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My latest televisor on Youtube

PostPosted: Mon Mar 29, 2010 2:01 am
by DrZarkov
I've tried to film the picture of my "Zarkovisor V. 4.0" using a normal digital photo-camera. Well, it has of course the same flicker-problem as all NBTV films on Youtube. You can see it here:

I wonder if the picture would be better using a Super8 oder 16 mm camera to film the picture, the flickering should be less disturbing. I've filmed about 25 years ago my "normal" TV set on Super 8, the picture was surprisingly good, even if I used 18 frames/sec on Super 8. How did they film it when they've remade "The man with a flower in his mouth"?

PostPosted: Mon Mar 29, 2010 8:46 am
by holtzman
I liked the piece of music!
When I tried to film "ordinary" tv with CRT on digital camera, the result was very good. The same camera gave awful results with NBTV.

PostPosted: Fri Dec 30, 2011 5:07 pm
by wClarissa
I also once have tried to do as you have said "ordinary" tv on digital camera with CRT and also I have joined the sound separately, the result was good.

Re: My latest televisor on Youtube

PostPosted: Fri Dec 30, 2011 8:07 pm
by Viewmaster
DrZarkov wrote:I've tried to film the picture of my "Zarkovisor V. 4.0" using a normal digital photo-camera. Well, it has of course the same flicker-problem as all NBTV films on Youtube.

Not all........

This one is interesting too in that it is synced to the camera but with the normal flicker line stationary, or near so. ... re=related

I wonder what camera was used to film these? Both are by the same person. Maybe he reads this and can tell us.

PostPosted: Sat Dec 31, 2011 12:33 am
by M3DVQ
Presumably the software solution would be to record at the highest frame rate you can and use some sort of post processing algorithm that can overlap the video frames from the camera.

In fact a standard motion blur seems a pretty good compromise to me.

The one in the VLC video player more or less emulates the phosphor of a crt. A slider controls the persistence.

PostPosted: Wed Jan 02, 2013 2:14 am
by Phil Hunter
Hi volker

I have just read your post regarding your new Televisor
( I have not been on the Forum for a long time)
I have watched the YouTube video
The results are excellent
There are several articles on film rates for when transferring video to film
The BBC used a system of partial frame capture - at roughly 18 FPS
Jeremy Jago and myself have given the problem some thought - it would be possible to film NBTVA at 12.5 FPS and then reconvert to 25 FPS by double scanning each frame
We have a project in hand at an early stage

I think Gary Millard may have some conversion software somewhere.

TMWTFIHM remake was recorded on reel ro reel magnetic tape on 30 lines
The video footage was filmed with a video camera off a 30 line CRT monitor
Hence the interference patterns on the video

Peter Smith and myself were trying to get hold of the original recording to play through our 30 line disks -I am sure the original could be cleaned up and placed on a cd



PostPosted: Wed Jan 02, 2013 4:55 am
by DrZarkov
Hello Phil, thank you for your response. The trouble with most modern digital cameras is, that there is no way to change the framerate. Maybe with a webcam and a suitable software better results would be possible.

PostPosted: Wed Jan 02, 2013 10:45 am
by Phil Hunter
I agree with you
Some form of software would be Ideal, it would be great to be able to show the 30 or 32 line image without interference bars



PostPosted: Wed Jan 02, 2013 10:50 am
by Phil Hunter
Hi Volker

Sorry I forgot to mention my YouTube channel PJ65H has several videos of my latest NBTVA projects including a flying spot scanner and supermarket sourced led light source



PostPosted: Sun Feb 17, 2013 1:58 am
by Klaas Robers
"oldfashioned" video cameras with pickup tubes of the type of vidicon or plumbicon, had an open shutter, so no shutter at all. They were sensitive to the incoming picture for 100% of the time. If you run a Nipkow disc at 50 Hz and have the picture source synchronous to the 625 line TV picture, you will see no flicker at all. I think that happened in the Songfestival video.

Or you should have a camera that you can force to run at 12.5 frames per second and with a short "dead time" that you can force in the black part of the picture.

But indeed it looks much better than in real life.

PostPosted: Sun Feb 17, 2013 2:32 am
by DrZarkov
Hello Klaas, that gives me indeed a reason, why I should buy an oldfashioned camcorder, I always liked them. :)
Luckily I have a PC with a capture card for analogue video.

The past 10 days I was sick, with a flu and otitis. That gave me time to repair one of my televisors with bad sync (now working fine) an to build a new one into an old case I've made earlier. So there is a lot to film now. :lol:

Re: My latest televisor on Youtube

PostPosted: Sun Sep 21, 2014 4:23 pm
by pvogue

As the liquid crystal display now does not have this problem

Re: My latest televisor on Youtube

PostPosted: Thu Oct 23, 2014 7:39 pm
by Klaas Robers
I remember that in the far past, I adapted an "Arriflex" 16 mm camera to run synchronously to the 625 lines TV-sync. This camera had a silvered 180 degrees shutter, so it was open for almost 50% of the time, in which time the film was exposed. In the other 50% the film was transported to the next frame, while the reflection on the shutter's back side was visible in the optical viewfinder. This is comparable to the well known mirror reflex photo camera, where the viewfinder image is also interrupted when the photo is taken.

The Arriflex had a DC-motor of which the speed could be controlled very easily. We made a kind of PLL with the TV frame sync such that the even frames were exposed on the film and the odd frames were viewfindered. After some experimenting a film could be taken off the sreen of a TV monitor without any visible artifacts, and that was the aim of this action. I think that we filmed experiments of the VLP (Video Long Play) in the research and development phase. May be that these films are still present in the Philips Research archieves. At that time (mid 70's) no other way existed to store these TV pictures in a safe way.

Now with CCD cameras these problems are coming back.

Edit later:
The Arriflex had a flash synchronisation contact. A special stroboscope could be used to illuminate the scene in a stroboscopic way. Thus no movement unsharpness would be seen in the film. We used that contact to measure the phase difference compared to the frame sync of the TV system, and keep that contstant. I remember that a small black bar was visible in the optical view finder. By trial and error we knew where the bar should be positioned to get a well exposed film off the TV screen.