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Wrong UK 625 line TV system?

Pre War 240/405, Post War 405 Line, B&W Dual Standard, Colour Dual Standard, B&W S/S 625, Colour S/S 625 line, Hybrids. Standards converters & modulators, video recorders.
 
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Re: Wrong UK 625 line TV system?

Post by Till Eulenspiegel » Mon Aug 08, 2016 5:39 pm

Have you noticed particularly on 405 lines on fast moving images your vision can only see one picture field? You see a 188 line picture.
Effect is worse on large screen sets.

Till Eulenspiegel.

 
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Re: Wrong UK 625 line TV system?

Post by ntscuser » Mon Aug 08, 2016 6:30 pm

Till Eulenspiegel wrote:Have you noticed particularly on 405 lines on fast moving images your vision can only see one picture field? You see a 188 line picture.
Effect is worse on large screen sets.


Likewise, flicker is much more more noticeable because of the interlace. I believe the technical term is "interline twitter".
ttt:

 
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Re: Wrong UK 625 line TV system?

Post by Till Eulenspiegel » Mon Aug 08, 2016 7:39 pm

ntscuser wrote:
Likewise, flicker is much more more noticeable because of the interlace. I believe the technical term is "interline twitter".
ttt:

That's right, interlace twitter = 25Hz?

Till Eulenspiegel.

 
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Re: Wrong UK 625 line TV system?

Post by ntscuser » Wed Aug 17, 2016 1:39 am

And also of course with 1080i you only ever see 540 lines on moving pictures yet people prefer it to flicker-free 720p! :ccf

 
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Re: Wrong UK 625 line TV system?

Post by Michael Watterson » Sun Aug 21, 2016 10:13 pm

There isn't likely to be text/graphic elements less than 4 lines high on HD, hence that issue on 405 / 525 / 635 gone (it wasn't as big an issue on later antialiased caption generators as earlier ones on 625, 525 was worse).
You ARE less able to resolve detail on fast movement, so the the idea of interlace to save 50% bandwidth by reduction of resolution only about 25 Hz was a good compromise.

720p isn't enough resolution for larger screens.
A lot of Cinema content is 24 fps, only recently is 48 fps being used.

It's significant that 480p and 720p are used most for sport in USA and we don't have the equivalent 576p.

It's shame that WS 16:9 was launched before HD and that there MORE HD formats (resolutions & frame rates) than there were Analogue. HD should have been 1152 active lines and 48 fps progressive only. Instead we have five so called HD resolutions up to 1080, progressive / interlaced, 1:1 pixel and anamorphic, Frame rates of: 24p, 25p, 25/50i, 30/60i, 48p, 50p, 60p and interpolated 100p and 120p display, as well as all the PC resolutions and frame rates (43i, 60p, 75p, 5:3, 4:3, 16:10, 16:9, visible lines: 600, 800, 1024, 1200 and higher.) PCs had better than TV HD by 2000, but we have gone backwards on screen resolution on most ordinary PCs/Laptops DOWN to 1080p, which isn't enough for a full page A4 (1200 lines is minimum and we had that in 1990s!). Also 16:9 is a rubbish shape for a laptop screen compared to 4:3.

 
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Re: Wrong UK 625 line TV system?

Post by crackle » Mon Aug 22, 2016 9:15 am

If all you use a computer screen for is for looking at your wide screen holiday snaps then 16:9 ratio is fine. But it is hopeless for actually doing any work on the computer.
The aesthetic properties of the "golden ratio" 1.6:1 have been known for ages, in both mathematics and nature. ( http://io9.gizmodo.com/5985588/15-uncan ... -in-nature ) and the 4:3 ratio is much closer to this than 16:9.
I dont know what others feel about this but 1.6:1 approximates my natural field of view and 16:9 requires one to keep glancing from side to side. (well it does through my glasses)
Ultra wide screen formats like cinamascope and the new apparent new computer monitor standard are just a marketing ploy to say the screen is bigger.
When I was a projectionist in the 70's and 80's the most "normal" ratio was 1.66:1, occasionally 1.33:1 for older films and some films with subtitles.
Mike

 
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Re: Wrong UK 625 line TV system?

Post by Michael Watterson » Mon Aug 22, 2016 9:40 am

Crackle wrote:If all you use a computer screen for is for looking at your wide screen holiday snaps then 16:9 ratio is fine. But it is hopeless for actually doing any work on the computer.


All agreed. Though 16:9 snaps in portrait mode, esp. on a Widescreen are terrible. I just had a show of snaps from someone on my WS TV, and 1/2 looked like shot via Castle slit things for arrows. Ghastly.

I only use my TV for films and browsing snaps. Computer screen only for editing photos.

 
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Re: Wrong UK 625 line TV system?

Post by peter scott » Mon Aug 22, 2016 12:48 pm

I think 4:3 is very much nicer for composition than 16:9.

Peter

 
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Re: Wrong UK 625 line TV system?

Post by Cathovisor » Mon Aug 22, 2016 2:33 pm

Talk shows - especially those made in the format that Wogan did back in the 80s - work best in 4:3 and computer monitors really don't work in 16:9, although I have got used to my laptop being that ratio - I actually found two 4:3 monitors side by side worked better. One colleague actually brought along a 2.35:1 monitor to work which, given the nature of what needed to be on screen, actually worked for him but it's not something you'd use for word processing.

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