MarkLeica 8x20; Nikon Action 7x35; Vixen Apex Pro 8x42; Orion 15x63; Docter Nobilem 15x60WO Megrez II 80 FD / APM 107mm f/6.5 / Mewlon 210 on DM-6 + Berlebach Planet
Quote:what exactly that parameter "optical performance" is? Is it light transmission?
Milton Wilcox R.I.P
Quote:Most often exit pupils of cheap binos look like this one in the attachment. Thus to measure magnification we determinewidest aperture of the pupil. The in-axis vignetting is ratio between the dark area (blocking the light) to the total area of the round pupil.
Quote:Astigmatism is tested by eye. The most important thing is tofocus the binocular as perfect as possible, judge the images of the stars and move focus slightly in and out to check for deformations.
Quote:Since this won't change the relative measurements it seems to me that now I only need to compare the field width of the booster to the field width of the booster+Nikon 8x32 to establish the true magnification of the Nikon and use that as a reference for the others.
Quote:If the binocular is internally stopped down, the exit pupil can remain perfectly round on-axis, and your method will give 0% of vignetting. I am personally surprised by the fact that most of the tested binoculars suffer from very few on-axis vignetting.