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Hello Again
Hope it's not to late to resurrect this thread. been doing too much reading and not enough replying, thanks for the link to Rohrs' site Bojan, I'd not thought that he would have tested one of these Diy 131mm x 1000mm lens but it seems that he has and the results are not as good as I wanted them to be but acceptable for the money.
The Strehl figure is the weak link because of astigmatism which may be caused by some misalighnment of the crown & flint or the objective being pinched by an overtight retaining ring,so a bit of tinkering may alleviate some of the "problems". At any rate the lens should work at low to medium powers.
This will be my 6th or 7th home made refractor using new or second hand optics and mostly aluminium tube though 2 have used poly tube and they have worked fine, this one, the 5" f8 will be poly as well.
Also thanks Adam, for the link to the Yahoo Refractor Group, should be lots of info on there to digest.
Kind Regards
Jeff
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