You'd be hard pressed to prove any of this to me in the practical use of
my E-M5. I just went back to some shots I took of my 10 year-old
grandson pitching a baseball last summer. Throughout the game I took 26
shots of his pitches. My intention was to capture the ball in the air
shortly after it left his hand. The question is, how difficult is this
to do given the speed of the ball, E-M5 EVF and shutter delay and the
reaction time of a 70 year-old man.
According to some stats I just found online, 10 year-old pitchers throw
the ball at 40-50 mph. I'll assume he can throw at 45 mph or 66
feet/second. For my own reaction time I found a couple of different
studies which indicated that college age males have a "simple reaction
time" (to a visual stimulus) of 190ms. Another study told me that,
after the age of 20, reaction time decreases by 0.5ms/year of age. That
means my own simple reaction time at age 70 is probably about 190+25 =
215ms. Since my E-M5 has shutter shock delay set there is another 125ms
delay beyond my simple reaction time... for a total delay of 340ms
between visual stimulus and shutter firing. Note immediately that my
own reaction time is almost twice as large as the shutter delay.
At 66 feet/second the ball can travel 22.4 feet in 340ms. So, how well
did I do in capturing the ball in the air? These shots were at 150mm
and the distance from his head to the edge of the frame is about 8 feet
(or the distance the ball can travel in roughly 1/3 of the total
reaction/shutter delay time). In 13 of the 26 shots the ball is already
some unknown distance out of the frame. In 5 it's still in his hand at
the very top of the swing. In 8 it's still within the frame somewhere
between his hand and perhaps 6-7 feet away.
Since my own reaction time alone is too long to capture the ball within
the frame, my success rate depends on my ability to predict the right
time to press the shutter. I think I did pretty well. I'm not at all
sure I'd do any better with an OM-1. It's hard for me to believe that
the viewfinder electronics adds anything significant to the 340ms total
already there.
Chuck Norcutt
On 2/15/2014 3:15 AM, Peter Klein wrote:
> A while back we had a discussion of the EVF delay in the OM-D E-M5. I
> found that it lagged significantly behind real life--enough that it was
> very difficult to nab a fleeting "decisive moment." Example: I could
> not catch the instant of ball meeting the raquet in a very gentle family
> game of duffer tennis. I have no trouble doing such things with a Leica
> RF or a DSLR. I also found that if I put an external optical viewfinder
> in the hot shoe, the problem went away, and results were similar to a
> Leica RF. So the problem is not *shutter* lag, but the EVF. I later
> confirmed that the viewfinder had lag by photographing an electronic
> metronome with the sound turned off.
>
> Someone (I believe Moose) suggested that that there was a custom menu
> option to speed up the viewfinder refresh rate. This week I tried using
> this. I do not believe it helped.
>
> The setting is in Custom Menu J (EVF). The item is Frame Rate. "Normal"
> is 120 frames per second, and "High" is 240 frames/sec. The manual says
> that High reduces viewfinder lag. Fooling around with photographing the
> metronome, I got pretty much the same results with High as with Normal.
> Yes, my fallible human reaction time is part of the measurement, but
> things average out to about the same.
>
> My guess is that the "viewfinder" lag they refer to is image tearing in
> video, not the lag behind the action in front of the lens. Also, the
> delay I'm experiencing appears to be something like 1/8 of a second, or
> 125 ms, as seen on my metronome. The difference between 120 and 240
> frames/sec is 8.3 vs. 4.2 milliseconds. Nowhere near enough to account
> for what I'm seeing. So the lag has nothing to do with the refresh
> rate--it's built into the chain between the sensor and the EVF.
>
> So my question now is: Has the E-M1 improved on this significantly?
> This subject is rarefied enough that no reviews I've read address it.
> Steve Huff says that everything about the camera is faster, but I'd like
> to know what and how much. I'd also like to know how much if any the
> shutter shock has been mitigated, because this means I must add yet
> another 1/8 second delay if I want sharp pictures.
>
> Sometimes all this doesn't matter--often actions and expressions "peak
> and hold." But somtimes the E-M5 doesn't cut it for fast "people
> photography." A pity, because it is so very, very good at so much else.
>
> --Peter
>
>
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