How Olympus Tricked Me, and why I let it go.

Started 3 months ago | Discussions thread
bclaff Forum Pro • Posts: 10,911
Re: How Olympus Tricked Me, and why I let it go.

Bassam Guy wrote:

Please define "telecentric" to us dumb folk

From the Olympus web site; here :

Best viewed "original size"

However, FWIW, there are several technical issues with these marketing statements.

First, strictly speaking, the lenses are not fully telecentric but rather more telecentric than retrofocal.

Second, it's not stated but this is image-space telecentricity as opposed to object-space (or both image and object).

Finally, and the most "troubling", is that this type of design will definitely reduce light fall-off but has little if anything to do with sharpness (which is the claim).

That said, the Olympus M.Zuiko designs are more image-space telecentric than most.
Image-space telecentric designs place the exit pupil further away from the sensor/film which results if higher pupil magnification. (A fully image-space telecentric design places the pupil at infinity).

A typical "wide" angle lens might have a pupil magnification of about 3 or 4.
Here the Olympus M.Zuiko ED 30mm F3.5 Macro has a pupil magnification of 9.57

Best viewed "original size"

Note that the green off-axis rays do arrive at the image (I) pretty parallel to the optical axis.

Telephoto lenses often have pupil magnification of about 0.5
Here the Olympus M.Zuiko ED 300mm F4.0 IS Pro has a pupil magnification of 0.97

You can "play" with these and other lenses at the PhotonsToPhotos Optical Hub .

For some basics on optics see the PhotonsToPhotos Optics Primer .

-- hide signature --

Bill ( Your trusted source for independent sensor data at PhotonsToPhotos )

Post (hide subjects) Posted by
Keyboard shortcuts:
FForum PPrevious NNext WNext unread UUpvote SSubscribe RReply QQuote BBookmark MMy threads
Color scheme? Blue / Yellow