neil what's the name of the folder and is it in the files or photos area? tnx jtm ... From: "Neil Carroll" <ncarz@...> To: <bigdob@yahoogroups.com> ...
5873
Joe Cannavo
jpcannavo
Apr 7, 2003 4:57 pm
The lousy keybord in our library at work somehow triple posted... Yet it cant type numbers...my apologies Joe...
5872
Joe Cannavo
jpcannavo
Apr 7, 2003 4:54 pm
... you ... Thanks Nils: the .25" & .8" fields at focal plane agree with the .19 and .six-three (the numbers on this keyboard are messing up!)degree, fully ...
5871
Joe Cannavo
jpcannavo
Apr 7, 2003 4:54 pm
... you ... Thanks Nils: the .25" & .8" fields at focal plane agree with the .19 and .six-three (the numbers on this keyboard are messing up!)degree, fully ...
5870
Joe Cannavo
jpcannavo
Apr 7, 2003 4:54 pm
... you ... Thanks Nils: the .25" & .8" fields at focal plane agree with the .19 and .six-three (the numbers on this keyboard are messing up!)degree, fully ...
5869
Neil Carroll
zzamia2003
Apr 7, 2003 3:36 pm
Hi group, I have been developing this Big Dob Finder/Travel scope combination and wanted to get some feed back from the folks who use large sized dobs. I have...
5868
Nils Olof Carlin
nilsolofcarlin
Apr 7, 2003 2:53 pm
... With a given newtonian paraboloid, the size of the secondary and the position of its placement along the optical path (i.e. distance from primary), in a...
5867
Joe Cannavo
jpcannavo
Apr 7, 2003 1:23 pm
I finally got the answere I needed from an obsession owner at sci.astro.amateur on google. As I suspectd, obsession uses as slightly shorter secondary to focal...
5866
Joe Cannavo
jpcannavo
Apr 6, 2003 11:17 pm
... In-depth questions and quest for answers ... That's what this forum is for ...right? ... Neil, Absolutly! My best bet might be to go with the 3.1 (21%...
5865
Neil Carroll
zzamia2003
Apr 6, 2003 11:08 pm
p.s. (I cant resist) saying that primary diameter x f ratio is a "more precise" equality to focal length is kind of (but not exactly) like saying that 5 x 15...
5864
Jim Miller
jtmiller95746
Apr 6, 2003 10:48 pm
Joe Have you considered just calling the manufacturers and asking them? jtm ... From: "Joe Cannavo" <jpcannavo@...> To: <bigdob@yahoogroups.com> Sent:...
5863
Charlie Starks
cstarsnc
Apr 6, 2003 10:35 pm
Joe, The information you have requested regarding Obsession scopes is not commonly known, nor have I seen it published on any web site. Ditto for Starmaster,...
5862
Joe Cannavo
jpcannavo
Apr 6, 2003 10:33 pm
Neil, I still think we are at cross purposes: In essence I think that you feel that I am oversimplifying. What I am trying to determine,is the comprimise...
5861
Joe Cannavo
jpcannavo
Apr 6, 2003 10:32 pm
Neil, I still think we are at cross purposes: In essence I think that you feel that I am oversimplifying. What I am trying to determine,is the comprimise...
5860
Joe Cannavo
jpcannavo
Apr 6, 2003 9:56 pm
... - ... like ... secondaries ... To Big Dob Group: Please excuse any obnoxiousness on my part. I have perhaps been too long-winded, and therefore unclear. ...
5859
Neil Carroll
zzamia2003
Apr 6, 2003 9:56 pm
Joe, I want to address this line by line also....so here is another post. Lets speak more precisely: Forget for the moment about tubes, low profile focusers,...
5858
Neil Carroll
zzamia2003
Apr 6, 2003 9:35 pm
Wow! I must be using very ambiguous language, I guess I should have majored in english instead of physics... If you majored in physics why are you asking?...
5857
Joe Cannavo
jpcannavo
Apr 6, 2003 8:20 pm
... Wow! I must be using very ambiguous language, I guess I should have majored in english instead of physics... Of course you cant do better than 100%. I am...
5856
Neil Carroll
zzamia2003
Apr 6, 2003 7:07 pm
I do appreciate the mechanical notes you provide, but what I am trying to find out is if the smaller secondary on the Obsession and Starmaster is facilitated ...
5855
Neil Carroll
zzamia2003
Apr 6, 2003 6:57 pm
... I already have the numbers crunched for off axis light fall-off with both a 2.6 and a 3.1", and my numbers concur with both the newt program and Mel...
5854
Joe Cannavo
jpcannavo
Apr 6, 2003 6:29 pm
... actually ... f5 ... real ... NEWT. NEWT is a free design software available here. ... http://home.att.net/~dale.keller/atm/newtonians/newtsoft/newtsoft.htm...
5853
Neil Carroll
zzamia2003
Apr 6, 2003 4:50 pm
... Of course it is, A low profile focuser allows you to get away with an increaesed primary to secondary distance (equivalently, less distance from secondary...
5852
Joe Cannavo
jpcannavo
Apr 6, 2003 4:17 pm
... Of course it is, A low profile focuser allows you to get away with an increaesed primary to secondary distance (equivalently, less distance from secondary...
5851
Donald Clement
donald_clement
Apr 6, 2003 2:18 pm
Isn't the minimum height of the focuser also a factor? Don Clement Running Springs, California http:www.clementfocuser.com ... fact ... size...
5850
Joe Cannavo
jpcannavo
Apr 6, 2003 3:39 am
I have just ordered a 15" F5 PDHQ from discovery. In trying to decide on a 2.6 vs 3.1" minor axis secondary, I am struck by the fact that while discovery uses...
5849
Joe Cannavo
jpcannavo
Apr 6, 2003 3:19 am
... use ... f/4.5 ... John: Let me know how this works out. I also would like to know how you like the optics. I just ordered the 15"pdhq. I haved moved into...
5848
m51john
Apr 6, 2003 12:07 am
The 15" f/4.5 Obsession, and the 14.5" f/4.3 Starmaster both use a 2.6" secondary mirror. I just got a 2.6" secondary for my 14" f/4.5 PDHQ (it has a 3.1"). I...
5847
William Blakeslee
williebluestar
Apr 4, 2003 7:08 pm
... I had a 17.5 inch dob that was optically excellent. Changing the secondary mirror to 3.1 inch from 3.5 inch clearly produced better sharpness on star...
5846
Joe Cannavo
jpcannavo
Apr 4, 2003 1:02 pm
I have just ordered a 15"F5 PDHQ from discovery. Discovery - I think - places the secondary aprox 62.5" from the face of the primary. My question now is on the...
5845
Ken Coates
kennethecoates
Apr 2, 2003 12:28 am
His website says that he is still taking orders for the small and large chairs. He is not accepting orders for finished chairs, just unfinished. I've had one...
