Hello All, Last night we had some great seeing. DSOs with my 200mm, F5 reflector were bright and shiny. Stars resolved well in most of the gobulars I ...
That's the most likely cause. Don't despair, masking off even 1/4 to 1/2 inch might solve the problem. The difference in theoretical resolution between the ...
Getting out my exacto knife right now and making three masks - 7 inch, 7.5 inch and 7.75 inch. Looks like clear skies tonight; I'll let you guys know what I...
I've had good luck just putting the stops on the eyepiece end of the scope. I've also used a mask with an apodizing screen in it to increase planetary ...
Yes, there would be a big difference. Put it at the mirror. -Chris ... From: Tom Nicolaides <tomnicolaides@...> Date: Thursday, February 10, 2005 8:52...
It's a common practice with Newtonians to put an aperature mask on the front of the scope. One of the most common is on large scopes, where a smaller hole, ...
Yes, the tube cover of this Konus has such a hole already in it. It's about 3 inches in diameter. I wish I'd thought to try that last night. But Chris says...
Yep. It is one thing if you are trying to cut incoming light or turn your scope into an unobstructed planetary rig but it is quite another if you are trying to...
Is that because the reflected light from the bad mirror edge (coming from off-axis sources) could be reflected back into the on-axis optical path if it's not...
Some TDE links... "ring of thick matt black-painted card about 5mm above the edge of the mirror" http://www.btinternet.com/~mike.hanlon/mirror_testing.htm ...
If I can find my books, I'll look it up in my Allan J. Thompson and Jean Texereau. I know that a book I had by astro-photographer George T. Keene mentioned ...
It probably depends on if the optical defect in question is throwing errant light back into the optical train or not. i.e. if the suspected TDE turns out to...
Just got back in. I made a 1/4 inch cardboard mask for the outer edge of the primary. Star patterns are now near textbook. Dim objects looked exactly the...
I'm no expert, but I do think Chris's idea below would be best. Just remember when before you take the mirror cell and base off the tube, to mark both so you...
Good show. Don't fret it too much. The theoretical resolution of the new aperature is 188/200 = .94, very little difference. Especially since most of the...
Tom, Since no one else asked this, I will ask. How do you know you had great seeing? Did you try to split some close double stars? When you operate your f5 at...
Randy, This was after several nights of various seeing conditions. What I didn't say was that it wasn't just the view of Jupiter that made me think I had the...
It's a diffraction mask placed around the objective. It is reported to increase contrast for some times of telescopic objects. Here's a couple of good links:...
... You can do a simple ronci test by finding a bright star, removing the eyepiece and placing a ronci rulling on the focuser draw tube. by moving the grating...
This is sort of cool so I thought I would share it: http://www.lzos.ru Check out the factory tour video too. Interesting listening to the British English with...
Hmm.. maybe that wasn't it. Yesterday I put a new focuser on the Konus. The original was peculiar. It was somewhat larger than 2 inch and required an...
Well I will be at NEAF again this year, April 16& 17. http://www.rocklandastronomy.com/neaf.htm It was so much fun last year that I just had to go again! ...
Hello to all! Awhile ago I rec'd an offer to buy a new Orion Sky Pro 8 OTA for under $100. As I own a medium sized SCT and four refractors, two of which are...
Wally, ... You have seen what I have been trying to tell people for years. A Good 8" newtonian will perform very well. As well as if not better than refractors...
... Unfortunately that is simply not true. The 6" APO (since you seem to be talking about APO's and not achro's) no only does not have a central obstruction,...
Randy, Thanks for the responses which I'd like to comment on: I agree..an 8" Newt is an excellent instrument as it has adequate aperture, resolution, and is...
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