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Re: Vignetted optics

Started by dan janosick, 04/06/2007 07:07AM
Posted 04/06/2007 07:07AM Opening Post
Robert,
I tend to agree with you. I had a flt132 from WO and retruned the scope for a refund after some mechanical and optical issues. Your point is interesting since the scope I returned had a turned edge. Maybe the front bafle was not close enough to the lense cell to mask any optical defect?
dan
Posted 04/09/2007 07:58AM #1
I am or at least was a dealer for William Optics, even if I do not sell much of here stuff, due some special reasons, I could not name anybody and I tried not to name anybody.

So , I am very much surprised that Sky and Tel. does indeet mention it a very little bit. Now if S + T would have done a closer look, they would see that all 3 baffles in the M 90 has the same clear aperture and the front does not only vignete 3 mm, it vignetes 3 mm at each side :-(.

In a Refractor baffles shall start wide and get smaller in aperture as closer you go to focuse.

Why in the world William use in the M 90 , 3 same diameter baffles is extremly magic to me.

I reported that issue to William as a fault when I got the first M 90. They told me they will check and if I am right they will correct the problem. Later on I saw another newer M 90 , much later delivered and nothing was corrected.

My one showed with vigneting good optics and colorcorrection, way better then Sky 90, but the baffles are sitting on felt and anybody can simple replace them to correct position, but be carefull, if you correct the problem, your optics show visible more color then Sky 90 and worser spherical correction.

Sames happened to thr M 110F/7 triplet, when I saw and startested first I was surpricest to see a colorcorrection as good as in my russian TMB 115/7 triplet, but when I found here also the vigneting, and corrected it, the colorcorrection dropped below our russian TMB 105 F/6.2

All I found was reported to the manufactor, but nobody took care.

Now have a look in your new Meade 80 mm ED and look what you see from end of the focuser ? A baffle which vignetes the aperture to 60 mm is sitting in the focuser . This was reported to the Meade USA people and Meade Europe and both did not feel it necassary to correct that foolish fault. This year WSP I still saw that bad vigneting baffle.

To me above makes clear , that it is not a lazy assembly mistake, but a clear wanted vigneting.

Here in Germany recently a review in our big magazin was posted by a imager baout diffrent new asian 80 mm Apos. I got the review before printing for read and offer technical corrections . I told them what I know and told to the magazin people if they post this review this written way, then they will support manufactors to foolish customers. The review was printed with no change.
Last week the advertising boss of the magazin called meand asked me how I am doing and i told them i feel extremly dissapointed about the handling of my statement, that nothing was done against this foolish review from the magazin. The Boss told me I am right and he will talk strong words to the responser people and will inform me what he find out. I am waiting !

Now I go away , I do not want to geet the same attacks again as last time.

Reviewing telescopes with sich high pride in a magazin, by knowing such faults is a shame and in my opinion a support of the magazin to the manufactors to foolish the readers, customers.

I am sorry but I cannot understand all that anylonger . But the worsest of the worsest are customers who read all this and still support the manufactors who foolish customers this bad way.

bye byee

Markus

clear skies

Markus Ludes
APM-Telescopes/Germany