Future upgradeability of new Leica M's EVF

[barjohn]

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You need faster sensor readout than 30fps to be able to drive the EVF faster and have it produce better results. It appears from what I have read from users that have actually tried the one or two cameras that are available in a few limited settings that the EVF is terribbly slow. I doubt if Leica can get a faster readout from the sensor as that is probably fixed by now both from the standpoint of the sensor itself and the processore and code to use the sensor. So...when the new EVF becomes available so will a new camera with a faster readout sensor and a faster processing processor. Those of you that have used any of the APS-C or m43 cameras with a 30fps EVF know that a very slight camera movement results in a perceived large jump in the image after a small delay and on longer lenses it makes focusing hard and framing harder.

[andybarton]

That was not my perception of the EVF at Photokina.

[lct]

30fps is a technical limitation of the M240 and is slow enough to cause motion blur on moving subjects i'm afraid. Fortunately the M240 is basically a rangefinder but those who're after an "R solution" for sports or wildlife photography could well be disappointed by what appears like the main Achilles heel of this otherwise interesting camera so far.

[mjh]

30fps is a technical limitation of the M240 and is slow enough to cause motion blur on moving subjects i'm afraid.

Motion blur depends on the shutter speed, not on the frame rate. A 30 fps frame rate only places a lower bound on the shutter speed which must be 1/30 s or faster.

[lct]

I mean motion blur in the EVF of course.

[mjh]

I mean motion blur in the EVF of course.

So do I.

[darylgo]

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So do I.

 

Michael, could you explain this further, I don't understand the connection between frame rate of an electronic viewfinder and shutter speed, I am under the impression they are independent. Thanks.

[wlaidlaw]

As long as each EVF image is sharp and not motion blurred, you would no more get motion blur than you do with 24 fps cine film. Motion blur as Michael is saying, depends on the length of exposure for each individual frame of the 30/sec refresh rate. Persistence of vision of the human eye means that anything above around 20 frames per second is seen as continuous motion.

 

Wilson

[mjh]

I don't understand the connection between frame rate of an electronic viewfinder and shutter speed, I am under the impression they are independent.

Yes, indeed they are mostly independent, except that the frame rate places a lower bound on shutter speed. That’s the point. When the camera does read-out the sensor 30 times a second, the electronic shutter cannot be slower than 1/30 s – after 1/30 s the next frame is due for read-out, so there’s no time for a longer exposure. But the shutter speed can be (much) faster.

 

For a good live-view image, an EVIL or compact camera needs to control the exposure by modifying aperture, shutter speed, and/or amplification. Now in this case there is no way the M could control the aperture, which leaves shutter speed and amplification. Amplifying the sensor signals can be used to improve a dark image, but if the sensor is overexposed, reducing amplification wouldn’t help. So the biggest burden of exposure control in live-view mode rests on the speed of the electronic shutter. This may vary between 1/30 s and some undocumented fastest shutter speed.

 

So what it boils down to is this: With good lighting the shutter speed will be high and there cannot be discernible motion blur, regardless of the frame rate. In low lighting conditions the camera must lower the shutter speed (increasing motion blur) and/or crank up the amplification (increasing noise). If the frame rate is higher, say 60 or 120 fps, the lower limit on the shutter speed is correspondingly higher (1/60 s or 1/120 s, respectively) so the amplification needs to be higher as well, resulting in more noise. Unless the camera adapts the frame rate to allow for longer exposure times. It’s a trade-off between motion blur and noise.

[AlanG]

In film and video "too short" shutter speeds at 24fps can look choppy when there is motion. A little blur makes things look smoother. I presume it is similar at 30fps.

[pico]

In film and video "too short" shutter speeds at 24fps can look choppy when there is motion. A little blur makes things look smoother. I presume it is similar at 30fps.

 

It depends upon what in the image is being 'tracked' or attended to. A pan tracking a person walking across a room might have the background jittered to a discomforting level, while a stationary camera might create what the eye/brain considers more normal, or more comfortable at the same frame-rate and shutter speed (as you know, they are two different things.)

 

An interesting point: The advent of digital video has begun a change in what we perceive as 'normal' motion pictures, just as digital still cameras have changed what the average person considers normal fidelity (ppi, dynamic range, etc).