« The Canon EF 28mm /2.8 | Main | Myths About Megapixels (...And, Does the D800 Have Too Many?) »

Tuesday, 14 February 2012

Comments

"Kodak’s high quality disc camera lens, used in their earlier disc cameras, consisted of 4 glass elements with a focal length of 12.5mm at f/2.8, offering a 58° angle of view. Unlike conventional lenses the second element was an aspheric lens designed to correct spherical aberrations. An aspheric lens was required for its compact design and fast aperture. Without it, extra lens elements would have been needed, adding to the size."

...from http://disccameras.wordpress.com/ I have no idea at all if this is an authoritative source. There's also http://en.wikipedia.org/wiki/File:KodakDiscAspheric-text.svg which shows the lens arrangement and also claims it is glass.

Leica talk of a hybrid form (see digital p12, col 3, para 2 of the Leica lens catalogue at http://en.leica-camera.com/assets/file/download.php?filename=file_1750.pdf )

My guess is that Leica know what they are talking about.

Try the Rochester Optical Works website, proptics.com, search under 'Precision Glass Molded Aspheres'. That makes it quite clear it was glass not plastic, and they made them so they should know. I would post a link but I'm prehistoric with that sort of thing.
All the best, Mark

Plastic, if I remember correctly.

I remember that the Kodak Disc Cameras and the Olympus XA Cameras were interesting because they both had telephoto wide angle lenses. I suspect that some of the camera phones employ telephoto wide angle lenses but have not read anything about it. I remember trying to explain how a Olympus XA had a 35mm telephoto lens. It was almost as bad as trying to explain how the smallest size drink is a "large"

High quality glass paired with miniscule frame size. I don't remember ever seeing a picture from a disc camera that showed the quality of the lens. It may as well have been cheap plastic.

The people we worked with on the fiber optic project said glass. The ones used in the fiber optic project were quite complicated glass moldings, cylindrical, about 4mm diameter and 10 mm long, with a inset lens on one end and an optical flat on the other end.

I see the answer was already provided, but the datum the question triggered in my brain was this: The single greatest contributor to the successful commercialization of molded aspherical lenses was the optical systems of Compact Disc players, during the 1980s. I doubt the Disc Cameras were even 1% of the unit volume of CD players in that decade (or, well, any decade). But Of course, the Disc format did give us advancements in film formulation (isn't T-Grain a result of that format's development?)

I don't know much about lens design, but I know LOTS of trivia about an astounding number of topics.

Patrick

That's some serious crowdsourcing going on here! Well done everyone!

I remember handling one of those disc cameras when I was a kid and I always was amazed that it actually was a camera -- it looked nothing like anything I had seen before. But perhaps I was its only target audience: someone who cared more about a gimmicky camera than the photos.

Pak

U.S. Patent #4,139,677 seems related to the topic ;-)

Weird cameras, those Kodak disc contraptions. I remember the pictures always looked grainy.

I remember the disc cameras saying they had designed the lenses to focus on the curve the film actually took in the cartridges, rather than on a theoretical flat plain. That seemed very advanced and daring at the time -- and still does, actually. In some sense this feels like an early outlier of the current practice of correcting some lens defects in hardware, rather than trying to build a lens without any defects.

For those interested in how Kodak's original technology has been extended, there's a "behind the scenes" article on Nikon's Japanese web site that discusses the development of the 14-24mm f/2.8 and 24-70mm f/2.8 lenses, both of which use very large diameter, radically aspherical PGM lens elements.

The article has more than its share of the cringe-worthy "with joyful hearts, my colleagues and I strove for the glory of the company" sorts of commentary (forgive them; they know not what they do), but it has some interesting tidbits on the interplay between the design and manufacturing engineers over what could and could not be manufactured.

And it's got some interesting pictures of the elements themselves, which are quite visibly large and weirdly shaped. It's here:

http://imaging.nikon.com/history/scenes/25/index.htm

Note also that the Kodak disc was not the first mass-market camera to use an aspherical element. That was the Polaroid SX-70, so far as I know -- a decade earlier.

The comments to this entry are closed.