An Optical Viewfinder
for a DSLR Camera

Original page created on 18/09/2019; updated on 11/12/2019.

Anyone who tried to take a film with a digital camera by framing with the back screen, in full sunlight, will have noticed: it’s just impossible! We can of course act like cellphone owners: framing at a guess… But I don’t like this.

I thought I would find a viewfinder that attaches to the hot shoe, as there are some high-end compact cameras that don’t have a built-in optical viewfinder. But I came across something else, which I didn’t know: a viewfinder that fits to the back screen of the camera.

There are several models, some of which stick directly on the screen, which doesn’t seem very safe. Others are fixed under the camera, by the tripod socket. This is the case of the Tarion TR-V2.

The Tarion TR-V2 optical viewfinder

I received this device less than 24 hours after ordering!

Box contents

When unpacking, we find:

• the viewfinder itself, in plastic material, in two articulated parts, the front portion slides in the attachment part below. Both parts are held together by a magnet. They can be opened to directly observe the screen of the camera;
• the fixing part, in aluminium, also in two parts: the sole which is fixed under the camera, and the U-shaped frame, equipped with knurled screws to adjust the position of the viewfinder and flatten it on the screen of the camera. These two parts are held together by a magnet. We can therefore remove the viewfinder leaving the base screwed under the camera;
• a carrying belt;
• an optical cleaning wipe;
• a 3 mm hex key, of dubious utility, because I didn’t find any screw with hex socket head.

There are no instructions for use, other than the three photos on the box. Despite this, the implementation is simple, and we get this.

Here we see the main purpose of this viewfinder: make the screen visible and usable in direct sunlight. A secondary interest is to help stabilize the camera through an additional support point of the eyepiece on the user’s orbit.

Implementation

First, and most importantly, this viewfinder covers my camera’s entire 3.2 inch screen. All the information is visible, including the “vu meters” for the sound that are at the very edge of the screen, as well as the level scales, the battery charge signal, and so on.

In this photo, where the actual viewfinder is open to allow direct viewing of the screen, a small part of it is hidden to the right. This is because the viewfinder has slid a little to the left, because of the horizontal locking screw that does not block well. I’ll come back to it.

The view is very clear. There is a pincushion distortion, which is not really a problem for use. There is a dioptric adjustment, which is simply to move the internal magnifying lens. I didn’t need to use it to see clearly all the indications of the screen.

The actual viewfinder part easily separates from the fixing part thanks to a mortise and tenon joint held by a strong enough magnet.

Disadvantages

The fixing screw under the camera is not convenient at all: very flat, not knurled, so not manoeuvrable by hand. It lacks wings as on the thumbscrew of my quick-release plate that can be seen below. So, it’s not possible to quickly disassemble the device.

The base is supposed compatible Manfrotto, but I can’t verify, because my tripod is equipped with a Benro quick-release. However, I am able to mount the plate below (there are two standard threads, 1/4” and 3/8”), provided I first remove the viewfinder: the horizontal locking knurled screw prevents mounting or removing the camera as the plate release lever abuts.

Almost all the camera controls remain accessible, except, and this is very awkward, two navigation keys (left and down)…

… and, above all, the photo-video selector.

This defect could have been avoided seemingly easily by spreading the U-shaped bracket from the camera, as on this competitor of £32 (only!)

Solutions

To make the photo-video switch accessible, I had to saw the angle at the top of the U-shaped part, carefully to avoid damaging the viewfinder body (which I was unable to separate from the base), and to prevent aluminium particles from getting into the viewfinder.

I found in use that the horizontal locking screw loosened easily, and, to a lesser degree, those of the sides (vertical lock). Cause: tightening metal on metal, aluminium on aluminium moreover, making fear to tighten too hard, and without washer to distribute the pressure. So I’ve temporarily prepared polystyrene washers ⌀ 4 × 10. Failing that, you can use steel washers, but it’s best to get nylon washers.

In fact, what’s the use of these knurled knobs? They certainly facilitate the setting, but once it’s done, they are no longer useful unless you want to use the viewfinder on several different cameras. So, I replace them with M4 pan head screws, the least bulky. This type of screw is found in Ikea furniture assemblies. Simply shorten them to about 6 mm, either with special pliers or hacksaw, taking care in this case to place a nut that will reform the thread after cutting.

The use of such screws completely clears the navigation keys…

…and allows the camera to be mounted on the quick-release plate without removing the viewfinder.

This time, the screw no longer blocks the release lever on my quick-release receiver.

To be complete, I also replaced the left screw, which was not really necessary.

The only remaining problem is the not yet perfect access to the video selector. The aluminium U-shaped part should be cut further.

After these small works, this viewfinder gives me complete satisfaction.