ISO, Shutter speed and aperture

Welcome to the Second part of the learning photography online course. Taking a photograph is like making baking a cake. If you add all the ingredients in the correct amounts you will end up with a great cake. In our case a photograph! However too much of an ingredient can ruin your cake or image.


The three ‘ingredients’ that are used to take great photos are as follows:


The ISO is how sensitive your image sensor is to light. The higher the ISO, the more sensitive the sensor will be, and the brighter the image will be. The lower the ISO, the less light it’s going to bring in, and the darker the image is going to be. If you’re shooting in low-light, you will want to boost your ISO so that the image will be brighter. If you’re shooting in a bright, sunny place, you’ll want to lower your ISO, or the image will be overly-bright. 

But be careful, because the higher the ISO, the more grainy the picture will be. A good max ISO is 1600. If it gets above that, it may be too grainy. You may like the graininess though; it can be used as a kind of artistic effect. Just use your judgement on this. If the image looks bad, try playing around with the ISO and see if you can fix it.



Aperture is the size of the hole in the lenses that opens when a picture is taken. For example when an aperture of F1.4 is used the hole is  open wide  but when an aperture of F8 is used the hole is smaller. Depth Of field is important because the lower the aperture the less of the picture is in focus. Normally the lower the aperture its only the foreground that is in focus. However when an aperture of F8 is used the more of the photo is in focus. Depending on what kind of picture you are taking depending on what aperture you use. When you are trying to take a picture looking along something. With a low aperture of F2 the background of the photograph would be blurred and not in focus. However if the aperture was set at F8 the background and the foreground would be in focus instead of just the foreground with a lower Aperture.


Shutter Speed:

The shutter speed on a camera determines the time the shutter is open for. If the shutter is open for 30 seconds it is letting in a lot of light and if taking a picture of something that is moving it would be blurred. If a shutter speed is lower and a photo is taken of a moving object there wont be any motion blur and the image will be very sharp. If you want to take a crisp clear picture of a sport a shutter speed of 1/125 as it’s the average one to use. However if you want to photograph a moving object that is moving and you want to capture the motion blur you can put the shutter speed on something like 1/30. With a shutter speed you can also create images that show how light moves. For example with a shutter speed of 30 seconds you can stand at the side of the road with cars driving past. After the 30 seconds has past and the picture has taken the image will have light trails. You can do the same process with stars too but would need a much longer shutter speed. When doing this type of photography it is essential to use a tripod as it is virtually impossible to hold your camera still for 30 seconds. Shutter Speeds from around 1/4 to 1/4000.