Crop factors caused by different sizes of sensors in different cameras still confuses a lot of people. Mostly because there’s so much bad information out there and a lot of the explanations about how sensor size affects your image either try to simplify things too much or they get overly confusing, making the situation worse.
Well, filmmaker Daniel Scott Murphy is trying to help you understand them with his new crop factor calculator. There are a few of these out there already, but this one actually offers a visual indication of the crop, simulating the results with a real image. It can even take speed booster lens adapters into account.