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Message: <blockquote data-quote="typo" data-source="post: 3439599" data-attributes="member: 83808">Jan,Collimation just makes sure the tubes are fairly close to parallel. Confusingly that would also be measured as an angle. Resolution would be done on quite a different instrument though is superficially might look similar. It is essentially a camera with a high quality long lens which is used to determine the limit of detail a binocular is capable of showing. The computerised method used in a commercial lab actually measures something called the modulation transfer function. This a page for a popular analytical package and the MTF plot is at the bottom.<a href="http://www.imatest.com/docs/sharpness/" target="_blank">http://www.imatest.com/docs/sharpness/</a>All you really need to understand is it produces pretty much the same answers as a line chart. The diffraction limit for a 42mm objective is about 2.8 arcseconds. The old ISO requirement for high quality binoculars was they should be better than 5.8 arcseconds and the design standard for something like a HT or SF would be 4.5 arcseconds, but they would specify each sample should be better than 5.2 arcseconds. Chinese OEMs obviously use the same kind of standard. The optical designer is able specify the optical accuracy and aberration distribution of every lens in the light path to achieve that standard. The consequence is the potential to produce a broad range of effective resolution and contrast performance which can be used as a quality differentiator. The ELSV 8x32 and the CL 8x30 would be a reasonable illustration.The Opticron Aurora was specified to be less than 4 arcseconds and the Kite Bonelli seems better still.David</blockquote>

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