Technical how to: Shutter speed, aperture and ISO.

For alot of budding photographers the settings on a camera can be like learning a new language, it certainly was for me. (Thank god for auto) But I've decided to do my best to explain the technicalities of these settings and how they effect the photograph.

So, what is a shutter speed I hear you ask, well let me explain:
The shutter speed is the amount of time the camera holds the shutter open, letting light in.  The longer the shutter is open, the more light reaching the sensor or film. The speed is measured in factions of a second, for example 1/1000 is 1000th of a second, (that's pretty darn fast). The higher the speed number, the less movement blur and the sharper your image. The lower the number (for example 1/30) the more movement you will see in the photo.

Lower speeds are good for:

• Darkened places, as it lets more light in without having to use flash.
• wanting to capture movement in a photo.
• Night-time landscapes (using a tripod, to avoid camera shake)

Higher shutter speeds are good for:

• Capturing sharp movements. 
• When there is alot of natural lighting. 
• Portraits (as you don't have to worry about making your model stand still for long!)

Slow Shutter speed. Notice the movement blur.

High Shutter speed. Sharp action shot. 

Below is an example of an EXTREMELY slow shutter, probably over a few hours to catch the stars movement. 

Onto the Aperture...

What does it do?

The aperture is also responsible for controlling the amount of light let into the lens (I'll explain how shutter and aperture can be used to get the correct exposure for your photo). This is were it can get a little tricky to understand, but bare with me. The aperture controls the size of the hole that helps you capture the image. Aperture is measured in F stops and the smaller the number for example F/2.8, the smaller the hole. Although the number is small, it actually means MORE  light is let in. So remember:

'The smaller the F-stop, the more light.' 

That isn't apertures only use though, its also responsible for controlling the depth of field. Oh no, not another confusing term, but sadly it is quite an important aspect to getting the photo you want. 

The depth of field is simply how much of the photo is in focus. A shallow depth of field means that only one thing may be in focus, and the background is blurry. The smaller the F stop, the shallower the depth of field. F/2.8 is shallow, however F/16 is wide and mostly everything will be in focus. 

Shallow depth of field is good for:

• Macro shots.
• Still life or product photography
• when photographing in low light. 

Wide depth of field is good for:

• Landscape photography 
• photographing a large group of people.
• When photographing in bright light. 

Shallow depth of field

Wide depth of field. 

Bear in mind that using a shallow depth of field will let more light in then using a higher number. Which is where the shutter speed comes into play. Working the shutter and aperture together to get the correct exposure can be difficult, but the more you understand how they both work, the easier it will be, trust me. 

So lets say if you wanted an extremely sharp photo of someone running, you would have to use a high shutter speed, say 1/600th  of a second. Because that's quite a high speed, it wouldn't let that much light in, so the photo could be underexposed. To compensate for this, the F-stop needs to let more light in, by using a smaller F/stop, like F/4. This is just an example as every lighting condition is different so you would need to play around but you can see how the two aspects work together to get the correct exposure. 

ISO

The ISO used to be the sensitively of light on the film but now days in digital photography it measure the sensitively of light on the sensor. So effectively it is another way to control the light. Don't panic though, this one is simpler to understand and doesn't effect the image as much as the shutter and aperture. The higher the ISO number, the lighter the image, but this does come with a down fall, the photograph will be more gainy. A lower number like 100 ISO will produce a nice crisp image but slightly darker, you can fix this if the lighting is good by Shutter and aperture. 

I wouldn't worry too much about the ISO but below is a list of times you may need  a higher ISO:

• Photographing a gig or event with low lighting. 
• Photographing at night. 
• 'No-flash' zones, like certain parts of a wedding. 

Below is a photo of were these things are displayed on my Canon 60D but every camera is different so check your manual.