Recently i wrote a blog on the concept of f/stop (see my other f/stop blog) and asked people what they thought…. the feedback told me that the blog was a bit too heavy, too much detail and a bit of a tough read especially for photography beginners…. i took this on board and have now wrote a new blog below.

The old, more detailed one is still available for reference.

So what is f/stop….?

If you are new to photography you may have come across the term f/stop, but not really sure what it is or why you need to know… well here is my best attempt at a short, simple overview to give you the basics.

In my opinion photography requires two main skills : A creative eye and the technical ability to operate the tools… f/stop falls into the technical bit..

To create an image in your camera, you are basically managing how the light passes through your camera lens (aperture), passing the shutter (shutter speed) and falling onto the camera sensor (ISO). By making adjustments to these camera components, one can determine how the image will look… for this blog we will ignore shutter speed and ISO and just concentrate on APERTURE.

f/stop is a term relating to a standard way one can increase or decrease the amount of light falling onto your camera sensor…. changing your camera settings by one full stop, will halve or double the amount of light….. Just pause on that thought and repeat it… one full stop of camera adjustment will halve or double the amount of light exposing your camera sensor….

If you can just remember this you are making good progress… honest..

So, you sort of understand, but still not sure what i mean by a FULL STOP….you want a practical example……

Right then… for the purpose of this simpler guide, we shall look at just one way to make a full f/stop adjustment…. you can do this by modifying the LENS APERTURE… that is the adjustable hole in the lens where the light enters…..

If we look at the pic of the lens above can you see those numbers on the bottom of the Lens : 1.4, 2, 2.8, 4 etc……… these are the aperture settings on your camera lens.. changing these settings will change the size of the hole in the lens and determine how much light gets in…….

An aperture setting at 1.4 would represent a large hole in the lens, letting in lots of light. If we change this setting to 2.0, this would make the hole a little smaller and let less light into the lens. This step change is regarded as ONE FULL STOP and this will HALVE the amount of light entering your lens. If we did it again and change the setting to 2.8 you would make the hole smaller again and HALVE the amount of light again…. you get the idea….

Therefore, in really simple terms…. a setting at 1.4 will be a big hole (aperture) letting in lots of light…. whereas a setting at 16 will be a small hole (aperture) letting in only a little light….

The aperture in the lens looks something like this…


SMALL number (like 1.4) equals BIG hole equals LOTS of light

BIG number (like 16) equals SMALL hole equals LITTLE light

ONE FULL STOP adjustment (up or down) will HALVE or DOUBLE the light entering your camera

If you would like to know more detail, check out the detailed f/stop blog..