The Nikon D200, as good as it is, I've always disliked the standard (Canon like) Nikon D200 eye piece, here is what you do to replace the DK-21 with a better one (in my opinion anyway).

The standard is the Nikon DK-21. To replace this with something that actually block your side vision we need a bigger cup.

Here are the parts you need:

• Nikon DK-3 rubber eye cup
• Nikon eyepiece adapter (ring)
• Nikon eyepiece adapter (shoe)

Now you will have an eyepiece that is big enough to press your eye into and effectively block light entering your eye from the side. The nice thing about this is that it's cheap, a mere $26.85.

So, head on over to B&H Photo Video and place your order.

A little warning: As I've used this combination on my D200 for some time now, I have found a weakness with the DK-22 adapter; it can break after I while if you remove/re-attach it to the camera body enough times, so be sure to get more of them so you have replacements when it happens.