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Old 07-07-2018, 12:45 PM
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gregbradley
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Join Date: Feb 2006
Location: Sydney
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Quote:
Originally Posted by LewisM View Post
Plenty of us use FSQ-106ED's for visual - in fact, it's one of the nicer visual scopes I have used, particularly since it is entirely flat in 2" or 1.25" EP's. Plus you can fit the extender to it too, making it f/8 and again lovely for visual AND imaging. Pkus you can also use the reducer with the ED line, making it VERY VERY fast.

Those black bars you saw in the FSQ-106N are NOT vignetting - it is a diffraction spike caused by the spacer foil in the objective (rectified in the FSQ-106ED series with a minor stopping ring). Many Taks have this - it even has it's own nick-name "lighthouse effect".
Thanks Lewis. Yes perhaps I was being quick to write it off visually. I only looked through mine a few times.

The vignetting I got that from Roland Christen who said that's what it was. Perhaps it wasn't right. I have seen that effect rarely on say a camera lens but not so much on a telescope. A weird one. So its those little pieces of aluminium that are separating the lenses and stick out a tad?

Greg
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