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Message: <blockquote data-quote="Surveyor" data-source="post: 1289216" data-attributes="member: 50720">“Based on what I can interpret there seems to be some variance between the two barrels but that variance is within normally acceptable specs...if I am reading that correctly. Measured resolution is on the high end but some of the distortional imperfections are substandard compared to the big 3. Is that a fair assessment?”  FrankD, Difference between the two sides is common. The only three specifications that are specified (as far as I am aware) are diopter difference, collimation and power. The resolution difference could be my eye position, difference in lighting between the sides, focus error at 80x or difference in aberrations in the tubes. Hopefully, I have controlled the variables so that the difference is caused by aberrations in the optics. I actually had better results using standard test lighting values of 15 EV at 5500K of 3.02 and 3.39 arc seconds. The 3.2 and 3.5 values were obtained with 11 EV at 2800K, a value that most would use indoors and more conservative, more likely for others to match. These are common values, in my opinion, for Big 3 or most other decent optics and not a practical difference since it is about 3 times better than my visual acuity at 8x. For reference the ISO High Performance rejection limit is 60/power=7.5 arc seconds and most of the time you can expect half that value or better. As far as the star test results, I am not qualified to speak to that in any definitive way. I have done very few tests on alpha bins (or any others) so I do not have a reference frame for what is or is not typical. I hope someone like Henry, who has done far more of these, will give me some feedback on the validity of my test and just how typical he deems it to be. Based on my very limited experience I would not be ready to call this substandard though. I am looking for answers more than making a statement about this test. Best,Ron</blockquote>

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