By March 25, 2013 6 Comments

What Is a Mirrorless Camera?

This video blog post explains the basics of mirrorless cameras, and it’s meant for beginners and people who don’t know how they differ from dSLR cameras.

My students asked me recently: What’s the difference between dSLR and mirrorless cameras?

In simple terms a dSLR has a mirror and a mirrorless camera doesn’t.

But why is there a mirror in the dSLR in the first place?

The mirror allows us to see through the lens when composing our photos. The light then bounces up into a prism on the top of the camera and flips it the right way up and the right way around.

SLR light paths. One bouncing up through the prism and one going straight through when the mirror is up.

If the mirror wasn’t there, the view through the lens would be upside down and backwards, just like a good ole view camera. (And yes, I have used a view camera.)

When you press the shutter on a dSLR, the mirror flips up out of the way and the light is then able to travel to the back of the camera where it reaches the sensor (or film if you’re using a film SLR).

So how come we see the photo the right way around on a mirrorless camera?

EVF and LCD Viewfinders on the Lumix GH3

On a mirrorless camera you compose your photos using the LCD screen on the back of the camera, or an electronic view finder with an eyepiece (EVF). Some cameras have a rangefinder. A rangefinder has an eyepiece viewfinder that is close to the lens, like for example, on a Leica camera.

With these other types of viewfinders, the mirror and prism are not necessary.

This makes mirrorless cameras much quieter too, because you don’t have that clanking of the mirror every time you take a shot. And that’s great for things like wedding ceremonies, when you need to be super quiet.

By the way: Mirrorless cameras are not new.

Leica with the rangefinder circled

Rangefinder cameras have been around for many years. The film version of a Leica is a rangefinder too, and there are many others.

The new features with digital mirrorless cameras, are the EVF and the LCD viewfinders.

P.S. If you want more technical info about mirrorless cameras, check out this article on Wikipedia.

About the Author:

With over 20 years as a pro shooting editorial, sports, corporate and industrial photography, Marlene Hielema has become comfortable with the craft of digital output. As a photo and video tinkerer and troubleshooter, Marlene enjoys relaying the practical uses of photo and video hardware and software that you might not find on the manufacturer's or software publisher's websites. Thousands have seen her work on YouTube and her popular site where Marlene teaches photography and photo editing online, in the classroom, and one-to-one. Find out more about what Marlene can help you with here on discovermirrorless, as well as and

6 Comments on "What Is a Mirrorless Camera?"

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  1. Kidamadge says:

    I bought a G10 a couple years ago and then my eyes changed and needed bifocals. Now I can’t use the EVF, as I can’t focus properly.

    It’s very disappointing.

    I can use a DSLR just fine, btw.

  2. Steven Lynch says:

    What exactly is the problem here? The G10 has a magnification 4 diopter adjustment. Physically it is the same as using an SLR with the image being projected onto a viewing screen within your vision. Just curious what the issue is.

    I know I’ve had some issues before as well, but I wear glasses. My vision is distance issues not up-close though so I don’t share the same issue there.

    Thanks for sharing!

  3. Really Kidamadge? I have progressive (bifocal) eyeglasses and I don’t have any problems with the dSLR, EVF or LCD viewfinders. And I got progressive lenses because I couldn’t see the LCD on the camera, or see well enough to read magazines and books anymore. I was worried I’d have problems focusing with the new glasses so I procrastinated, but in the end my fears were unfounded. Ah the joys of aging.

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