10x optical zoom for 4/3 Olympus (28-280)

Started Jun 3, 2003 | Discussions thread
OP brian Senior Member • Posts: 1,211
Some design analysis

There are 17 design examples, and they all seem pretty average in terms of performance. In particular, lateral color is a problem, and there is also heavy wavy-line distortion at the wide end. It may be that Olympus has not published the best mode of the invention (a dangerous practice IMO), or another possibility is that the new 4/3 camera will automatically eliminate lateral color and distortion by in-camera processing using a method similar to this: http://www.caldwellphotographic.com/TutorialsDistortionAndColorFringing.html

The size of the lens seems pretty reasonable: 5" front-vertex-to-image-plane distance at the wide end, and a 60mm diameter front element.

Brian
http://www.caldwellphotographic.com

digital_ray_of_light wrote:
I looked it up on th net, using: http://patft.uspto.gov/

It has a date of Nov 02 - in the text, it goes back to 1999.

I'm not an expert on patents or lens design, so I cannot comment
any further.

Lens experts please jump in!

First sentence from the Abstract:
The invention relates to a compact zoom lens system which can be
applied to a relatively large image pickup device and can maintain
sufficient image-formation capability even at a wide-angle end of
70.degree. or greater and a zoom ratio of about 10 or greater.

brian wrote:

I don't read this group too often, so forgive me if this is common
knowledge. I just discovered a fairly recent Olympus patent the
other day for a 14-140 zoom for the new 4/3 format. Aperture is ~
f/3.5 - f/4.5, 35mm equivalent is approx. 28-280mm, and it appears
to be a legitimate "ED" design with fluor crowns located where they
might actually do some good. The patent number is U.S. 6,483,648.
--
J. Brian Caldwell
http://www.caldwellphotographic.com

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