This is a very common question that is asked by those who want to get a better flash than the one they already have. Put simply the Guide Number is the output of the flash that can be used to find out the f-stop to be dialed into the camera when the flash distance is known. The trick is to divide the Guide Number (GN) by the distance (in feet) and the answer is the f-stop you … [Read more...] about What is a Guide Number and How do I use it
We know that there are two types of exposure meters for measuring light that the camera uses. One is reflected and the other is incident. What does this mean and how do you use both? The type that is in most cameras is a reflected kind. Incident is the meter that has a dome on it and this dome is pointed to where the camera is. The reflected meter is pointed at the subject to … [Read more...] about What is meant by 18% gray and how is that number arrived and why?