The Viewfinder

The term “viewfinder” is used generically in this page, as in it, I’ll refer to all methods by which we look to see what the camera is seeing when we take a photograph. The general types are the direct optical viewfinder, the traditional mirrored viewfinder, the electronic viewfinder, and live view. There are others, but for the most part, they’re obsolete, and not of interest, other than historically.

Direct Optical Viewfinder — Basically a window that sits close to the lens and gives you an approximation of what the camera is seeing. It is not an effective tool for serious photographers. It’s on point and shoot cameras. That’s all we’ll say about them.

SLR Mirrored Viewfinder — Viewfinder used on SLR cameras. This viewfinder looks directly through the lens, and bounces off three mirrors to show you exactly what the lens sees.

Electronic Viewfinder — In the same location as the SLR mirrored viewfinder, but is composed of a small video screen, and pulls an image from the electronics of the camera, rather than using mirrors to look through the lens.

Live View — Rather than looking through a viewfinder, live view presents an image large enough to be seen from approximately a foot or two away. Live view is on the back of modern DSLRs and mirrorless cameras, and is the only method of photo composition on smart phones.

Modern upper end cameras use either a combination of the mirrored viewfinder/live view or electronic viewfinder/live view. So, what do we need to know about them?
For non-tripod serious camera work, you need to use a viewfinder, either optical or electronic, rather than live view. This is due to human ergonomics and the way we physically react with the camera. Holding the camera further from your body increases the amount of hand shake, and makes it much harder to track action. While there are some instances where live view is acceptable for still photography work, these tend to be specialized situations, such as when you can’t position the camera to get the shot and have your eye to the viewfinder. I’ve used it on several occasions to get photographs of coaches in huddles. It’s better than shooting blind, but you wouldn’t want to do an entire shoot that way. Live view will get washed out in bright sunlight, making it impossible to see the image. Smart phones are easier to use in live view, because they are light and compact. The heavier the weight of the camera, the harder it is to use live view.
On DSLRs, the mirror locks in the up position, blacking out the viewfinder during live view, so when shooting video on a DSLR, live view is the only option. On some cameras, the back screen is hinged and swings away, allowing you to see the screen from angles other than directly behind the camera. Some of the Canon cameras have a particularly good live view screen, that both pivots and rotates. Video bloggers use this a lot for making blogging entries.
If you go DSLR you get a mirrored viewfinder. If you go mirrorless, you get an electronic viewfinder. It’s one of the choices you make when you decide your path.

Most viewfinders have a diopter next to them. The diopter is an adjustment that will allow someone without perfect vision to adjust the viewfinder to their prescription. It’s most often adjusted with a small wheel next to the viewfinder. To adjust your viewfinder, first, get an object in focus while using your prescription eye ware. Then, take the prescription eye ware off, and turn the dial until the image becomes sharp again. The viewfinder is now adjusted to your prescription. It’s not perfect, but is easier than trying to look through glasses while photographing.

While the location within the viewfinder will vary, almost all of them will have an electronic readout of certain camera settings. These are shutter speed, aperture, and exposure level. Some may have the ISO listed. Some cameras will have a number to the far right at the bottom of the screen. If the camera is set to shooting continuously, it’s an estimate of how many photos it will take before having to slow down to write to the card.

There are questions about the difference, in actual use, between optical(mirrored) and electronic viewfinders.

Advantages of mirrored viewfinders

  1. It’s immediate. There’s no lag time.
  2. It doesn’t use camera power, and you don’t have to wait for it to wake up.
  3. It tells you precisely whether your image is in focus
  4. It has as much detail as your eye can resolve

Disadvantages of mirrored viewfinders

  1. The mirror blacks out the viewfinder when you take a photograph. If you see it through the viewfinder, you didn’t get the shot.
  2. Although it will tell you whether or not the image is in focus, it won’t tell you if the image is over or under exposed without checking the exposure meter.

Advantages of electronic viewfinders

  1. If using an electronic shutter, there’s no blackout when taking photos
  2. The viewfinder will tell you almost exactly how the image will look, including exposure levels
  3. Because it’s already electronic, it doesn’t need electronic overlays to show focus points.

Disadvantages of electronic viewfinders

  1. They use power, shortening battery life
  2. They may have lag time and not have as good a resolution as an optical viewfinder.

As of 2018, at least in the high end cameras, the electronic viewfinder functions as well as an optical viewfinder. Technology has advanced to the point that neither shutter lag or screen resolution is an issue.