Picture this: DSLRs vs Mirrorless Cameras

There’s an old debate still going on in the photography world. Should I go with a DSLR or a Mirrorless camera? There are many options out there with differing feature sets.

First, here’s a breakdown of what the technical terms mean.

Defining DSLR and Mirrorless Cameras

This is how a DSLR works. (Photo: B&H Photo)

DSLR is short for Digital Single Lens Reflex. A DSLR fuses older reflex design with a digital sensor. When using a DSLR, light travels from outside passes through a lens and hits a mirror inside. The mirror then directs the light to the optical viewfinder (the little peephole on the back of the camera), so you can see what you’re about to snap.

However, when you press the shutter button, the mirror flips up, and out of the way (that’s where the reflex comes in), so light can hit the camera’s sensor behind it. That’s how you take pictures.

Mirrorless cameras don’t have mirrors. Light comes through the lens and goes straight to the sensor. The sensor then sends a digital copy of what it sees to an electronic viewfinder (EVF), so you can see your subject. When you press the shutter, there’s no mirror to flip up. The sensor then captures the image. Your smartphone has a digital camera.

This is how a mirrorless camera works. (Photo: B&H Photo)

Size and Weight

One of the most significant advantages of a mirrorless camera is its size and weight. By comparison, DSLRs are often larger and heavier than mirrorless cameras as they must fit a mirror, prism mechanism or extra mirrors inside the body. Mirrorless cameras are generally more compact and more portable.

DSLR bulk does offer some advantages, however. Because they’re larger DSLR cameras may provide a better grip as there’s more camera to hold.

The Canon 1D X Mark III is a massive DSLR camera even without the lens. Conversely, the mirrorless Sony A9 is smaller with similar features.

The Viewfinder

One of the hottest arguments in the DSLR vs Mirrorless debates is whether optical viewfinders are better than electronic viewfinders. As stated before, DSLRs have optical viewfinders (OVF) while mirrorless cameras use electronic viewfinders (EVF).

The viewfinder helps photographers focus on what they want to capture by blocking outside light.

DSLR viewfinders benefit from true-to-life previews.  Light comes from a scene, hits a mirror (or mirrors) and goes into the viewfinder. The image in the OVF will look the same if you should look at your subject directly. The preview will most likely be sharp and helps you compose shots well. However, when you press the shutter button, the mirror inside folds up and blocks the viewfinder. So, for a split second, the OVF will go dark. That’s why you can’t use a DSLRs optical viewfinder while shooting video.

Mirrorless cameras don’t go dark when you press the shutter because there’s no mirror. Instead, the sensor sends a digital picture that is displayed on the EVF. Electronic viewfinders (EVFs) are screens that mimic what the sensor sees.

Because EVFs are digital; the camera can overlay useful information right on the tiny screen.

Unfortunately, some mirrorless cameras have low-resolution EVFs that look blurry when you move, especially in low light.

But most modern electronic viewfinders in mirrorless cameras now, look very good. Some brands now offer high resolution, high refresh rate (doesn’t get blurry as much) electronic viewfinders.

EVFs do have advantages. Because EVFs are digital; the camera can overlay useful information right on the tiny screen. You can know if a part of your image is too bright or too dark before you take the photo.


In times past DSLRs beat mirrorless cameras by miles. DSLRs have a plethora of lens choices as the ecosystem is older and more mature. Mirrorless cameras were stuck with only a few options. However, mirrorless is catching up. Manufacturers like Sony and Panasonic have several mirrorless lenses choices.

If you already have DSLR lenses but want a mirrorless camera, you can get an adapter. These devices sit between a camera and glass and make two seemingly incompatible devices work together.

DSLRs still have the most lens choices.

Other things to consider

  1. Battery Life – DSLRs typically have better battery life as they are more massive. But some mirrorless manufacturers now include larger batteries.
  2. Silent Shutter – Mirrorless cameras can silently take pictures as they don’t have a flicking mirror that makes noise.
  3. Sensor protection – When changing lenses, the mirror in DSLRs protect the sensor from dust or damage. Mirrorless cameras don’t have this, so the sensor can get damaged.

In the end, both are a great option, though mirrorless is the future of photography.