Shrouds serve more than just one function: --they keep body heat currents out of the optical path --they keep the mirror safe from children's hands or tools...
My truss Dob coversion of a Hardon 12" Dob has a baffle in front of the primary in the mirror box and after building it I found adding one on each end of the...
"-they help dampen vibration in the truss poles." I can personally vouch for this statement, especially when the scope is pointed 45 Deg or less from the...
"Not everyone agrees with her..." ? Hardly anyone does! ;) Someone has to challenge the old myths. I will agree to disagree you Don on almost every point....
<<I went a month without a shroud while it was being made, and I can speak from personal experience that the presence of a shroud made an appreciable ...
Just to counter point in good humor since I've run my home built 20-inch since 2001 sans shroud, but very good baffles and like Michelle, like to offer...
Bob, where were you when Astronomy decided to feature my scopes in the September issue? I don't know where they got that comment about shrouds... I wish they...
... A baffle like this on the front cage can vignette the light path of off-axis stars. If you use 2" EPs, the front cage ID should be 2" larger than your ...
Hi Michelle, I just noticed your spread in Astronomy. Very nice. Regardless of their comments, it is good to have your scope displayed there. I think their...
You know, I sort of feel singled out in this presentation by Astronomy. I'm not offended by someone's opinion. But when it is stated as fact AND is the only...
... instead (ie. focuser baffle, baffle opposite focuser, around primary - all covered with light-trapping material) ? ... use properly designed baffles...
Don, Just want to zoom in on your comment about the stiffness. ... I understand that the shroud could make a difference for the vibrations of very long truss...
Robert, I wouldn't have used 1" tubes on a scope with a typical UTA on a 25"-- that weight would allow too much sag (as viewed through an autocollimator). If...
Don, ... Now here's a contradiction. I observe quite often in intermittent northern breezes (the famous "mistral" in the south of France). Using a shroud would...
Robert, You're right about wind. The vibration mode I was referrring to is of the type when a breeze blows that is not strong enough to actually move the ...
The following bigdob poll is now closed. Here are the final results: POLL QUESTION: Do we need a new picture for the Home Page? I've been starring at that...
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Enter your vote today! A new poll has been created for the bigdob group: Choose the next photo for the bigdob front page. Candidates are in the photo section...
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Hello, Michelle, Well, this baffling topic is shrouded in mystery. But, since some prospective buyers might want a shroud and some will not, why not offer one...
For anyone sitting on the fence, please do a google on "how does dew form". This is simple physics. Contrary to some popular opinion, dew does not fall from...
Michelle, ... Using a shroud or not is mostly just a matter of personal taste and practical choice. There are as few valid reasons for being "anti-shroud" as...
Off axis light, off axis light, and finally; off axis light. The only light that should be hitting the primary mirror is the light that comes through the top...
... Thanks. The mirror is 1 5/8" thick and weighs 31 pounds, about half the weight of the scope overall. It sits on a 6 point flotation cell, with two edge ...
Kyle, Don't share your off axis light secret with the big observatories... okay? ;) The big dobs are made to be transportable. That's why they are made to ...
Ok Michelle, you've 1/2 convinced me. Since my scope is OVERLY BAFFLED, I'm going to make it a seasonal thing. In the late spring, summer, and early fall,...
... As a long time SCT user, I've become something of an expert on dew over the years. ... Right. The black exterior surface will radiate its heat rapidly,...
That would be true if the primary mirror was flat, like the secondary mirror. But an off axis light ray, hitting a concave primary mirror? Who knows where...
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