The different kind of viewing systems

Electronic viewfinder, DSLR, LCD… Learn more about the different viewing systems you can find in a camera

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Camera overview

Digital Single Lens Reflex (DSLR) viewing system

Let’s talk about Single Lens Reflex cameras. We’ll talk about them first because they have been for close to 60 years the most popular choice for enthusiast and professional photographer.

How do they work? The light comes through the lens on your camera to a mirror system. Then the light bounces up to a focusing screen and then up through a prism system to the viewfinder. In other terms, with this system, you get to see exactly what the lens sees. It’s good for many reasons like for focusing, or simply to see if you’ve left the lens cap on your camera. It’s really nice to be able to see exactly what your camera sees through the lens. However, when you press the button, the mirror does need to get up for taking the photo and for a short period you won’t see what’s going on. Afterward, the mirror comes down when it’s all done, and you get to see again.


DSLR Camera Viewing System

The main advantage to the SLR is the incredibly sharp viewing. If you want to focus your camera manually, this is an excellent system to use. It works very well because you get to use your own eyes, which is especially useful under low light and high contrast situations. They also have an excellent autofocus system. We’ll talk more about autofocus system as we go forward but here is an article about differences between “manual focus vs autofocus.”

Now the downside to this system is that the mirror housing causes the camera to be a little bit larger than it might necessarily need to be. There are also vibrations caused by that mirror moving up and down. Moreover, the image you’re looking at is only a preview – you’re looking at it with your own eyes – and it’s not the final digital version. Indeed, all the settings of your camera impacting the final result won’t show up before you check the back of the camera. In other words, you have to check to see if you got it the way you thought you got it.

Despite those disadvantages, DSLR is a very, very popular system.


LCD viewing system

LCD is what you’re going to find on your everyday point-and-shoot camera. We can throw our phones, tablets and any other device like that into this category.

Because it does also have just a single lens on it, the light comes in through this lens and go straight to the sensor. Then the information is sent to the screen on the back of the camera.

LCD Camera viewing system

One advantage is that with this system you can use two eyes to compose your picture instead of just one through a viewfinder.

However, as I’m sure all of you know, that LCD does not work well in bright light conditions. In fact, I don’t like relying on them even on a cloudy day, because you don’t get a really good look on those small screens. It’s hard to see sharpness and color, and you could be shooting all day long missing the fact that some of your pictures are out of focus. You would never know unless you start zooming in to check your images individually.

So, just having an LCD is definitely a disadvantage for me. In general, a lot of these cameras also have a lower resolution. Moreover, they often have limited controls because there’s not enough room for all the buttons and controls that somebody who’s serious about photography would like to have.


  • Small size
  • Easy to use with both eyes
  • POV possibilities


  • Hard to use in bright light
  • Low resolution
  • Limited controls

EVF: Electronic ViewFinder

These cameras work a bit like the SLRs; indeed, they have interchangeable lenses for the most part. Light comes in through the lens, to the sensor like the point-and-shoots and you get to see what the lens sees, but it also sends the information to the electronic viewfinder.  An electronic viewfinder is excellent because now you can work with the camera under very bright light conditions. No matter how bright the light is, put your eye up to the viewfinder, and you can see exactly what you’re going to be shooting. Indeed, with the live preview on the electronic viewfinder “what you see is what you get.” If you messed up WB, Saturation or Contrast, you can see it live!

EVF Camera viewing system

At the moment the main disadvantage is that they have a refresh lag. No matter how fast they are, they still aren’t as fast as the way we see images with our own eyes. They also tend to have a lower dynamic range. Indeed, think of being in the forest with bright sunlight coming in. It’s tough for them to show you the shadow and the bright areas at precisely the same time. Moreover, they also do use more power, and if you plan a trip away from electricity and charging units, you’re going to need more batteries.

On the other hand, there are lots of advantages. First one, you get to see exactly what the lens sees. Like I said before “what you see is what you get.” You get to look at the final image before it is final. You get to see the exposure, the depth of field, the point in focus (focus peaking) and many other parameters. That’s not something you get to see with an SLR camera. Simply put: you get to see the results before you even shoot the photo.

It’s smaller than the whole prism system that is being used in the SLRs.

There is a low light boost where the sensors on modern cameras are so good, they actually see better than your own eyes in certain lighting conditions.

They’re going to have 100% coverage in most (all) cases, whereas SLRs are sometimes at 95%.

As I said for LCD, it is hard to check your picture under bright light, but with the electronic viewfinder, you can easily review your pictures in the camera.

Video recording. We’re not going to talk about shooting movies here, but with an SLR you have to hold the camera out away from you so that you can see the back screen of the camera. In this case, you can hold the camera up to your eye like a standard video camera, which is a steadier position for holding the camera. You’re going to have better shots because the camera’s not moving around as much.

The information overlay, with an Electronic View Finder, you can display any data you want like exposure data or histograms. You also can add alerts such as one to avoid a blurry shot.

There are so many more things that we can do on camera. It’s just really neat. There’s a long list of advantages to the EVF, and they are improving all the time.


