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One of the funniest and most useless threads I have read since the comparing of the EQ6 to the Losmandy Mounts.
Jason, How good is your eyesight, or anyone elses for that matter ?
Unless you want to see your name in print and tell everyone within hearing distance how good your equipment and DSImages are, even if that is so, then any of the Known Manufacturers Optics will be OK. Yes, there is a chance that you could get a lemon but most will exchange or give you are refund.
Mind you, there are also lemons produced by Manufactures who charge ten times of what the everage person spends on his hobby.
More then 90% of the populace wouldn't know the difference between 1 wave optics or 1/50 wave optics. More then 90% of the time you can't even use the full potential of 1/4 wave optics due to atmospheric seeing. Then there are heaps of people who believe anything some people say. Then there are other people who have heaps of money to waste and will tell you the only car to drive is a Rolls.
I don't even know why Mark, who has more experience in mirror making and testing then 99% of the people in this forum, even bothers to get involved in discussions like this. It's a nowin useless exercise. . Unless you have actually tested a mirror yourself, with home made or the most modern equipment, you have no idea what you are talking about. Reading about it makes you an armchair expert, which is worse then a nonsmoker who gave up smoking.
Mirror making was a hobby of mine for near on 30 years, in that time I made somewhere around 250 plus mirrors from 4 1/4" to 16" including 16" RC and SC. I had also the priveledge to meet some of the top mirror makers in that time, and even work with one. All my mirrors were tested in this order, Ronchi, Knife Edge, Null. The only test which gives the same results, temperature controlled, is the Null Test. Any other test is subject to the interpretation of the person and equipment used doing the testing. I have had the priveledge to be present when three highly experienced opticians tested the same mirror with the same equipment in the same locallity and finished up with three different results, mind you, the were still still within % points of each other but still different. The Null Test gave the same result by all three. Strehl is a good rating for a mirror but nowhere near perfect. Mirror with a slight turned edge still had a Strehl of better then .9. It was clearly visible with a Null Test and rejected.
There are that many variables in optical bench testing, setup, quality of equipment, person doing the test, etc. that the only real test is the instrument performance in the field, and that is a Star Test AND How Good Is Your Eyesight.
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