Through the lens metering

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On a whim, I did a little experiment with my FT-1 and an incandescent light in my room: I turned the camera on, focused on the light and "panned around" the light, observing the aperture indicator LED's and the light source moved around in the field of view.

It seems the light sensing is most sensitive (wants to stop-down the apreture the most) when the brightest part of the scene is about 1/3 of the way from the bottom of the frame. The left-to-right sensitivity seems less pronounced; top-to-bottom is definitely below the split-image focus, close to where the micro-diaprism "donut" meets the fine ground glass of the focusing screen.

Anyone else observe this? I don't have access to my TC right now, but I think I would have noticed this, that is, I THINK the sensitivity is pretty much "center weighted", rather than this "bottom-center" weighting.

Anyone have any such observations or comments as to why this seems to be the case?

-- tm

-- Anonymous, April 13, 2001

Answers

FT-1 Metering Pattern

Tom -

If you read Jason Cheng's review of the Konica T4 on this site, he talks about the T4's "Variable Angle Metering Pattern." According to the reviewer, for telephoto and normal lenses, the meter is more sensitive toward the center of the screen near the focus aid. With wide angles, the meter is more sensitive in the lower part of the screen. No other reviwer of any of the other camera bodies mentions this metering pattern but it may have been utilized from the T4 forward through later bodies.

Perhaps others with more experience with the various Konica bodies will know.

-- Anonymous, April 13, 2001


Uh-Oh

Sorry, but the review of the T3 indicates a similiar metering pattern.

-- Anonymous, April 13, 2001

TC/FS-1's meter pattern

Please take a look at the following two image files. (sorry for the poor image quality, I scanned them from photo-copies of magazine pages.

http://img.2888.com/others/fs1meter.jpg

http://img.2888.com/others/tcmeter.jpg

The two reviews are: Konica Autoreflex TC: what's new at a glance, Modern Photography. FS-1, Lab Report, Popular Photography, by Norman Goldberg and Michele A. Flank.

The TC's reviews says this about its meter: "The metering system remains Konica's unique cross-eyed cell, center-weighted system, which, in our analysis, showed a heavier central concentration with wide-angle lenses and slightly less with teles - a very good system for preventing possible erroneous wide-angle lens exposure caused by over-generous sky, sea or sand areas."

The FS-1's review did not say the metering pattern, however, the sub title of the figure says "Center-bottomweighted", so...

and I guess FT-1's metering pattern probably is similar to that of FS-1's?

Hope this helps.

Wenbiao

-- Anonymous, April 13, 2001


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