Event photography, the joyous pursuit of photographing, say, a black-tie dinner and selling the prints to the guests.
It can be an enjoyable way to spend an evening and make a living, when it all works as it should.
When it doesn't then it can be stressful and hard work.
That's when you need to get your backup.
It's always a good idea to have backups/spares for all your major pieces of equipment such as the cameras, compact flash cards for storing the images on.
A backup computer in case of a crash, spare leads such as power cables, network cables or leads for the camera.
The problem with this is that you have to carry all that extra equipment with you and you have the initial expense of that equipment too.
There are certain pieces of equipment that you must have, the camera for instance, if your camera packs up and you can't even take photos then you may as well go home.
Lighting equipment as well, if possible carry a spare flash head and at least carry spare flash bulbs and modelling lights if you use studio flash.
It's not always practical to have spares for everything, the dye sublimation printers that are used in modern day event photography are heavy and expensive to purchase.
Wireless units for transferring the images from the camera are also expensive.
If you decide to not have a backup of a particular piece of equipment then you will need an alternative method in case of failure, in theatrical terms this is called an "out", a way out of the problem.
If a magicians trick goes wrong you'll never know because the magician will have an out, he'll have practised it as well so it will appear that it's just part of the trick.
As an event photographer you'll need the same for any possible problems where you can't just slot in a piece of new equipment.
If the wireless unit doesn't work because of failure or interference then you need to get the images from the camera to the central computer, maybe by using a card reader and swapping the cards in your camera every few shots so they can be uploaded to the computer manually by your assistant.
Or by tethering your camera to the computer via a lead.
Whatever method you choose you'll need to know how you're going to achieve it, have the relevant equipment ready and you should have tested this procedure as well beforehand so that it's second nature.
Examine your workflow and ask yourself this question, "if that piece of kit fails, can I still carry on with the job?" if the answer is "no" then you need to figure out what you're going to do in advance.
Either a spare piece of equipment or an "out".
Trust me, the last thing you want is to be trying to figure this out when you're at an event and you have a queue of people starring at you or worst still walking away while you stare into space looking for inspiration.
Get ready, be prepared.