Epstein Studio Photography Tip #4- F-stop – Lens opening – the last leg of the exposure triangle

In our last tip we discussed, shutter speed. The amount of time the shutter is open to let in light. This time we are looking at our diaphragm or F-stop(aperture). This is the amount of light the lens lets in during the exposure. The quantity of light is controlled by a variable diaphragm that widens and narrows to help create the correct exposure. Since the F-stop controls the amount of light, by using an F-stop that allows a lot of light in, this gives us the opportunity to use a faster shutter speed. Conversely, if we want an aperture that greatly limits the amount of light, we will have to adjust one of the other legs of the triangle to maintain a proper exposure. Here is a chart of different F-stop openings:


Read the explanation of how the F-stop naming is determined and its relationship to shutter speed. The F-stop also controls the apparent depth of field (what is in focus) of your image.

We have now completed our exposure triangle- ISO (film speed, sensor sensitivity), shutter speed (time shutter is open) and aperture (F-stop, amount of light that hits the sensor)

To learn more about this exposure triangle and how you can control all 3 to get the image you want, come to one of my classes. Email for the latest schedule!

For the next tip which will come up very soon, I will show you the Exposure Triangle and how it works!!