moondigger Offline Upload & Sell: Off
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HiltonP wrote:
Positioning relative to the mirror isn't an issue since existing t/c's work fine in this regard.
Existing TCs magnify the image, and are designed to work with lenses that don't have rear elements which recess into the camera body. The proposed "neutral" TC would be a flat piece of glass, with a mount thick enough to accept the lens attaching to it. That mount would move the lens forward like an extension tube, and would result in a loss of infinity focus.
Now consider what to do with lenses that have rear elements that protrude into the camera body? Existing TCs are not compatible with these (typically wide-angle) lenses. So for a "neutral" TC to work with them, it couldn't just be a flat piece of glass. It would have to recess into the camera body in such a way as to accept lenses with protruding rear elements. Either that, or it would have to employ an even thicker mount, to move the lens even further away from the camera body, just to get these lenses to mount. And once you've moved those lenses that far away from the camera body, they may not be able to attain any focus whatsoever, much less infinity focus.
Surely any possible distortion (or degradation) or quality would be minimal with a neutral, flat glass plane. Current degradation from 1.4x and 2x t/c's is largely due to their magnification factor. If these were 1x, or neutral, it would be minimal?
Surely any degradation of image quality would be less due to minor dust accumulation on the sensor than it would be with an additional piece of glass and the loss of infinity focus.
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