Ever since the Climate Strike march, I’ve been considering the possibility of owning a sports/external finder to help frame fast-changing action quickly.
Unsure of the gadget’s actual worth for my photography, I decided to try one made specifically for my favourite camera, Vitessa A, by its manufacturer — Voigtländer. Though pricey, it was still cheaper than other top-of-the-line finders and featured a unique operational principle.
Voigtländer Kontur takes advantage of stereoscopic vision, our brain’s amazing capacity to combine dual visual input from our eyes into a single image.
You can not see through Kontur — it blocks all the light except the frame lines that “glow” white. With both eyes open, one looking out and the other peering into Kontur, the white lines appear to overlay the visual reality. Because the brain is using unobstructed visual input from the “free” eye, this viewfinder can be used in dim lighting with no issues — as long as you can see anything at all, you’ll be able to use it.
Unlike autostereograms, Kontur does not require any particular effort or technique to work. I found its stereoscopic effect to manifest naturally with and without glasses. However, some reviews suggest that certain vision challenges or disabilities may cause issues using the finder.
Kontur has a huge eyepiece, better than most finders I’ve seen or read about. Still, I found it easier to use with contact lenses than while spectacled.
Build quality-wise, the viewfinder isn’t particularly impressive, nor is it poor. It’s solid, made from very hard plastic, well-machined metal, and proper glass components. It pairs well with Vitessa, a camera for which it’s been advertised as an accessory — though it doesn’t look as exquisite.
Four ways to see the frame lines with Voigtländer Kontur: an experiment.
As I plaid with the finder, I noticed that the outlines it gave over the scene moved slightly as I switched eyes, changed eye dominance, or looked through the camera’s rangefinder window.
☝︎On eye (ocular) dominance: You can observe the effect of eye dominance by extending your hands in front of you and putting them together to make a two-inch circle to peer through — with your thumbs and fingers held together as if you’re wearing mitts: ✋🤚. With both eyes open, focus on an object at a distance that fits inside the circle. Now try closing your eyes one at a time, not moving your hands. The eye that remains open with your object still inside your hand-circle is the dominant one. With a bit of practice, you can train your brain to switch your eye dominance.
Concerned that I may be losing important bits of my scene, I’ve devised a simple experiment with masking tape and a notepad to deduce “the best” way to use my Kontur.
I took four photos, aligning the frame lines from Kontur in various configurations to the masking tape. Then one more using the built-in rangefinder window. All of the test shots were taken one metre away from the window, using Kontur’s dotted line, marked “1m—3ft” with Voigtländer Vitessa A.
I noted the frame number and marked the resulting images: RR) right eye on Kontur with right-eye dominance; RL) right eye on Kontur with left-eye dominance; LR) left eye on Kontur with right-eye dominance; LL) left eye on Kontur with left-eye dominance; and finally RF) right eye looking through Vitessa’s rangefinder window with parallax mask.
✪ Note 1: Eye dominance does not change the frame lines when using Vitessa’s (or any camera’s) built-in finder since all of the information comes from a single source.
Below are the resulting scans, framed with all of the five viewing configurations:
RR) Aligning the scene at 1m with the right eye on Kontur finder and right-eye dominance.
Resting the right eye on Kontur finder with right-eye dominance doesn’t seem to produce very accurate framing. There’s a chunk of the scene cut off on the right, though vertical alignment seems OK.
RL) Aligning the scene at 1m with the right eye on Kontur finder and left-eye dominance.
Resting the right eye on Kontur finder with left-eye dominance looks slightly worse than RR. While the vertical alignment is still good, there’s an extra sliver of the scene on the right that is missing.
LR) Aligning the scene at 1m via the left eye on Kontur finder and right-eye dominance.
A large chunk of the scene to the left is now missing instead of being cut-off on the right. What’s worse, my right eye’s view is obstructed with my right index finger that rests on the camera’s shutter button.
LL) Aligning the scene at 1m via the left eye on Kontur finder and left-eye dominance.
Switching my eye dominance to the left while resting the left eye on Kontur seems to improve the accuracy slightly, bringing it close to the RR. But the shutter finger obstruction is still there.
RF) Aligning the scene at 1m via Vitessa rangefinder window with parallax mask.
Vitessa’s rangefinder window and its parallax mask turned out to be a little less precise than I expected but still significantly better than Kontur. The error is similar to composing with the left eye on the Kontur finder.
Looks like keeping the dominant eye on the finder is the winning combination, with a slightly better experience for those who have their right eye as the dominant one. I will try to keep these findings, i.e. which side is most likely to get cut off, in mind next time I compose the scene with my Vitessa. However, it’s probably easier to make sure that nothing important is within the last 15° on either side of the frame.
These inaccuracies and the lack of DOF preview on rangefinder cameras are perhaps their two biggest disadvantages. Though I still find faster manual focus and quiet leaf shutters worth the trade-off.
✪ Note 2: This experiment is biased by my physiology, which may differ from yours, and by the fact that I’ve tested the accuracy at the distance of one metre only — at infinity, things may be a little different. Also, keep in mind that the camera’s accessory shoe location relative to the lens is likely to alter the results.