View Full Version : Fresnel glass?
stradibarrius
2-Dec-2011, 15:28
Both my 4x5's have clear glass and Fresnel glass. What does the Fresnel glass do? I read somewhere that the Fresnel could be removed. Why would you remove the Fresnel glass?
The Fresnel 'lens' helps to distribute the light hitting the groundglass so that illumination of the ground glass is reasonable even. The Fresnel is a piece of glass, or plastic, engraved (right word?) with carefully spaced concentric rings. These rings act like a lens to bend the incoming light so that the rays are perpindular to the ground glass.
You can see the effect easily. Look at a brightly lit scene with the Fresnel in place, remove it and then look at the GG again, the difference should be readily apparent. Note: If you decide to remove the Fresnel, be sure to reinstall it in it's original position.
--P
Stradibarrius,
Perhaps you missed it, but this was the subject of a very informative thread just a few days ago: http://www.largeformatphotography.info/forum/showthread.php?t=83616&highlight=fresnel
stradibarrius
3-Dec-2011, 07:28
Thanks that clears it up for me.
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