One little nit is the acceptable shutter speed for a given lens focal length depends _heavily_ on the camera and shutter type being used! In the past, 1/focal

One little nit is the acceptable shutter speed for a given lens focal length depends _heavily_ on the camera and shutter type being used! In the past, 1/focal length was perfect advice. You can adjust this down very quite far if you have a lens or body with image stabilization, typically down to as far as 1/30 or even lower. Also bodies get higher resolution, the amount of blur you can see goes up as well as you start sampling higher frequency movements of the camera body. You probably need 1/2 x focal length above 24MP, unless you have stabilization. There are also different types of shutters, for example a leaf shutter in the lens vs. a focal plane shutter. Focal plane shutters can inject some shutter shock at lower speeds, where as leaf shutters don't have this effect and can be handheld to much lower speeds, I have gotten very sharp shots as low as 1/8th. Finally, if your camera has a mirror or not also effects this, as the mirror swing imparts vibration as well. Knowing exactly how the camera reacts at different speeds will let you tweak this rule a lot!