Metering component location of D200

Dear All,

 

Where is the metering component of D200? Is it in the prism or behind the

mirror? or anywhere else?

 

If it is in the prism, that is metering will be affected by the focusing

screen, isn't it?

First of all I have no idea, but can guess only, so whatever follows is a guess.

If you think of the matrix, metering, you have intensity of the multiple segments of the scene to judge. To do that you need an image and that forms in the camera only at the focusing screen, so the metering instrument/detector has to be after that. Same is true for the other metering options like spot metering etc. So my guess is the detectors are after the screen, behind the pentaprism.

Now if how much intensity after the screen corresponds to how much there at the LCD is known, what you have mentioned can not be a problem. This ratio is fixed for a design/camera, so no problem.

I will like to look at the experts reply also.

If memory serves me, the D200 uses the principle of a secondary mirror hinged piggy-back on the main mirror, and semi-transparent areas that allow light to arrive on the secondary mirror. The metering (and AF) circuitry is in the lower part of the mirror chamber (seated in a small depression, easily observable if the mirror is raised).

 

Still, even a system like this can be influenced by strong backlighting through the ocular, so it is always prudent to shield the finder with your hand during the exposure, in particular if the camera is on a tripod. Unfortunately, the D200 lacks the built-in ocular shutter that is included with the higher-end Nikons, but most users will have the needed spare hand available :)

It is in the bottom of your camera, you can see it when the mirror is in the cleaning position. Light goes through the middle of the main mirror and is reflected down by a small mirror connected to the main mirror, you can also see that in the cleaning position. Then it is closed and against the mirror, when the mirror goes downs it comes in a 90 degree angle.

I would assume that it is in the prism because websites like Katz Eye say that their brighter focusing screens DO affect metering. I cannot imagine how they could do that otherwise.