Image artifacts in early TV

[Rinehart]

I found these photos on Steve Restelli's web site historytv.net. They are from Vladimir Zworykin's personal collection of pictures taken of early television broadcasts. There are about sixteen or so in total, most of them show the characteristic faults of iconoscope cameras: edge flaring, shading problems, etc. But these also show curved lines radiating from the edge to the centre. Mr. Restelli tells me that they are on the original photographs, although scanning has accentuated them. He doesn't know what caused them. I've looked through the section on image defects in Fink, but they don't look like any of the examples there. Can anyone hazard a guess at what they might be?

[compu_85]

I would venture those are not visible when viewing the set directly. Cameras never seem to be as good as the eye in this regard.


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[Eric H]

I can see that effect happening with a digital camera because they use Pixels all lined up in rows, but a Film Camera shouldn't do this I don't think.
It might show the blanking interval but the Moire pattern is odd.

Maybe they used some type of polarized Filter on the camera.

[Rinehart]

Would the exposure time have anything to do with it?

[Einar72]

I wonder if this is deterioration of the negatives...

[old_tv_nut]

Please post links to these particular images so we can download them directly instead of the small ones you have posted. There are so many listed at that site that it's hard to find these in particular.

[old_tv_nut]

Well, I found some of them (item #5).

1) the pictures on that site are tiny
2) it looks like they were scanned with totally inadequate resolution
3) this would explain the color moire between the scanner pixels and the scan lines that would be visible in the original pictures. In fact, the way they are two screen images one above the other, I wonder if they were negatives scanned at only a couple of hundred dpi (should be more like 2400 dpi for negatives or similar size positives)

Any way, this effect is NOT in the originals, but in the SCAN of the originals. The fact that the moire is in colors reinforces this conclusion.

[Edit] I wonder if Steve Ristelli would be open to having someone with a decent scanner rescan these? If the problem is not being able to post large images, someone (me for instance) might be willing to post full-resolution scans to Flickr or some other site that can carry them. If you are in contact with him, why don't you ask if he is willing to accept some help improving the posted images.

[Rinehart]

I got a note from Steve Restelli last night, and he has informed me that he no longer has the photographs. As I understand it he sold them, and other things in his collection, because he plans to retire in the near future. He did, however, reiterate that the ripple distortions were present in the original photographs, although they were more pronounced in the scanned images.