I often hear, "You should only pick your wedding photographer if they use a particular brand of camera/lens and use full format." - Usually Canon or Nikon. Let's dispel one myth straight away, there is no such thing as full format! There's full frame, medium format, crop format and micro four thirds format.
Full frame is equivalent to the 35mm film format, medium format historically refers to the 120 size film format that was used in the Hasselblad V System cameras. In digital photography, medium format refers either to cameras adapted from medium format film models or to cameras making use of sensors larger than that of a 35mm film format.
Crop format usually refers to a smaller sensor than full frame and usually has a crop factor of x1.5 in the case of Sony, Nikon and Fuji crop sensor cameras and x1.3 or x1.6 crop in the case of Canon crop sensor cameras. So the lenses used are 1.3, 1.5 and 1.6 times the focal length in use. For example a 70-200mm lens on a Canon 1.3 crop body would equate to 91-260mm.
In March 2014, I was introduced to the Micro four thirds mirrorless system which was developed jointly by Olympus and Panasonic and are the only two companies that make the system. The advantage is all their lenses are compatible across the two brands.
Micro four thirds is x2 crop factor, effectively doubling the focal length of micro four third lenses - see below for more explanation. Panasonic cameras and lenses are branded as Lumix.
In the case of some lenses, they're branded as Lumix Leica, as the two companies are in partnership with certain lenses.
Leica lenses are synonymous with superb quality and very sharp images. Having said that, all the lenses I use are capable of producing high quality images, which at the end of the day is what you're paying for.
This system is smaller and lighter than the Canon kit I was using at the time but with equally good image quality especially when using professional lenses from Panasonic, Olympus and Sigma.
I dipped my toe into the micro four thirds system but kept my Canon kit at the same time. However, in November 2016, I finally took the plunge and now exclusively use that system and for my professional work, I use the following kit:
Three Lumix G9 cameras with any of the following lenses: Leica 12mm, Lumix 12-35mm, Leica 25mm, Leica 42.5mm and a Lumix 35-100mm- 35mm (think of film days) equivalent of 24mm, 24-70mm, 50mm, 85mm and 70-200mm respectively. All have a wide aperture, capable of throwing the background out of focus to make the subject stand out.
The 35-100mm lens is perfect for if I'm stuck at the back of the venue as I can get close without "getting in yer face" so to speak.
The 12mm and 12-35mm lenses are perfect for small to large group shots and for taking in the whole of the venue at the 12mm end of the 12-35. The 12mm is perfect for taking in the whole of the dance floor for the first dance, an excellent low light lens.
The 42.5mm lens is the ultimate head and shoulder portrait lens which gives beautiful bokeh - this is a Japanese word meaning out of focus. The background will be beautifully out of focus and the main subject will be pin sharp, making you really pop out of the background.
The 12mm and 42.5mm lenses are known as prime lenses which are sharper than their zoom counterparts but I can still zoom, only with my feet.
Then I have a Panasonic Leica 100-400mm lens with a 35mm equivalent of 200-800mm and I could literally stand across the road in the car park with this lens attached to one of my G9's and still get a shot of you signing the register!
The G9 camera bodies are dust, splash and freeze proof down to -10. The 12mm, 12-35mm, 35-100mm and 100-400mm lenses are all weather sealed.
So if you're having a winter wedding, you can be safe in the knowledge that my cameras/lenses will keep going when your friend or friend of a friend with the entry level/cheap camera/lens will be running for cover.
My G9 cameras have dual memory card slots and I always save to both cards and I also have numerous high capacity memory cards, batteries and three flashguns, although I tend to prefer natural light as flash can spoil the ambient light and the ambience. However, I will use the flashguns during the evening reception and usually off camera using a remote trigger to give more pleasing light than on camera flash.
I also have a Lumix GX9 camera with a Lumix 14-140mm lens, 35mm equivalent of 28-280mm. If I absolutely had to, I could use this combination to shoot an entire wedding. This kit is usually reserved for my personal/street work and is always in my car as a backup for my wedding kit.
As you can see, every eventuality is covered with my extensive camera kit and this is something to consider when hiring an amateur photographer to shoot the most important day of your life. Will they have this amount of backup? You only get one chance to photograph a wedding so why leave it to chance by hiring an amateur?
If my images have a "blurry background" this is done entirely for artistic reasons such as the image of the bride and flower shot and the groom in the mirror. This is one of the benefits of having a lens with a fast aperture.
The same goes if I cut heads off, this is done on purpose to emphasise a particular detail such as the bouquet shot below.
I offer the services of a second photographer as an extra backup and to cover your wedding from different perspectives, something your friend or friend of a friend wouldn't even consider.