What is a lens hood – Part 1 (Flare and Contrast loss)

Do you wear a baseball hat when it’s sunny? See people who do? Do you wonder why people wear them? A lot of people wear baseball hats to shade their eyes from the sun. So what does this have to do with photography? Since photography is all about light, you want to make sure the light hitting your lens is the light you want.

What is this extra plastic in the box?

So you got some piece of plastic ring thing with your lens and you’re not sure what it’s for. Well, that’s your lens hood and it serves a few uses. This post will cover only one of the uses, reducing flare and contrast loss.

Why, Contrast-loss

The front of your lens is susceptible to stray light which may cause your photo to have dull colors. A lens hoods serve as a circular shade to block that light. Sometimes the hood isn’t long enough and some lights peek through and do affect your photo.

Below are two photos taken seconds apart. One with the lens hood in place and the other without. Image 1 has a sort of lighter tint and some blueing above the book. Image 2 has the lens hood in place and stopped the light from hitting front of the lens. This is an example of contrast loss.

Image 1 - No lens hood

Image 2 - With lens hood

To create this minor contrast loss, I aimed a flashlight straight at the front of the lens above and in front the camera as seen in Image 3.

Image 3 - Camera and Flashlight

Image 4 below shows extensive contrast loss outside due to the sun hitting the front of the lens.

Image 4 - Contrast loss due to the sun

Why, Flare

While outside on a bright sunny day it’s very easy to get flare from the sun (in addition to loosing contrast). Image 5 shows flare from the sun in the bottom left of the photo. Sometimes this type of flare desired. What are your thoughts?

Image 5 - Sun Flare

More

In addition to flare prevention, the lens hood carries additional duties which will be explained in another post.

  1. the clubhouse kid’s avatar

    Lovely post, nothing like a couple examples to visualize things (I for one, never thought of using the hood inside).

    About desired flare, a post on that would be great too!
    I can get some pretty flare from my cheap 28mm Tamron, but none from my G 50mm. 🙂

  2. WhatsWrongPhoto’s avatar

    Thanks for the comment. Yes, visualization is the name of the game here! 🙂 I also learn by viewing real world examples.

    Good idea about desired flare. I’ll add that to the list!

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