After the test cards, what?

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Postby M3DVQ » Tue Apr 17, 2007 3:00 am

I haven't yet completed a real telivisor, but I've done a lot a playing around with the software others have mentioned. as pointed out the problem faces is that the club standard is portrait, favouring headshots, rather than the usual landscape format we are used too.
however, by allowing the led/diffuser/lens assembly to be rotated through 90 degrees around the disc to the top (like in IIRC the german mechanical system) 32 line standard landscape pictures can be obtained. This obviously adds to the mechanical complexity of the viewer, but I'm sure makes it much more useful for actually looking at pictures :-)

I seem to remember a televisor shown at the NBTVA convention last year that was capable of viewing portrait baird signals, and landscape german signals by the rotated light source and mask design.

I have encoded an old bugs bunny film with the avi2wav program in a landscape aspect, here's a very short snippet of the resulting wav file.

I don't know how good it looks on a real machine, but on the software viewer it is very watchable.
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bugs bunny
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Postby gary » Wed Apr 18, 2007 10:50 am

M3DVQ wrote:I haven't yet completed a real telivisor, but I've done a lot a playing around with the software others have mentioned. as pointed out the problem faces is that the club standard is portrait, favouring headshots, rather than the usual landscape format we are used too.
however, by allowing the led/diffuser/lens assembly to be rotated through 90 degrees around the disc to the top (like in IIRC the german mechanical system) 32 line standard landscape pictures can be obtained. This obviously adds to the mechanical complexity of the viewer, but I'm sure makes it much more useful for actually looking at pictures :-)

I seem to remember a televisor shown at the NBTVA convention last year that was capable of viewing portrait baird signals, and landscape german signals by the rotated light source and mask design.

I have encoded an old bugs bunny film with the avi2wav program in a landscape aspect, here's a very short snippet of the resulting wav file.

I don't know how good it looks on a real machine, but on the software viewer it is very watchable.


I wanted to see this video the 'right' way up so I have added a 'widescreen' function to NBTV - The Big Picture!. This function rotates the image 90 degrees and changes the aspect ratio from 3:2 to 2:3.

If anyone is interested in trying this out it is available now from here:

http://users.tpg.com.au/users/gmillard/nbtv%20setup.exe

To use the new function simply select the 'Widescreen' item on the 'view' menu or press Ctrl+W.

Cheers.
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Postby DrZarkov » Wed Apr 18, 2007 4:47 pm

Great! I will try it when I'm back home this evening!

@M3DVQ: Which software you used to create the horizontal NBTV film? I would like to create some films in that "pseudo-german" standard with 32 lines horizontal instead 30 lines simply by turning my club standard disc clockwise and moving the LEDs 90 degrees.
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Postby M3DVQ » Wed Apr 18, 2007 9:26 pm

I simply used the avi2wav program from here http://users.tpg.com.au/users/gmillard/nbtv.htm

first I rotated the video file through 90 degrees clockwise with virtualdub http://www.virtualdub.org/ (but any software to rotate the video should work, virtualdub is just my preferred editor) then fed it through avi2wav. the resulting video is rotated anticlockwise by top viewing the monitor, or by the widescreen option on the viewer software returning it to the correct orientation.
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Postby DrZarkov » Thu Apr 19, 2007 6:39 am

@Gary: I have no luck with the download. Is the link correct?

Edit: I've downloaded the latest version from your homepage, it's working fine! :)
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Re The Big Picture - Widescreen

Postby Phil Hunter » Sat Apr 21, 2007 6:47 am

Gary

Thank You for the alteration to the Big Picture - Any chance of the same widescreen option being added to Video2NBTV ?
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Postby M3DVQ » Sat Apr 21, 2007 7:03 am

I'm planning to come to the convention tomorrow, I'll stick the 5 films I've made onto a CD and bring along if anyone wants to have a go at watching some full cartoons :)
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Re: Re The Big Picture - Widescreen

Postby gary » Sat Apr 21, 2007 3:46 pm

Phil Hunter wrote:Gary

Thank You for the alteration to the Big Picture - Any chance of the same widescreen option being added to Video2NBTV ?


YWIMC: http://users.tpg.com.au/users/gmillard/ ... nstall.exe
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Postby M3DVQ » Sun Apr 22, 2007 7:51 am

M3DVQ wrote:I'm planning to come to the convention tomorrow, I'll stick the 5 films I've made onto a CD and bring along if anyone wants to have a go at watching some full cartoons :)


Well I burnt a CD, brought it to the convention, and then completely forgot about it :oops:
The files are a bit big for uploading here, but if anyone is interested I'm planning on putting an NBTV section on my site, and I'll put the zipped up .wav files on there. It's a home server though, so don't expect lightning fast downloads :-)

[edit]
I've added the NBTV section, it's a bit sparse at the moment, like the rest of my site :P but it can be accessed by clicking on the 'Link to pages on my home server' here; http://myweb.tiscali.co.uk/alistairsportal/
[/edit]
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Re: Re The Big Picture - Widescreen

Postby Phil Hunter » Mon Apr 23, 2007 3:01 am

gary wrote:
Phil Hunter wrote:Gary

Thank You for the alteration to the Big Picture - Any chance of the same widescreen option being added to Video2NBTV ?


YWIMC: http://users.tpg.com.au/users/gmillard/ ... nstall.exe


Gary thank you for the alteration
Regards
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Postby DrZarkov » Mon Apr 23, 2007 4:25 pm

I have an extra wish: Is it possible to add "german system" with scanning from top left to bottmom right? the original system is of course 30 lines, but 32 lines would be fine, too, because I cvan use the same scanning disc.

I made some experiments this weekend with converting some parts of a "Doctor Who" Episode (in black and white, from 1967) to both, vertical and horizontal scanning. I think the picture is looking better with vertical scanning. The files are a little big (about 6 Mb each), if anybody is interested, I can put them on my homepage.
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Postby Klaas Robers » Mon Apr 23, 2007 11:31 pm

Volker,
it is not by accident that J.L.Baird has choosen for vertical scanning and from right to left. When our eyes scan a pictire we do this in the reading way, from left to right and from top to bottom. This is obvious when some words are readable. Then a scanning against the reading direction gives a higher "refresh-rate" than with the reading direction. This is more the case with slow frame scanning (12½ Hz) than with fast frame scanning (50 Hz). I think JLB has done experiments with it.

However someone gets used to certain scanningdirections. Few years ago I saw an experiment with two TV picture tubes on which the same picture was displayed (some lines of readable text). One tube showed quite some strange flicker, almost everybody experienced that. The strange thing was that this was a TV "up side down" connected to an "up side down" video signal. So it scanned line from right to left and frame from bottom to top, normal 50 Hz. Because we are not used to it everybody saw a flicker that was no more seen on the normal scanning directions.

If you reverse mount (front to back) a club-type of nipkow disc and reverse the rotation direction, you have the german scanning way. Denis has some replicas of Telehor machines.
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Postby DrZarkov » Mon Apr 23, 2007 11:48 pm

Well Denis' replicas inspired my to make my own Telehor, but first I would like to do some tests if the german system is of any use. Not without reason they stopped very early in Germany with that system and increased scanning rate and resolution (the same development happened in other countries with horizontal scanning like in the USA or France) while the Baird system was quite long in use, including the dutch experiments until 1939.
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