What do people do when it comes to backup lenses? I'm thinking lenses specifically, and in-particular people who are doing paid work. Reason for the question is I have recently done some product and other general photography for my sister in law's small business, some of her suppliers who are also quite small local suppliers apparently like what I've done and may want me to do some bits for them too. But this raised the question for me as when I was doing my sister in law's stuff I wasn't overly concerned about things failing as I wasn't being paid, nor was it high pressure or time sensitive. But if I'm doing it for someone else and potentially in their environment, even if I'm not doing it in a professional capacity they'll no doubt expect that of me so it is something for me to consider. (I'd rather not get into the professional, contract, charging debate in this thread if it can be helped, I've read enough threads in the business section to understand the issues here!) I'm not after advice on my situation, more wondering what peoples strategies are, the higher stress the more important this is to consider so, for instance you wedding shooters: If you use mainly primes say 35, 85 and 135, do you all have the usual two zooms (24-70 & 70-200) in the bag just in-case one of your primes fails or gets broken? Do these have to be f/2.8 versions for you if they are getting hardly any use? If one of your zooms fails, do you just switch to a prime within that range and make do? Do you have a selection of say 6 primes and if one fails, just accept it and use the others? I'd be interested to know how you guys deal with this whatever it is you shoot?