"The heavens declare the glory of God; the skies proclaim the work of his hands." Psalms 19:1
"Coffee leads men to trifle away their time, scald their chops, and spend their money, all for a little base, black, thick, nasty, bitter, stinking nauseous puddle water." ~The Women's Petition Against Coffee, 1674If it ain't broke, fix it 'til it is.
18" Obsession, NexStar 11 GPS, Celestron 8SE (OTA), NexStar GT102 (OTA), SV80ED f/7 (OTA), iOptron ZEQ25 mount, Porta II mount, Panasonic GH3 camera, Mallincam Jr. PRO, Lunt LS60THa(PT)/B600, Exploradome.
Many Views Yield Truth
I can't hear well, but I can listen!
Takahashi TOA-150 B
Takahashi EM-400 Temma 2M
Handheld Algiz 7
Kagayaki IV Pro
Kmart 40mm-Thanks Mom|Jason60mm-Thanks Dad|C80SS-Thanks Wife|C90|C102|C6XLT|AP130EDFGT|C-11XLT EQ-2|EQ-3|CG5GT|Mach 1 & Eagle "For once you have tasted flight, you will walk the earth with your eyes turned skywards, for there you have been and there you will long to return".-Leonardo da Vinci "We're all in the gutter, but some of us are looking at the stars."-Oscar Wilde ~RIP Dad, you were my best friend...Godspeed!~
Quote:Maybe off topic, but why are there so little " 45° erecting prisma's" used for astronomy viewing? I believe the view's are not upside down, is this the better way to go, or I am wrong?
Quote:The reason you don't want to use a 45 degree diagonal is because most if not all of them will noticeably degrade the image. For terrestrial use I think you are ok
Quote: The advantages of these system are internal focus, low weight and dedicated erector systems.
Quote:I dislike a correct image diagonal for celestial viewing as per the above mentioned reasons,and could care less which direction a bird is "facing" when I'm viewing it in terrestial observation.
It was a 20x power, 0.3° field of view telescope, sporting a singlet objective stopped down to 15 mm that profoundly changed our perspective on earth's place in the universe.
I mostly enjoy small, fast, and (ultra)portable glass: Bushnell Legend 8x42, Pentax PCF WP II 20x60, MiniBorg 60ED, ST-80, EON-80, ST-120, 6" StarBlast.
Quote:Quote:I dislike a correct image diagonal for celestial viewing as per the above mentioned reasons,and could care less which direction a bird is "facing" when I'm viewing it in terrestial observation. It is a bit counterintuitive though, to have to steer your scope to the left when the bird is flying to the right.
Quote: Quote: The advantages of these system are internal focus, low weight and dedicated erector systems. Do you consider these advantages? They can be for birding, probably not for astro. The biggest disadvantage I see to birding scopes, they are limited to 1.25 inch eyepieces. The thing an 80mm does best is provide widefield views that a larger scope cannot. Jon
.... back yard astronomer ================= Don't forget to look at the moon often. Its a play ground of fun if you throttle up the magnification!
Quote:Why do you consider internal focus an advantage for astro? The ones I have used are slower than a good rack and pinion with a two speed.
Quote:It would have to have very large prisms to avoid vignetting with an eyepiece like the 31 mm Nagler. Balance and mounting are issues too when using those big, well corrected eye pieces.Jon