[davidmanze]

Addendum.

It may be that DPR has got the refresh wrong ...... Jarod Polin states 120 HZ !!

[Brightcolours]

Nit just dpr says "60 Hz"... I don't think that a bit higher resolution view finder with a higher refresh rate makes for a better sports camera... Of course, higher than 60 Hz is easier on the eyes. But, with LCDs a lower refresh rate is not that bad as it used to be with CRT screens (yeah i am that old).
But bit more important is the AF, the subject tracking. Which Nikon appears to have nailed with the Z9.

Maybe the Z9 has a 120 Hz refresh rate for its EVF, and a 60hz refresh rate for the live view using the EVF. That means easy on the eyes anyway?

The Canon EVFs have a high res., but don't use it all the time. The Nikon EVF is the brightest, according to Nikon. It probably will be a very nice sports and high res. camera.

[davidmanze]

Nit just dpr says "60 Hz"... I don't think that a bit higher resolution view finder with a higher refresh rate makes for a better sports camera... Of course, higher than 60 Hz is easier on the eyes. But, with LCDs a lower refresh rate is not that bad as it used to be with CRT screens (yeah i am that old).
But bit more important is the AF, the subject tracking. Which Nikon appears to have nailed with the Z9.

Maybe the Z9 has a 120 Hz refresh rate for its EVF, and a 60hz refresh rate for the live view using the EVF. That means easy on the eyes anyway?

The Canon EVFs have a high res., but don't use it all the time. The Nikon EVF is the brightest, according to Nikon. It probably will be a very nice sports and high res. camera.

   Without going down the causes and effects of RR  ....... I would like to know for one which refresh rate it has ? .......... DPR state 60 Hz ....... Jarod Polin says 120 Hz and as he was always critical of the Z6/7 refresh rate, I'm leaning towards 120Hz ........ I must admit it performed like the latter. Matt Granger stated 120 Hz eh!
Btw the R5 performs great with it's 120 Hz RR doing BIF..... I still believe it's because of that ...
 Other than that doubt the Z9 performed well .........

[Brightcolours]

There are two things: the refresh rate of the LCD (like your computer screen, maybe 50 or 60 something else Hz, with LCD screens you don't notice the difference that much. And there is the rate of the video feed, comparable to movie videos (maybe 24 or 25 frames per second, or 30, or 60?).

I am sure the R5 performs exactly the same when you set the view finder to 60 Hz, also with BIF? Just a bit odd that it is not in the Nikon specs.

[davidmanze]

There are two things: the refresh rate of the LCD (like your computer screen, maybe 50 or 60 something else Hz, with LCD screens you don't notice the difference that much. And there is the rate of the video feed, comparable to movie videos (maybe 24 or 25 frames per second, or 30, or 60?).

I am sure the R5 performs exactly the same when you set the view finder to 60 Hz, also with BIF? Just a bit odd that it is not in the Nikon specs.

 Yeah right ....... what's the difference? .. light goes in the lens front and you gaze admiringly into the back top hole ....... and bingo you get pictures ...... I mean  ...... "how sweet is that"?  

 ........ as for refresh rate ...... I don't know about yours, but mine is around two pints an hour ...... not counting the froth ...... but then who's counting ......?   

..... notice how I didn't rise to the bait ? ........

[Brightcolours]

There are two things: the refresh rate of the LCD (like your computer screen, maybe 50 or 60 something else Hz, with LCD screens you don't notice the difference that much. And there is the rate of the video feed, comparable to movie videos (maybe 24 or 25 frames per second, or 30, or 60?).

I am sure the R5 performs exactly the same when you set the view finder to 60 Hz, also with BIF? Just a bit odd that it is not in the Nikon specs.

 Yeah right ....... what's the difference? .. light goes in the lens front and you gaze admiringly into the back top hole ....... and bingo you get pictures ...... I mean  ...... "how sweet is that"?  

 ........ as for refresh rate ...... I don't know about yours, but mine is around two pints an hour ...... not counting the froth ...... but then who's counting ......?   

..... notice how I didn't rise to the bait  ? ........

I don't get your post. Anyway, the difference is, you can watch a 24 frames per second on a 100 Hz refresh rate screen, and have a good time. But a 24 Hz screen would give you a flickering headache.

[davidmanze]

There are two things: the refresh rate of the LCD (like your computer screen, maybe 50 or 60 something else Hz, with LCD screens you don't notice the difference that much. And there is the rate of the video feed, comparable to movie videos (maybe 24 or 25 frames per second, or 30, or 60?).

I am sure the R5 performs exactly the same when you set the view finder to 60 Hz, also with BIF? Just a bit odd that it is not in the Nikon specs.

 Yeah right ....... what's the difference? .. light goes in the lens front and you gaze admiringly into the back top hole ....... and bingo you get pictures ...... I mean  ...... "how sweet is that"?  

