Understanding Exposure

I call it the Bermuda Triangle of photography, it is where everyone gets lost… understanding the relationship between ISO, Aperture and Shutter Speed will help you take better photo’s. If you have a camera that has a manual mode and you use it on auto, you have wasted your money!

So here’s a quick run down, this is part 1 of a multi-part series… 

Your digital camera uses a sensor to record an image. For this to happen a certain amount of light has to be let through the lens and onto the sensor to create the perfect exposure, too much light and your image will be over exposed (too light/bright), not enough light and it will be under exposed (too dark)… when your camera is on auto, it makes a bunch of decisions on your behalf and decides the ISO, Aperture and Shutter speed for  what it thinks is going to be the best exposure, or, if you have a ‘scene’ mode it will be biased in how it makes those decisions in favour of the scene you have pre-selected.

Once you understand how ISO, Aperture and Shutter speed effects your final image, you can make these creative decisions for yourself. Here is a brief run down of the 3 points of the triangle…

ISO – this is the sensitivity of your sensor, the higher the number, the more sensitive it is, meaning it captures the light quicker… the downside to this is what is called “noise”, you might relate to this as ‘grain’ in your image.

Aperture – this is the amount of light you are letting in though your lens, also known as the ‘f’ number. It is also how you control ‘depth of field’, the amount of your image than is in focus in front and behind your focal point.

Shutter Speed – this is how long your sensor is gathering light, the shutter blocks light from reaching the sensor, and can be open for a fraction of second or several minutes depending on what you’re trying to achieve.

Tomorrow we will look at exposure in more depth, and I am going to give you a simple way to understand how it all works… stay tuned!

The Daily Pic – Rock Pool

I took this at Avalon Beach. Any time I see a pool of water I like to see if I can capture the reflections… this was so clear you could see all the detail in the bottom of the pool… I also like to be able to explore different compositions and perspectives to keep it interesting… enjoy!

Avalon Beach Rock Pool

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