Guide Number Explained: The Complete Manual Flash Cheat Sheet
What a Guide Number actually means, how distance and aperture fit into it, and why off-camera flash changes the number that matters.
FlashFlash publishes practical articles for photographers who want to calculate flash power before they shoot, especially when working with manual flash on a hot shoe or on a stand.
What a Guide Number actually means, how distance and aperture fit into it, and why off-camera flash changes the number that matters.
A step-by-step workflow for setting flash power from Guide Number, distance, ISO, and aperture when you want to stop guessing and stop chimping.
A practical workflow for handling distance, ISO, aperture, and flash placement when wedding reception moments move too fast for trial-and-error.
A manual flash guide for film shooters who need a dependable starting point because they cannot check the frame on the back of the camera.