Nothing rude – but the one topic that keeps cropping up (no pun intended) on our courses is f-stop, a.k.a. aperture.
Basically, the aperture or f-stop is a numerical value representing the size of the hole that light travels through the camera lens before reaching the image sensor or film. The bigger the hole, the more light – the smaller the hole, less light. The bit that throws people is the number itself. The confusion arises mainly because the bigger the f-stop number, the smaller the hole, and vice versa – the smaller the f-stop number, the bigger the hole.
Don’t get hung up on what the number means – it’s all a bit mathematical – just remember:
- bigger hole=more light=smaller f-stop number
- smaller hole=less light=larger f-stop number
Each time the amount of light doubles or halves, is known as one full stop – the common full stop values you’re likely to come across are:
And so on – each one in the sequence above being one full stop. Pretty much all cameras out there today offer fractions of a stop too – at least half stops, many thirds of a stop.
So why not just set your camera on the biggest aperture (smallest number remember) and get as much light as possible into the camera through the lens? Well this is where you get to control depth of field (see an earlier post) – have a look at the two images below:
Controlling the depth of field in your images is one of the greatest creative controls available to you and is covered on our Getting Started with Digital Photography course.