Search the web
Sign In
New User? Sign Up
Refractors
? Already a member? Sign in to Yahoo!

Yahoo! Groups Tips

Did you know...
Real people. Real stories. See how Yahoo! Groups impacts members worldwide.

Best of Y! Groups

   Check them out and nominate your group.
Having problems with message search? Fill out this form to ensure your group is one of the first to be migrated to the new message search system.

Messages

  Messages Help
Advanced
Messages 30136 - 30165 of 30165   Oldest  |  < Older  |  Newer >  |  Newest
Messages: Simplify | Expand   (Group by Topic) Author Sort by Date ^
30136
Bud, I'm pleased you understand what I'm banging on about. If you take a look at this website, and read my pdf, you may feel sufficiently inspired to buy a kit...
Chris Lord
cjrlord
Offline Send Email
Oct 26, 2009
5:46 pm
30137
Alan, etc.: I purchased 2 of those Gallileo Scopes as soon as they were offered. When the first one arrived I brought it to a Public Outreach session here on...
George
saarmason
Offline Send Email
Oct 26, 2009
7:58 pm
30138
... Don't confuse Bud for Bud. I do have a example of Prof. Mooers' telescope kit. It doesn't quite meet your requirements of duplicating Galileo's Old...
William Hamblen
wrhamblen
Offline Send Email
Oct 26, 2009
11:12 pm
30139
... Bud, I am pretty sure Chris knew who he was talking too! ... I'm the other Bud, the one who knows it is "have an example" rather than "have a example!" ;^)...
Bud Starison
starbuddy84
Offline Send Email
Oct 27, 2009
2:43 am
30140
You could always stop the OG to 38mm. That's about as close as you're going to get with modern lenses. The lenses are good, but not excellent. You would have...
Chris Lord
cjrlord
Offline Send Email
Oct 27, 2009
7:42 am
30141
... I'm sold. I will try one out. ... Agreed. And thank you for the many other facts and tips. Regards, Bud...
Bud Starison
starbuddy84
Offline Send Email
Oct 27, 2009
2:12 pm
30142
Chris, I guess we disagree about a lot of things here. You wrote IYA2009 was supposed to teach people about Galileo's discoveries, not merely tell people about...
Alan French
alandfrench
Offline Send Email
Oct 27, 2009
3:59 pm
30143
When I was in 6th grade, I experimented with lenses. I was not aware of Galileo's telescope or how it worked or what kind of lenses were required to produce an...
uncarollo2
Offline Send Email
Oct 27, 2009
6:07 pm
30144
... Eye relief. ;-) Clear skies, Alan...
Alan French
alandfrench
Offline Send Email
Oct 27, 2009
6:29 pm
30145
... Maybe: "Now why in the blazes would anyone want to look at the fixed sky with it?"...
Richard F.L.R. Snashall
rflrs2000
Offline Send Email
Oct 27, 2009
6:48 pm
30146
... A positive eyepiece scope has lots of eyerelief, but image is upside down. One using a negative lens (like the Galileo scope) has zero eye relief. Rolando...
uncarollo2
Offline Send Email
Oct 27, 2009
9:03 pm
30147
... Sorry, I don't get it. I must be dense today ;^[ Rolando...
uncarollo2
Offline Send Email
Oct 27, 2009
9:04 pm
30148
... Wouldn't a telescope of that day have been used almost exclusively for terrestrial viewing, and as such have wanted, as you mentioned, only the erect...
Richard F.L.R. Snashall
rflrs2000
Offline Send Email
Oct 27, 2009
9:29 pm
30149
... A telescope of that day? I thought Galileo had the only one in his city/country. And he built it himself, for the purpose of exploring the sky. He didn't...
uncarollo2
Offline Send Email
Oct 27, 2009
9:33 pm
30150
... I know. I was joking. :-) Clear skies, Alan...
Alan French
alandfrench
Offline Send Email
Oct 27, 2009
9:47 pm
30151
... Kepler proposed the astronomical telescope in Dioptrice (1611) and Galileo must have had access to the book. Bud...
William Hamblen
wrhamblen
Offline Send Email
Oct 27, 2009
10:37 pm
30152
The reason Galileo directed his telescopes to the heavens was to obtain observational evidence to support his belief in the Copernican hypothesis, a belief he...
Chris Lord
cjrlord
Offline Send Email
Oct 28, 2009
8:53 am
30153
... Thanks Chris! Definitely a most interesting read. Clear skies, Alan...
Alan French
alandfrench
Offline Send Email
Oct 28, 2009
6:46 pm
30154
... As I understand it, Gallileo built a _lot_ of scopes. He was constantly refining what he made. Most he gave away to patrons (in return for patronage <G>). ...
ancient.sull
Offline Send Email
Nov 2, 2009
11:39 pm
30155
The Venetian senate employed what we would now term "a fixer", Paolo Sarpi, to strike a deal with a merchant who had a Perspicillum for sale. Sarpi (who had...
Chris Lord
cjrlord
Offline Send Email
Nov 3, 2009
8:05 am
30156
I am interested in doing a little more imaging using a longer focal length scope, something around f/9 or f/10. I have been looking around and noticed there...
stardaddyed
Offline Send Email
Nov 3, 2009
3:04 pm
30157
I bet that merchant didn't have a very good Astromart rating....
ancient.sull
Offline Send Email
Nov 3, 2009
3:37 pm
30158
Most refractors in that f/ratio range are achromats. You would pick up CA on your images, but there is at least one program that can remove the purple halo. ...
Doug
truckstopast...
Offline Send Email
Nov 3, 2009
6:08 pm
30159
Antares has a 105mm in f/9.5 and even longer - up to 1500mm focal length. Good reputation. http://www.antaresoptical.com/vixen-spec-ota.htm ...
pacobarrena
Offline Send Email
Nov 4, 2009
11:58 pm
30160
Dear group: I have upgraded the focuser of my TAK. TOA-150 and therefore have put up for sale the light green base plate that screws directly into the 7" white...
Phil Dombrowski
philipdombro...
Offline Send Email
Nov 6, 2009
9:55 pm
30161
Would you be interested in a pristine classic Meade 102ED APO? f/9 920mm, with rings, MRF finder, dual speed William Optics rotatable 2" Crayford focuser...
Warp
warpedcorp
Offline Send Email
Nov 8, 2009
8:22 pm
30162
An f/9 ED would be a grand scope to consider. Doug ... -- Doug Truckstop Astronomer [Non-text portions of this message have been removed]...
Doug
truckstopast...
Offline Send Email
Nov 8, 2009
8:33 pm
30163
I'm looking to buy a new refractor. I am considering the Celestron Omni XLT 120mm. Celestron also offers the XLT 102mm ED but for considerable more money and a...
Dan
danacker34
Offline Send Email
Nov 8, 2009
9:18 pm
30164
Dan; Normally speaking it is the level of color correction in a refractor. An achromat has the lowest level of color correction normally speaking and a well...
Rich
astronut1001
Offline Send Email
Nov 8, 2009
9:43 pm
30165
Also, a true Apo is about more than absolute color correction. It's also designed for no spherical aberration, in fact, no aberrations to speak of. An ED can...
Doug
truckstopast...
Offline Send Email
Nov 8, 2009
9:57 pm
Messages 30136 - 30165 of 30165   Oldest  |  < Older  |  Newer >  |  Newest
Advanced
Add to My Yahoo!      XML What's This?

Copyright © 2009 Yahoo! Inc. All rights reserved.
Privacy Policy - Terms of Service - Guidelines - Help