AG glass, a kind of fantastic focusing screen

MsLing

Member
Joined
Sep 29, 2023
Messages
139
Location
Guangzhou China
Format
Multi Format
I costumed a piece of AG glass for my Sinar to replace its scarred original screen and inaccurate Fresnel screen, due to its 0.2-0.3 μm grain size. Basically, even focusing through a 20x lupe, grains are invisible while use f/22 or smaller aperture. And image luminance is also as well as Fresnel screen. However, because of its grain size, the haze is lower than normal ground glass, and scattering is way more less, which cause a round image area in view. So user should carry another Fresnel screen or ground glass screen as a viewfinder. Also due to the lower haze, user can only use an apochromatic or achromatic, low distortion and high-eyepoint magnifier, or spherical aberration, coma and chromatic aberration can prevent user form precise result.

As for price, I pay¥100(<$15) for a 100.5*126.5*2mm glass. I recommend that choose a AR coated AG glass, ultra clear glass still leads to strong reflection and flares without dark cloth
 
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