Photo Restoration

In terms of cosmological timeframes, 40 plus years isn't too bad.

I imagine the original negatives aboard the spacecraft would have a "better quality" as they are the originals .

Nice one Nick…didn't know about the "flying spot" stuff and other info you mention. I think (as I'm sure – given your knowledge on the subject is much more extensive) that the negative film was a fine-grained low contrast Kodak type, which meant that low graininess at HRes was assured. But I understand that not all went well with the developing stage, as bubbles on the negatives caused splotches/spots…etc., and sometimes the rollers for the film produced darkish bars across them. This, of course, led to parts of image data being lost in the end.

The films onboard the Orbiters were scanned by Cathode Ray Tube (CRT) technology (each scan about 800 pixels), and when the data was received back in the lab (that is, was transmitted through the Deep Space Network to Earth), another CRT transformed the data into an image on 35-mm film. Together, the two CRT effects produced a final image on some with the "venetian blind effect", as it was called (as mentioned above — the image looks like it has a series of lines and variation in brightness across it).

Cheers
John — http://www.moonposter.ie/news.htm

http://www.michaellight.net/fullmoon/

This book (including magnificent panorama fold outs) was a project for the 30th anniversary of the moon landings where Light got hold of the original photos so that they could be restored. (Some were in really bad shape: http://www.michaellight.net/fullmoon/text/digital_procedure.html )

A little reminder of who got there first, perhaps?

The high resolution is available because (summarising the information from John's site) the probe system took 70mm photographs, developed them, then scanned the photographs and streamed the (probably analogue) scanning data straight back to NASA as it came from the instrument – there'd be no way to store the image data on board in electronic form.

So the resolution is limited only by the grain size of the photographic emulsion (pretty small for good-quality 1960s monochrome film), and the resolution of the scanning system. The best image-scanning systems available at the time were 'flying spot' sensors using either an electron beam (as in the TV camera tubes of the period), or a laser, as in the first systems built by astronomers in the 1960s to scan and digitise images on glass plate photographs. The very first imaging CCDs were built in about 1969, and wouldn't become competitive in this sort of application until the 1980s, at the earliest .

The points to remember are that the image being scanned was large and high-resolution compared with the image formed in a TV camera, then or now, and since the image was a still, they could take all the time they wanted, within reason, to scan it at the highest possible resolution.

The engineers who designed the system clearly wanted to capture all the data they possibly could, even though there was no way available (at the time, and within the budget) to reconstruct the images at full resolution.

Hi Rey,

The camera technology back then simply consisted of two cameras onboard each Orbiter — a Medium Res and a High Res camera.

Rather than go on about these, if you like, I have written some brief detail about these at my Moon site (see http://www.moonposter.ie/news.htm)

Cheers