Will we see lenses with this technology? Using Aspheres To Increase Optical System Pe

[mtbdudex]

I get NASA tech briefs at work, interesting article in April-2010 edition "Using Aspheres To Increase Optical System Performance" http://www.ptbmagazine.com/features/2010/feat1_0410.html

I can grasp the article, for those in the field, do you think we'll see lens with this technology in near term 2-3 years?

Or is this more 5+ years away due to sunk investment of existing facilities/etc?

Better PQ lens, lighter weight, looks like win-win to me.

 

[anubis]

Consumer lenses have contained aspheric elements for a long time. For example I think all L-series Canon lenses have aspheres; that's part of what makes them more expensive.

This article focuses on a double gauss lens design. Note that most high end lenses (L-series, etc) are much more complicated than a double gauss system and contain significantly more lens elements.

 

[Abraxsis]

^^^^ Ditto

You must remember that NASA does things on a much larger scale than lens makers do. 3-4" in diameter in this forum, 3-4' over in the Astrophotography forum

Aspherical lenses have been used in eye glasses for more than a decade. Combined with higher and higher refractive indices you can get MUCH thinner lenses in much higher powers. A -9.50 diopter lens 15 years ago would be the thickness of a coke bottle (glass) bottom, made of glass and very heavy. Now a -9.50 diopter lens might be a 1/8" thick at the widest point, made of bullet proof polycarbonate plastics, and weighs next to nothing.

Ive found that lens technology is a trickle UP field. Zeiss, Nikon, Canon, etc. make these superb lenses for cameras and glasses, and then the tech filters up to people like NASA who want to use the same tech only on a scale several hundred times larger.

 

[Ruahrc]

Indeed aspherical lens elements have been around for a long time. Ken Rockwell says 1968 was the first Nikon lens with aspherical elements (http://www.kenrockwell.com/nikon/nikortek.htm#aspherical). Recently they have become much more common, to the point where many entry level consumer lenses will feature them as well.

If I understand it right, the concept of aspheric lens elements is not new or novel. The optical phyisics calculations have been known at least a hundred years or more. The main problem in implementation was both solving the equations to get the precise shapes (likely requiring numerical methods on a computer) and manufacturing the complicated aspheric surfaces accurately. The first aspheric lens elements in Nikon lenses were actually hand-ground, leading to fantastically expensive lenses with only one maybe two aspheric elements. A good example is the "legendary" 28mm f1.4, which had a precision ground aspheric element. It can be argued that the aspheric element was what made it cost so much in the first place, leading to its low production/sales, and resulting in its highly inflated value today. Nowadays computer aided manufacturing techniques can produce aspheric elements at a much lower cost, and hence you see them in even common consumer lenses or see 3 or 4 in a complicated lens design.

Here was a good read on how they can be made nowadays:
http://photo.net/nikon-camera-forum/00UtIt

An interesting aside, and to give some perspective, electron microscopes are facing the same problems that early optical systems had. Electron microscopes use "magnetic lenses" to focus the beam of electrons onto the imaging sample. I have heard the analogy that the best magnetic lenses available are like looking through coke bottle bottoms compared to modern optics. In other words, optical technology is highly refined and considering the quality of images you can get with electron microscope "coke bottle" lenses, it is truly astounding what is possible with modern optical elements.

Ruahrc