In this video I break down something that sounds super technical, but is actually pretty simple: how to calculate your camera’s crop factor from the sensor size. A lot of people know what “1.5x” or “1.6x” means in practice, but not how that number is derived. This whole topic came up because I posted about the Canon C70 and the 0.71x adapter (speed booster), and someone corrected me with the usual “Canon crop is 1.6x.” That’s true for Canon APS-C, but the C70 is Super 35, and I wanted to show exactly how I know it’s closer to 1.5x—by doing the math. I use the Pythagorean theorem to find the diagonal of a sensor (the “c” in a² + b² = c²). Full frame is a constant (36mm x 24mm), so once you calculate its diagonal (43.27mm), you divide that by the diagonal of whatever sensor you’re using. I run through real examples: Canon C70, Canon APS-C, Fuji APS-C, and even medium format sensors (and a big RB67 negative) to show how crop factor changes across formats. My bigger point is simple: photography is art, but you still need to know your tools—numbers help you work faster, make better decisions, and get the look you’re after.