Is any tester measuring EVF lag?

Discussion in 'Mirrorless Digital Cameras' started by jochen_schrey, Oct 24, 2015.

  1. I am asking about an organisation / notorious blogger / whatever who use a semi scientific rig to measure EVF lag and flaws to generate figures to compare the various mirrorless cameras.
    Here I have some elderly Fujis and feel as if I am loosing track of my environment / subjects, especially in dim light (indoors with flash). Reading about "EVF improvements" in the X-T1 in some reviews doesn't mean anything to me, as long as I can't quantify them.
    Leica bragging about upt to 60FPS refresh rate means little to me, when the displayed footage happened a considerable amount of time before. Also: how few FPS could it be be down to? - Maybe the more interesting question among pessimists.
    So who is publishing test results about this? - I'd really love to sort what I have or could buy into a big picture to make up my mind if I should for example desire an X-T1 or wait for the X-T2 or even 3 to come out. - Switching MILC systems would also be an option for me, but sitting on the fence doesn't hurt either.
    Thanks in advance.
     
  2. DPReview often includes lag time in their reviews. The A7Rii is cited at 23 msec, for example, in the fully-awake mode. I do not notice any appreciable lag from real time. It is consistent with a 60 fps refresh rate.
    I have a good idea about the lag and update frequency from the subjects I shoot, which include a lot of classical concerts. I know that the tip of a conductor's baton moves about 30 mph from the amount of blur at a given shutter speed. The stroboscopic effect in the EVF is comparable to the blur at 1/60 second. I can also coordinate action in the viewfinder with sound. For a musician, 1/100 sec constitutes a noticeable lag. I do not observe a significant lag between the viewfinder and the action.
    I could probably be more objective with electronic triggering and a stroboscope, but I'm not sure that would tell me anything I don't already know. Ten years ago, the lag of a video camera was on the order of 1/10 second, which was maddening. Now, nada. (With a GoPro camera, the lag is over a second. Different camera, different purpose.)
    Your reaction time is much longer, on the order of 250 msec. To capture the peak of action, you must anticipate the moment, or shoot 10 fps and hope for the best.
     
  3. EVF lag can ruin your day, depending on what you're shooting. Here's a link to an article by Thom Hogan where he was shooting sports with four different cameras, and one of them was a Sony A7r Mark II. You can scroll down and see samples of what EVF lag did to some of Thom's shots. HTH
    <http://www.dslrbodies.com/newsviews/shooting-sports.html>
     
  4. The A7Rii is cited at 23 msec​
    I can't find that reference - but found these: http://www.imaging-resource.com/camera-reviews/sony/a7r/sony-a7rA6.HTM - which are significantly longer.
    In any case, those numbers are not the EVF lag but the shutter lag (with and without AF lag) - the question asked here about the time lag between the real action and what shows up on the EVF.
    Here: http://www.dpreview.com/forums/thread/3862069#forum-post-56010287
    it is reported as:
    The LCD is pretty consistently 0.034s delayed from the real-world.
    The EVF varies between 0.032s and 0.087s delayed.
    Naturally, there is no such lag using an OVF. I need to add that with practice on might be able to adapt to that EVF lag - I have not had enough of practice to say one way or the other.
     
  5. My experience with an EVF does not have to do with shutter lag per se. It has to do with delay in showing an image
    when shooting fast action at 10 FPS like swimming or b-ball. It has to do with initial visual capture of a subject and
    focus prior to pressing the shutter. What you see with an optical finder is what you get. There is no perceived delay
    at the speed of light. I had a NEX 5N with an expensive EVF. I felt I was always an instant behind the curve. For me
    it was disorienting. I tried several times to shoot swimming with that combo. It did not work for me. There are other
    problems in low light and dynamic range as stated from reliable sources. The EVF was highly useful on the 5N when
    not engaged in shooting action. The OVF in my previous 7D and now 7DII is clearly better in the side by side
    comparison I made. Maybe EVFs have gotten better. Maybe I just don't have the skill to use them. I have learned to
    compensate and lead a swimmer going up and down doing butterfly so perfhaps with practice I could learn to use one.
    The 7D2 is the fastest capturing, focusing, and tracking camera I have ever used. That is important to me as it leads
    directly to more keepers.
     
  6. My experience with an EVF does not have to do with shutter lag per se. It has to do with delay in showing an image when shooting fast action at 10 FPS like swimming or b-ball.
    The 7D2 is the fastest capturing, focusing, and tracking camera I have ever used. That is important to me as it leads directly to more keepers.​
    exactly, Dick. this is why mirrorless cameras are still questionable for sports/action. With EVFs, you simply have more technical limitations when shooting at high frame rates in AF-C. For mirrorless cameras to truly equal DSLRs in performance, this issue need to be addressed. Otherwise, what pro sports shooter wants to take the chance on missing a critical shot in a sequence, or being behind the action instead of in front of it? it may be possible to get good results using single-shot AF, but then you are relying on guesswork and applying technique as a workaround for technical limitations, not technique as a complement to technical advantages.
     
  7. I tried a little experiment with my A7Rii in continuous shooting mode while panning. The blackout is almost imperceptible, but you see a series of still shots, like stop motion, as the scene exists just at the moment of exposure. I repeated this experiment using the iPad metronome, described in another post. Specifically, the viewfinder shows the scene just before (msec) it is recorded, not afterward. More important, there is no significant delay for the first frame (< 30 msec). I can't speak for other cameras, but there is no "EVF lag", in single or continuous mode in the Sony, when the mechanical shutter is used in whole or in part. (The shutter lag in silent mode is nearly intolerable at about 250 msec.)
    The same operation with my D3 shows a fairly wild situation where the mirror is moving, punctuated by a brief moment of clarity between frames while the camera recovers for the next frame. However the D3 has a cycle rate nearly twice that of the A7Rii, and 80 MB images fill the Sony buffer in about two seconds (JPEG is a better option).
    The A7Rii will take 12 MB images at up to 120 fps in video mode, for 30 minutes at a stretch, and the EVF shows everything in real time. It's called "4K video."
     
  8. Olympus themselves talk about their OM-D EM1-II:
    "Olympus's press release contains the following statement: "With high-speed operation that includes a maximum frame rate of 120 fps and a minimum six-millisecond display time lag during shooting, users will never lose track of fast-moving subjects."​

    With something moving 90mph, 6 ms equates to being 'behind' the object's actual position by 9.5". While that certainly will not affect most folks, it can be problematic for others in the right set of circumstances. Track a jet travelling a slow (for a jet) 300 mph, and .006 sec. means you are aiming behind the jet's actual position by 32". There are some compensatory features that help in that circumstance (for the Sony A9: continuous shooting so shutter lag not an issue, no viewfinder blackout) but focus speed drops from 20 fps to 10 fps during continuous focus tracking.
     
  9. Fuji says this about the XT-1:

    "The improvements mean the X-T1's EVF has a world's shortest delay of just 0.005 second. "
     

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