The viewfinder is what you use to set up your shot, plain and simple. Yet, there are a few things about it that you may not know.
This article will help you understand your camera viewfinder better. We go through everything you need to know, from what is a viewfinder to the differences between an optical and digital viewfinder.
What Is the Viewfinder?
The viewfinder is a simple tool that we often take for granted. Back in the day, photographers had to deal with an array of equally frustrating ideas before accurate camera viewfinders came along.
At some point, images were captured by holding a box towards something and exposing the frame. This was definitely hoping for the best.
Most of the viewfinders before the option we have today are almost barbaric. They were basically a small Galilean telescope, sat in the body of the camera.
It gave you a general idea of the scene you wanted to capture. But it had no connection to the lens. Parallax Error was rampant.
As you are framing with one ‘lens’ and shooting with another, the images were never accurate. The closer the subject, the worse the error.
35mm cameras, or SLRs (single lens reflex), such as the Robot Royal III, and medium format cameras such as the Mamiya C330 encountered this problem.
Sports photographers found that the viewfinder was too small to use in such a hectic shooting environment. The Sports Viewfinder was a quick fix for this purpose.
These viewfinders were basically two rectangles stuck on the camera. One was closer to the eye, and the other towards the lens. Here, the photographer just had to line them up to shoot.
Some viewfinders, especially for some medium format types had a ‘waist-level’ viewfinder. The camera would stay closer to your waist as you peered down to find the frame.
These Twin-Lens Reflex (TLR) cameras housed a a large mirror at 45°. This allowed a projection of an image onto a ground glass screen.
Rangefinders came after to help solve this issue of focusing. A range-finding focusing mechanism allowed the photographer to measure the subject distance.
This in turn allowed the photographer to take photographs that are in sharp focus.
Rangefinders still exist today, and hold somewhat of a charm. I still have my Mamiya C330, which I love. The viewfinder doesn’t make or break the image.
On most Canon and Nikon DSLRs, you’ll find a little wheel next to the viewfinder. This is the Diopter. This lets the user change the focus of the image for the viewfinder.
This is helpful to those who wear glasses and wish to photograph without them. The range of strength for this, like most, is -3 to +1.
What We See
The viewfinder is what we use to frame the image. In today’s day and age, we expect to ‘get what you see’. It is true, for the most part.
We have to deal with the viewfinders’ magnification. This can alter our perception of the image. As we now use modern viewfinders, they show us the scenes through the lens (TTL).
By looking through the lens, you get an accurate image. It might be optical or electronic, but having one is much better than not having one at all.
Let’s look over all the things a viewfinder can help with.
Camera Settings/Exposure Triangle
When you look through the viewfinder (optical) or LCD screen (electronic), you see a bunch of information. Some of this information are your camera settings.
More specifically, you get to see the three main components of the exposure triangle. The ISO, shutter speed and aperture are all shown here.
This is helpful to know what you are shooting without having to keep moving your eye from the eye piece. These settings work really well with the Exposure Value (EV) scale.
The EV scale is the bar, usually right in the middle of the bottom section of the viewfinder. It will show a minus scale and a plus scale with ‘0’ in-between.
Used in conjunction with your settings, this helps you get a correct exposure. Your exposure needle should aim to sit around the ‘0’ mark.
Changing your settings will move this scale. If you are in aperture or shutter priority, you can only change this with the Exposure compensation setting.
Focus Points & Metering
We use the viewfinder, not only to frame, but also direct our focus and metering values. A flashing or blinking dot lets us know where the focus lays.
This focus can be automatic, choosing its own points. The user can change the focus zone and mode depending on what they want in focus.
Depending on your metering mode, your viewfinder shows you the scene in which you are metering.
Matrix-Metering (Multi-Zone Metering) mode measures the light intensity in several points in the scene. It then combines the result for a correct exposure.
Center-Weighted Metering looks at the central 60-80% of the scene. This mode is less influenced by the edges.
With Spot Metering, the camera will only measure a very small area of the scene (1-5% of the viewfinder area). This dot is usually the centre, but the user can select a new area.
Handily, you can see your battery level in the viewfinder. You’ll see a battery shape, usually filled with three diagonal blocks.
As your battery loses its full charge, the blocks will disappear one by one. Flashing means you are running on fumes, and can expect to need a new battery very soon.
Having an indicator of how many shots you have remaining is very useful. This lets you know how soon you’ll need to change your memory card.
An optical viewfinder is the little rectangle you use on your camera to frame, focus and meter your shots. It is an optical viewfinder because you use your eye through the glass.
Basically, this optical viewfinder is a reversed telescope, allowing the user to see what the camera sees.
The benefits are basic. Apart from showing you the scene, it give you lots of information about how the camera is working. It doesn’t get burned out from the sun and draws no power from the battery.
It also has a full resolution. This means you see the scene with the same focal length as your lens. The biggest benefit is that it lets you know if your subject is correctly focused.
It’s not uncommon for a modern, digital camera to have two viewfinders. The optical viewfinder and an electronic viewfinder, by using the LCD screen and ‘Live View’.
What Are Pentaprisms & Pentamirrors
A pentaprism, found on high-end, professional DSLRs, uses a prism to redirect light from the lens to the viewfinder. The pentamirror version uses a, ahem, mirror.
These are much brighter and have much higher quality than the pentamirror version. Pentamirrors are usually made from plastic rather than glass.
This reduced quality allows their use in entry-level DSLRs.
A part of the redirected light hits an Auto Focus Sensor, letting you focus an image.
The problem with this system is that the viewfinder becomes blocked when you capture an image. This is not a big deal when you are capturing an image a few thousandths of a second.
But for time-lapses and long exposures, it can be frustrating. As soon as you press the shutter, the mirror flips up to reveal the sensor, blocking out the light.
This is also true of the mirror lock up function, aimed at reducing camera shake when capturing a scene.
The digital viewfinder is usually the LCD screen on the back of a DSLR or mirrorless system. Plain and simple. They use battery power, and can be difficult to see in bright sunny conditions.
The digital viewfinder via way of ‘Live View’ also shows you the exposure of a scene in real time. If you are over-exposing a scene, you will see it immediately.
This is much bigger to use as a way to frame your images. You limit the exposure of the scene based on the brightness of the screen.
My Ricoh GR II only has an electronic viewfinder. This makes the camera smaller too. The LCD screen lets me focus, frame and change or review settings.
It also allows me to capture more candid images, as I’m not holding the camera up to my eye. But, no battery means no view.
Next, check out our great article on using your dominant eye for photography!