  • What you see is what you get (exposure, depth of field, white balance…)
  • Smaller than SLRs
  • Low light boost
  • Power consumption
  • 100% coverage (vs 95/98 or 100 for SLRs)
  • Image review even in a bright environment through the viewfinder
  • Video recording
  • Information overlay


  • Refresh lag
  • Low dynamic range
  • Power consumption

RANGE FINDER viewing system

This one is not really popular and goes back close to 100 years now. The “rangefinder camera” can be found most notably in the Leicas, and some other brands. Light goes through the lens, to the image sensor, but for viewing purposes, you use a completely separate window. These cameras were very popular back in the ’40s and the ’50s. They are quite small because the light goes from the lens directly to the sensor, and you’re viewing through a separate viewing system.

Range Finder Camera viewing system

On these cameras, the entire area you see is a little bit greater than the actual area that you’re going to be shooting photos of. Street photographers love this because they get to see if somebody is crossing into the frame at a particular time. Another advantage for street photography is that there is no “blackout” unlike with DSLRs when the mirror gets up. Street photographers love this because they get to see that exact moment they want to capture.

Now to focus, there is a separate rangefinder window that has a mirror, bounces light over to the main viewing window, and gives you a slight double image of what you’re focusing at. You may ask why would I want to see a double image? Well, that is for focusing purpose! This system was the most accurate way of manual focusing before the age of digital. Because you get two images, you can overlay one image on top of the other by simply turning the lens until the two images are overlapping. It is effortless, and you have perfect focus. It is an excellent manual focusing system.

Now, these rangefinders do have some notable disadvantages. First one is that you are not looking through the lens, which makes macro lenses and telephoto lenses very challenging to work with. It typically works best with normal to wide lenses. Because of that you also can forget that you have the lens cap on and won’t notice it. That’s something that has happened to everyone who’s owned these types of cameras.

In addition, these systems generally are a bit limited in the variety of lenses and accessories that you can get. Indeed, if you want to do a wide variety of photography, this isn’t probably the right system. This is a little bit more of a customized system for particular types of shooting like street photography.

However, they’re interesting to know about because they have had a significant role in the history of photography.


  • Very accurate manual focus
  • Constant viewing
  • A view outside the image area


  • Not seeing through the lens
  • Parallax effect with macro and telephoto lenses
  • Limited to some type of photography

SLT viewing system

This one is more like a footnote in the history of photography. This is something that Sony is doing exclusively with a few of their SLR-styled cameras. They call it an SLT.

In these cameras, the mirror looks like in a DSLR but does not move up and down. It is a translucent mirror which bounces 1/3 of the light upward to a focusing system and sends two-thirds of the light straight through to the sensor.

SLT Camera viewing system

So obviously, only two-thirds of the light going back to the image sensor is going to be the first disadvantage to this camera as you’re not getting all the light into that image area.

The advantage is that they have a focusing system that is looking at your subject 100% of the time. So, in theory, these make very, very good autofocusing cameras. In practice too! However, they’re not that much better than your standard SLR, so there’s not a massive benefit over SLRs for focusing.

You also do have a continuous viewing system because the light is always going up to that electronic viewfinder which is nice. We do have the advantage of having an electronic viewfinder with all those extra accessories and digital focusing aids. Once again, the image that you see on screen is very much the final image you’re going to get with the exposure and white balance and so forth. However, the downside is we are losing a third of our light, which we never like to do in photography.


  • Continuous focus system
  • Electronic Viewfinder with extra digital focusing aids & info
  • Final image preview (exposure, WB,…)


  • Mirror “steal” 1/3 of the light
  • Focus not significantly faster than classic SLRs
  • Lower quality viewing


It is a little bit of the combination of the rangefinder camera and the electronic viewfinder camera. That system is only used on a couple of cameras (like the Fuji X-Pro2).

Hybrid Camera Viewing System

You do have a viewfinder that you can look through 100% of the time to see what’s going on. However, they have put a little LCD off to the side so that you can choose to see an optical view, or an electronic view, or kind of a combination of the two. It gets the digital overlays which can be nice, and there’s just lots of viewing options, which are very handy. However, there is limited compatibility. Once again, it doesn’t work well with macro lenses, doesn’t work well with telephoto lenses as well. The manual focusing is not quite as nice of an experience as the rangefinder, and it’s got the same limitations as the EVF.


  • Best of both world
  • Digital overlay of the actual image
  • A lot of viewing options


  • Limited compatibility with optics
  • Manual focus not as good as rangefinder
  • Same limitation as EVFs

Other viewing Systems

The optical viewfinder. This can be found on certain point-and-shoots, and this is just what they often call a tunnel window. It’s just a window that you look through to frame up your subject. It doesn’t show focusing; it doesn’t show exposure. It’s just making sure you got the camera pointed in the right direction. Moreover, we see fewer and fewer of those.

The old view cameras, like Ansel Adams, used for instance. You put a big black cloth over the back of it so that you can get the back screen dark enough to look at it because it’s a relatively dim image. Moreover, it was upside down and reversed, and photographers were composing upside down and backward.

Twin lens reflex camera has the light coming in through an upper lens, bouncing off a mirror, and that’s what you’re looking at. In this case, you’re not looking at the actual lens, but at a lens, that’s a very close approximation.

Other viewing Systems