes years of experience and quite honestly the right personality to be a professional photographer.
Heres a list of things a professional photographer brings to the table
- experience which translates to an understanding of potential variables and challenges
- CONSISTANCY! a professional photographer is consistent. This comes from a mastery of their craft.
- Ability to work under pressure. Mastery of the craft means the photographer is equipped for all conditions. The best solution might not be great, but the experienced photographer at least knows what it is.
- Ideally they bring a personality that fits with the high demands placed on a professional. This can be worked on, but its mostly a natural aspect of their personality.
- Understanding the business side of being a professional photographer.