 ........ as for refresh rate ...... I don't know about yours, but mine is around two pints an hour ...... not counting the froth ...... but then who's counting ......?   

..... notice how I didn't rise to the bait  ? ........

I don't get your post. Anyway, the difference is, you can watch a 24 frames per second on a 100 Hz refresh rate screen, and have a good time. But a 24 Hz screen would give you a flickering headache.

  My point BC and this applies to stills imaging  ....is ! ....
 ...... Refresh rate has little to do with a smoother flowing visual presentation in an EVF pe se  ....... or for viewing comfort pe se .......... while viewing in the EVF you will be highly unlikely notice the difference between 60 Hz and 120 HZ ........ it is not about that!!

It's primary concern is ........ seeing things as close as possible to real time in the EVF so that the subject appears in the image as close to where it was at the point of exposure when reviewing the image on screen ........ at 60 Hz you have a delay of zero to 1/60 sec ........ which means at certain instances you are behind real time by up to 1/60 ........ at 120 Hz the delay is zero-1/120 sec ....... so closer to real time, thus reducing the issues associated with tracking fast flying birds in terms of subject position in the frame ........ as well as having a lesser accumulation of errors that occurred with early Sonys where the bird got lost in the EVF after a few frames because of the delay ...... (latency)
  Sony wasn't even happy with 120 Hz and went for 240Hz (max) with their A1 ...... at 9.6 million dots ....... at great expense no doubt .......and to great effect .....
   Sport cameras need high read out speeds for reduced rolling shutter and fast refresh rates for remaining as close as possible to real time ...... we are not watching a film here ..... we are just looking at "one single photograph" whether it be on screen or a paper print ....... with the subject appearing as close as possible to where you saw it in the EVF at the point of exposure.
 
  I spent some time trying avoid any ambiguity in this post!

   dave's clichés

[Brightcolours]

You can't see the difference between 60Hz and 120 Hz timing wise.You do not lose any bird with a 60Hz feed, the frequency has nothing to do with your proposed... delay. A strange idea to think that 60Hz somehow makes you lose birds in the frame of the view finder.... The latency you mention had to do with the arrival to the EVF of the whole video stream, not the time between frames.

To illustrate: if you test your reaction time, you can see just how little 1/60th of a second is, let alone half of it (the difference between 1/60th and 1/120th).
I tried this website test once (casually), to see what my score would be. It was around 0.35 seconds. So, about 1/3rd of a second, or 3Hz. 60 / 3 = 20 times longer than what 1/60th of a second actually is, or 40 times bigger than the difference between 60Hz and 120HZ.
http://www.openphotographicsociety.org/shop-and-tools/calculators-and-utilities/time-lapse-calculator/human-reaction-time-test

Why then a higher frame rate? Because, at certain exposure times used by the live view, the feel is more smooth. And, if the live view feed frequency is directly coupled to the read out of the imaging sensor, you get more image/PD data to calculate AF needs.

[davidmanze]

You can't see the difference between 60Hz and 120 Hz timing wise.You do not lose any bird with a 60Hz feed, the frequency has nothing to do with your proposed... delay. A strange idea to think that 60Hz somehow makes you lose birds in the frame of the view finder.... The latency you mention had to do with the arrival to the EVF of the whole video stream, not the time between frames.

To illustrate: if you test your reaction time, you can see just how little 1/60th of a second is, let alone half of it (the difference between 1/60th and 1/120th).
I tried this website test once (casually), to see what my score would be. It was around 0.35 seconds. So, about 1/3rd of a second, or 3Hz. 60 / 3 = 20 times longer than what 1/60th of a second actually is, or 40 times bigger than the difference between 60Hz and 120HZ.
http://www.openphotographicsociety.org/shop-and-tools/calculators-and-utilities/time-lapse-calculator/human-reaction-time-test

Why then a higher frame rate? Because, at certain exposure times used by the live view, the feel is more smooth. And, if the live view feed frequency is directly coupled to the read out of the imaging sensor, you get more image/PD data to calculate AF needs.

    You missed the point again BC muddling the picture with human reaction times  ...... this is sports world @20-30 IPS .....  no single shots here
 ........ the only human reaction time occurs on the initial shutter button press ....... after that the camera rattles 20 IPS while you pan ...... any human reaction times not playing any part at all  .....
 It's clear you only take one shot at a time BC ....... whereas I might shoot 30-40 images with out letting go of the shutter button ...... in fact I rarely shoot one shot at a time ...... only the first one has any human delay ...... surely we are agreed on that ??

  I'll leave you to consider your reply to this part of the discussion ...... because if we are not agreed on that we be will going nowhere !! ........

[Brightcolours]

So now your argument is: You take 20 to 30 shots per second, and the success of all those shots hangs in the balance between 60Hz and 120Hz viewfinders? How does that make sense to you?

The delay of the photographer is something like 1/3rd of a second for the whole sequence you start. And yet 0.016667 of a second influences the bird being framed right? That makes just no sense?