Aperture vs F-Stop
When it comes to photography, there are many jargons used that might seem overwhelming to a beginner. Aperture and F-stop are among these two terms. What’s more confusing is that many people use these two terms interchangeably. Technically, aperture is the size of the hole that lets light in. In cameras, this is the diameter to which your diaphragm opens up to. A small diameter diaphragm opening lets little light in and a bigger would correspondingly let more light in. In comparison, the F-stop is simply a scale that correlates the aperture to the focal length of the lens. So a longer lens can have a bigger aperture while a shorter lens can have a smaller aperture, yet they would be at the same F-stop.
The main reason why F-stop is prevalent in photography is the scaling. It is a fact that every time you increase one step on the F-stop, you are halving the amount of light that enters the sensor. Aperture sizes are not scaled in the same manner so you have no idea of how much light is actually entering your sensor.
In actual photography, it is the F-stop that is commonly used rather than the actual aperture of the lens. The amount of light is the most important aspect in photography as too little results in an underexposed photo while too much, results in an overexposed photo. In cases where you want to limit or expand focus of the subject by adjusting the size of the aperture, choosing a higher or lower F-stop would achieve the same result. Correct exposure is still achieved by adjusting the shutter speed. A faster shutter speed compensates for a bigger aperture while a slower shutter speed compensates for a smaller aperture. Although the latter is susceptible to blurring, especially when the camera is not mounted in a fixed position.
These two terms, as I’ve said, are used interchangeably and there is nothing wrong with that; most of the time they are referring to the same thing. Just keep in mind that these two have an inverse relationship. As the F-stop value goes up, the aperture size goes down.
Summary:
1. Aperture is the opening that lets light in while F-stop is a scale that relates the aperture to the focal length
2. Aperture sizes aren’t scaled while F-stops are
3. F-stop is more useful in photography than aperture
4. F-stop and aperture are inversely proportional