Shim thickness to replace fresnel

[kw]

Hi Eugene,

Thanks for the clarification! I'll perform the infinity focus on my 90mm with both ground glass and will inform you on the results.

As for focusing on the satinsnow ground glass, its far better than the original Tachihara cover glass and fresnel lens combination. The brightness is about the same, although its just a piece of ground glass, but more important is its ability of achieving a tack sharp image without the fresnel lines! That was my initial discovery with the 210mm lens. I'll update you , once I've tried out on my 90mm.

Besides that, the glass is very well make, even if I compare it with velveteen screen, which I own one. I think Dave at satinsnow has done an excellent job! Just finished my first cup of coffee...

[kw]

I've just finished running the tests with both 90mm and 210mm, focusing at infinity. Interchanging the original Tachihara cover glass/fresnel combination and the satinsnow ground glass in both cases.

The final conclusion, is that the focusing is right on in both cases, therefore no shim is required. For Tachihara users, you may like to check out the satinsnow ground glass, I have no regrets changing to it, for its price and performance.

Thank you for the advices given...