Exposure Triangle

By May 1, 2015Photography Tips

In future posts I’ll be going into more details about Shutter Speed, Aperture and ISO but I wanted to highlight the high level impact that these setting have artistically and with exposure. This is known as the exposure triangle because each of these 3 setting are responsible for exposure in your camera. Photography is all about tradeoffs and the best way to figure out these tradeoffs is to shoot in manual mode.

Here is an example. Let’s say that you want to shoot an aperture of 4 because you had read that your camera’s lens is sharpest at that setting. Your goal is to shoot at the Lowest ISO possible to minimize graininess. In a medium to low light situation your shutter speed is going to have to be slow. Which will cause less sharp images due to shakiness. In order to get a good photo you’ll either have to make a compromise with the ISO by increasing it and thus the graininess or you will have to widen the aperture to something like 2 or 2.8. When choosing settings for artistic reasons, understanding the exposure triangle will allow you to know where to make compromises when trying to achieve proper exposure.

Photography Exposure Triangle

Shutter Speed

Shutter speed is the measure of time that a camera’s shutter opens and closes. Essentially how long your camera’s sensor or film is exposed to light. The longer the shutter is open the more light hits the sensor.

Fast Shutter Speed

Diving Hawk

Lens: 70-200mm 2.8 w/ 2x extender, Focal Length: 400mm, Aperture: f/5.6, ISO: 100, Shutter Speed: 1/1000 sec

Exposure Impact-Less Light

The shorter the shutter is open the less light hits the sensor.

 Artistic Impact-Stop motion

Sports photographers and wildlife photographers are well known for using fast shutter speeds to freeze the motion of the fast moving subjects they are shooting. Faster shutter speeds can help you create sharper images because they increase the likelihood that your image will be in focus. Increasing the shutter speed is a simple fix for images that have too much camera shake.

Slow Shutter Speed

Long Exposure Example in Moab

Exposure Impact-More light

Slower shutter speeds allow more light to hit the camera sensor.

Artistic Impact-Motion blur

Slow shutter speeds create blur if any object in the image is moving. In general, this has a negative impact on the image. There are some artistic applications for slow shutter speeds. Long exposures can be really cool when done right. It’s important to use a tripod if you are using very slow shutter speeds.

Aperture

Aperture is the opening in a lens that light passes through. Aperture is measured with an f/ in front of the number. The number represents the ratio of the lens’ focal length to the diameter of the opening. I’ve seen these ranges from 1.0 to 22.

Wide, Fast, Low F Aperture

wide aperture example

Exposure Impact-More Light

Wider apertures mean that the diameter of the opening is large, allowing more light to pass through the lens to the sensor.

Artistic Impact-Blurred Background

Wide apertures create a shallow depth of field. Translating to human speak, it creates blurry backgrounds. This is something that’s often highly desired amongst fashion photographers because they draw the attention to the model. Wide apertures also increase vignetting.

Narrow, Slow, High F Aperture

Sunset picture

Exposure Impact-Less Light

As you start to narrow your aperture by increasing the F number, less light makes it to the sensor.

Artistic Impact-Wide Depth of Field

Narrow apertures create a wide depth of field. This is great for landscape photography where focus points in the foreground are just as important as items in the background.

ISO

ISO is the measure of sensitivity of your camera’s sensor or film. Most digital cameras have ISO ranges from 100 to at least 6400.

Low ISO

Exumas beach sand

Exposure Impact-Less Light

By reducing the sensors sensitivity to light the sensor actually takes in less light.

Artistic Impact-Low Noise (Grain)

Low ISO numbers give cleaner, crisper images.

High ISO

high ISO grain example

Exposure Impact-More Light

Increasing your ISO number makes the sensor more sensitive to light. This actually increases the exposure because it’s less concerned with detail but rather it’s just identifying light.

Artistic Impact-High Noise (Grain)

High ISO numbers introduce graininess into photos. This can be used for artistic purposes. Modern technology has greatly improved noise reduction at higher ISO settings.

8 Comments

  • Gabriella says:

    Hi Thomas,

    Thank you for this informative post! Could you maybe add the info about which settings you used to all the photos? (Like you did with the first). That would help a lot more with understanding what you’re talking about! Thanks again for the post!

    – Gabriella

  • Katie Stuart says:

    This was SO helpful!! I think I was getting confused between the ISO & aperture and actually haven’t been paying attention to the aperture at all. Looking forward to more posts like this!

    Katie
    allglammedupstyle.com

  • Haley Mason says:

    Hi Thomas,
    thnak you so much for the Post, it was really helpfull. I’m still struggeling to get perfect Pictures, or let me say that my mother do great shots haha.
    I understand a little bit about photography I’m interested in it and want to learn as much as i can about it, but it is hard to pass the informatuon to someone (my mon) who takes the picutres.
    I’ll sent my mom this article maybe she is going to understand a little bit more about what i’m trying to explain her weekly haha.
    I really would love to see a blog post about editing Instagram pictures, I’ve recognized that all Picutres Julia post on her instagram aren’t the original one they are edit with some filter and i think they look so beautiful, would love to see a post about that too.

    best wishes Haley

  • Joanna says:

    Thomas, you are amazing! Where have you been all my life, you are a great teacher. Photography is becoming a favorite hobby of mine and this post is just what I needed. Thank you:)

  • Cameron says:

    This is wonderful information! I’m new to photography and am trying to comprehend all of the technical information which you explain well. Looking forward to more posts!

    Canon 7D,50mm/2.8

  • Ashlee Neff says:

    I have been reading your posts, and this post and the photography glossary were extremely helpful. I just got my first DSLR for Christmas, so your information has been very useful to me and my understanding of how my camera works and how to take better pictures! Thank you!

  • Lauren says:

    Thanks for these photography posts – you explain so clearly!

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