Wedding photography requires a certain set of equipment to ensure that the photos taken are of the highest quality. Professional full-frame cameras are ideal, but if you only have one camera with a crop sensor, there's no reason why you can't shoot a wedding. Wide-angle lenses and fixed lenses are essential, as well as a flash gun for nighttime receptions. Additionally, memory cards, triggers, and camera bags are also important for wedding photographers.
When it comes to starting out as a wedding photographer, it's quite understandable that you don't have the whole arsenal of cameras, lenses, flashes, etc. Often we start with just the basic equipment we have in the bag and a lot of creativity (and for some, a good dose of confidence). A professional full-frame camera is ideal, but if you only have one camera with a crop sensor, there's no reason why you can't shoot a wedding. The main impact of this would be the lenses.
Unless it is a lens with a dedicated crop sensor, a crop sensor only uses a section of the lens, which causes some loss of light and use of the sensor. Newer cameras are equipped with better technology for managing noise, especially in low light. This technology is crucial because, regardless of the season, weddings will always involve low light. The pixel size of images from newer cameras is also usually larger, allowing more space for settings such as cropping. It also allows better enlargements of your printed photographs. Many people call themselves natural light photographers.
There's nothing wrong with that. However, if you want to photograph weddings, I encourage you to keep an open mind and explore the possibility of learning how to use the flash. Weddings, especially nighttime receptions, can be notoriously dark and having a flash gun will do you some good. After more than 14 years as a professional photographer and photographing more than 400 weddings (there may be more than 500 now, honestly I stopped keeping track), I have compiled a list of my ten essentials that any photographer needs to photograph a wedding. Some of the things are very obvious, but there are others that may not occur to you and that have seemed crucial to me when taking literally hundreds of thousands of photographs in the last 14 years of my professional life. I'm a photographer with natural light from start to finish, and if I can take photos in natural light, I will (high ISOs, fast apertures and slow shutter speeds don't scare me), BUT at the same time, if you're shooting weddings, you'll find yourself in very dark situations, so a flash is a must.
I'm a Canon photographer, so I have a 600ex-rt, a 580ex II and a 430e ex-II. I use them both inside and outside the camera. If you're looking for cheap options for flashes, I've heard a lot about them Yonguo YN600-EX-RT II. My Canon 600ex-rt is powerful enough that I can use an umbrella to shoot or bounce and also use it as an off-camera light source for family photos. Fast headlights are small, powerful headlights, but to get the most out of them, you need to be able to get them out of the camera.
If you move a flash away from the camera, you have unlimited options for angles and directions of lighting. I usually store an off-camera flash on a light stand during each reception so that I can move easily and adapt to whatever lighting situation I'm in. The industry standard wireless flash triggers are PocketWizards, but they have some unreliable products and their activators are also expensive. I use these cheap Yonguno triggers and they're amazing; very reliable (I KNOW my flash will fire EVERY TIME) and they're also very affordable. It should be noted that I do not use ETTL with these activators but rather use them only as manual activators (where I control my flash manually).
An additional advantage is that when I take professional photos in the head or in a commercial session where I need lights; I use these same triggers to control my Alien Bee 800. At first I thought “Is a memory card case really essential?” The images you create at a wedding are everything; without them you're going to get into big trouble. I am a firm believer in systems which is why I create systems for everything I do including how I manage memory cards with important data. When I finish a session; I take out the memory cards from the camera and store them in the memory card case which I then store in my pocket. If I go to a store; my memory cards come too. Camera equipment had already been stolen from me and the insurance covered it; but if my memory cards with the customer's images had been stolen; the story would have been different.
They no longer make the memory card covers that I have; and I love them; but the SD card covers look similar and are affordable. If you're shooting weddings; your images are your product. As I said; my equipment has been stolen; but it doesn't matter; what matters is that I have never lost a single image from a session. I recently changed my memory card company when I switched to the EOS R and it was because I wanted to find the most reliable memory card company; and I opted for ProGrade digital SD cards.
If you're just taking pictures; you don't need super-fast cards (although it's still good); but if you're shooting videos you NEED fast memory cards to be able to record in 4k. These are the memory cards that I currently use and not only are they extremely fast; but they have perfect reliability. I trust these small plastic and metal pieces from ProGrade Digital to store and protect my images until I take them home and upload them to my external hard drive. The Think Tank Retrospective series is a favorite of both male and female wedding photographers (learn more about camera bags for women here); with the “30” being the most popular of all.
It's also one of the first third-party lenses that professional wedding photographers take seriously. The super-fast recycling time of 2 seconds; even at full power; of the Nikon SB-910 is especially noteworthy.