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A Pro's opinion of EVF vs OVF

Started May 30, 2013 | Discussions thread
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Re: Why the writing's not on the wall (and the new link)
In reply to chlamchowder, Jun 1, 2013

chlamchowder wrote:


After using SLRs for 50 years, currently invested in Nikon DX and waiting for the D400, I bought a Nikon 1 V1.  Using it for the past 5 months has brought me to the same conclusion.

I'm hoping Nikon's next major introduction is a DX competitor to the NEX with improved V1 focusing speed and EVF.  That camera could be a smash hit and a huge game changer, IMHO.

  • Focusing speed is not the only factor in how a camera performs for action. The recovery time from a shot and viewfinder responsiveness, for example, also play a role. Like it or not, having light from the subject travel a few more centimeters is faster than waiting for light to expose the sensor, reading data out from the sensor, de-bayering it, sending it to the EVF, and waiting for the EVF to refresh.

Like it or not, the EVF doesn't have to approach the speed of an OVF. It only has to be fast enough so that its delay is imperceptible, faster than the human eye, brain and their chemical pathways. In a couple of years much faster, less expensive EVFs should be available. One DSLR delay that won't get much shorter after those years is the inter-frame blackout due to the mechanical limitations of the mirror.

  • Most people testing the V1 have been using the 30-110 and 10-100 telephoto lenses. At the long end, both lenses have a maximum aperture of f/5.6. The 2.7x crop factor means that 110mm f/5.6 is almost like 300mm f/16 on a full frame camera (110 * 1.4 * 2, losing 3 stops of aperture). With that kind of DOF, the AF system would have to be complete garbage to miss focus. When they can mount a 110mm f/1.0 on a V1, which would be equivalent to a 300/2.8 on full frame, and prove that it still tracks reliably, then it gets interesting.

Smaller sensor cameras may have a DoF advantage, but it doesn't help or hinder AF accuracy. The PD AF sensors act as mini-rangefinders, and in Nikon's DSLRs they use the f/5.6 part of the lens, so f/2.8 lenses don't necessarily focus any more accurately. They may (or may not) focus more quickly, but that's due to a completely different part of the lens design, including mechanical, electronic and algorithmic differences. The AF accuracy is what it is, evaluated at the subject's distance from the camera, not at any distance between an artificial DoF's near limit and far limit. With your V1 vs FF examples at f/5.6 and f/16, the DoF at 30 ft. is a bit under 3 feet for both cameras. The FF camera will focus just as accurately (ignoring the effects of the lens's aperture based focus shift), whether it's shooting at f/2.8 or f/16.

  • The EVF brings a lot of disadvantages, like poor responsiveness and high power consumption (as mentioned above). 

In summary, no, it's not hanging on to tradition. It's that the traditional DSLR design still does a better job in many respects.

EVFs have some disadvantages but so do OVFs. What we do know is that OVFs have for all practical purposes reached the point that they can't be expected to be significantly improved. EVF will keep on improving and just as digital cameras eventually displaced film cameras, EVFs will eventually replace OVFs in all but the cheapest cameras, and even those will eventually fade away. To think otherwise would be just as mistaken as those that loudly shouted not too long ago that film SLRs would never be supplanted by digital cameras.

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