Steve Backshall - Nature's Microworlds - 2 Serengeti.mp4, b01l4906

Owen Smith owen.smith at cantab.net
Mon Apr 9 13:37:57 PDT 2018


Before you get all fussy about 50i, 50p or 25p you need to look at what your display is doing to that. Most people are viewing on LCDs these days, and these have a "sample and hold" nature of their own and run at a particular frame rate. So you may find everything is being re-sampled to 30p or 60p or who knows what for display on the panel. My point is you likely don't know the LCD frame rate (I don't know any of mine), and it has implications on statements like "50p is better than 25p" which may or may not be true after what the panel does to it. Your preferred frame rate may even be a result of whatever input frame rate is less butchered by your panel on conversion for display.

-- 
Owen Smith <owen.smith at cantab.net>
Cambridge, UK

> On 9 Apr 2018, at 19:22, Tony Quinn <tony at tqvideo.co.uk> wrote:
> 
> 
> 
>> On 09/04/2018 18:34, MacFH - C E Macfarlane wrote:
>> Please see below ...
>> 
>>> On 09/04/2018 16:54, Tony Quinn wrote:
>>> 
>>>> On 09/04/2018 16:23, MacFH - C E Macfarlane wrote:
>>>> 
>>>> Can't see the logic, if there is any?!  Surely, for the same disk space and bandwidth, the customer viewer would get a better download from 1440 25fps rather than 720 50fps?
>>>> 
>>> It doesn't scale quite like that ..... in professional terms, 1080p25 is the same data rate as 720p50
>> 
>> Yes, I can see that that might be so, but I don't think it alters the thrust of my argument, does it?  Wouldn't 1080p25 still be better to watch than 720p50?
>> 
> 
> Not "MIGHT be so" ..... ***IS*** so - having spent 35 years as an engineer in broadcast TV (some of it at the BBC) , I've heard too many bloody amateurs dismiss the physics/maths with phrases like "might be so, but......."
> 
> In my opinion 25p has a nasty "cinematic" feel to it (50i is better) - 50p has smoother movement.
> 
> Added to which just having eyes (which are not stationary) reduces the spatial resolution by the square root of 2 in each direction - increasing temporal resolution is much more effective at convincing the brain that something is "better".
> 
> Read this, and see what I mean https://www.theregister.co.uk/2013/06/25/the_future_of_moving_images_the_eyes_have_it/
> 
> 
> 
> 
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