Quote:
Originally Posted by mbaddah
I have attached the part I mentioned about gaining 2" of aperature due to it been more reflective. <SNIP>
Have I misunderstood the ad? Cheers all.
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Most scopes have enhanced secondaries these days and for example high end mirror with a correctly applied quartz overcoat ( about 90% reflectance ) gives a total relative aperture drop at 12.5" aperture of 0.37" compared to the Obsession 94% transmission example ( eg 12.12" compared to 11.75" ). No coating coating `gains' aperture. A mirror with an idealised perfect coating can only approach its nominal aperture in transmission not exceed it.
I think the example in the Obsession ads is more comparison with cheap scopes such as the Taiwanese dobs ?