Number or digital cameras and lenses you need is n+1, where n is the number of cameras you already have. ;)You can support my work buying anything from Amazon by using these links below before shopping. You will not pay more than otherwise, but I get a small percentage from every purchase.Amazon USA: http://amzn.to/1MrBiCQAmazon UK: http://goo.gl/WdQ5rNAmazon Canada: http://goo.gl/8FjrKqAmazon Deutschland: http://goo.gl/jCMDsNAmazon India: http://amzn.to/2oEcNfC