Hi John I saw this mirror at NEAF. I think it was a "HOT" product in 2009 in S&T. George F5 ??? Sent from my Verizon Wireless BlackBerry ... From: John Mahony...
19906
parabola30
Jan 3, 2011 5:49 pm
Hello, Speaking from direct experience.... Dream Cellular is currently the only vendor that I will deal with for cast cellular blanks. Their product, based on...
19907
pensack1
Jan 4, 2011 1:14 am
Dave, I'm left eye dominant, so I look through the finder with my left eye. However, it doesn't have the visual acuity of my right eye, so I observe with the...
19908
tsulmer1
Jan 4, 2011 1:26 am
Don, Yes, I'm talking about rotating the entire truss/tube structure. I agree that collimation would not hold by only rotating the top (and I don't want to...
19909
atmpob
Jan 4, 2011 4:15 am
I hope people don't mind me pointing out that the original question is no longer being addressed by this thread. It was not about what side the focuser should...
19910
tsulmer1
Jan 4, 2011 6:30 am
I prefer the as delivered position (diagonal) as I also feel it offers more comfortable viewing at a greater range of altitudes. Tim in Calgary...
19911
pensack1
Jan 4, 2011 7:26 am
Dale, That's the dob dilemma. At high altitudes, the side position is best. At low positions, a more topside focuser position is best. It depends on the size...
19912
Malco Precision
mrmalco1
Jan 4, 2011 12:49 pm
Dale, I guess it depends on the size of the scope. When I had a 12 1/2 f4.8 I had the focuser in the 60 deg position, but now I have a 20" f5 Obsession and I ...
19913
gersatx91549
Jan 4, 2011 3:49 pm
Can anyone tell me the signs that would indicate when a large dob mirror would need to be re-coated? Or is there a particular age when a mirror should just be...
19914
John Mahony
jmmahony
Jan 4, 2011 10:13 pm
On nights of very good seeing, I can tell if someone stands in front of the scope under the light path. But that's full body heat rising into the light path,...
19915
John Mahony
jmmahony
Jan 4, 2011 10:21 pm
Zambuto is frequently considered the best. I'm surprised to see that he is now selling to the public. Demand for his mirrors is so high that in the past, he ...
19916
Bob Bunge
bungerob
Jan 4, 2011 10:58 pm
My favorite subjective test is to look at the sun through the _back_ of the mirror. Assuming the back surface of the mirror is ground frosted and the mirror...
19917
atmpob
Jan 4, 2011 11:13 pm
I see that the answer depends upon size of scope. Much like my 16 F5 I think the 18 UC requires about 1 step for most people when at the zenith. So would...
19918
John Mahony
jmmahony
Jan 5, 2011 3:57 am
Put a bright light behind the mirror (actually it doesn't have to be that bright- just brighter than the surroundings- I've used a red flashlight at night). ...
19919
John Mahony
jmmahony
Jan 5, 2011 4:01 am
Wouldn't the sun be too bright for this? Metal-coated solar filters reflect 99.999 of sunlight (actually some is absorbed- no surface is that perfectly ...
19920
Fernando Rivera III
fernandorivera3
Jan 5, 2011 2:15 pm
Hi, John Thanks for responding to my question. Really appreciate it. Regards, Fernando ________________________________ From: John Mahony <jmmahony@...> ...
19921
Big
bigdob20
Jan 5, 2011 6:12 pm
One other criteria is to look for sleeks in the coating which can appear after cleaning. Ussually compressed air is enough to remove loose particles, but...
19922
Stephen M Truitt
stephmac20016
Jan 5, 2011 6:29 pm
I have a number of blotches but no sleeks and the images seem good, but I may have gotten used to a gradual degradation....No really sure whether to send the...
19923
George Andrew
geodandrew
Jan 5, 2011 8:58 pm
I always herd that Zambuto was one of the the best as well, but I thought that they didn't make large mirrors. Like, say a 20" F5 or 24" F?. George ...
19924
George Andrew
geodandrew
Jan 5, 2011 9:04 pm
I guess I should have looked at the website. :-( George ________________________________ From: George Andrew <geodandrew@...> To: bigdob@yahoogroups.com...
19925
Howard Banich
hbanich
Jan 6, 2011 1:26 am
Zambuto has an excellent and well deserved reputation but Kennedy and Lockwood make equally superb mirrors, and don't forget Swayze. There are several other...
19926
Roy Diffrient
roy_diffrient
Jan 6, 2011 2:37 am
Well, I guess the good news is that this test shows the coating on my primary is in good shape. The bad news is that the top of my big dob burned up while I...
19927
Roger Greenwood
astrocrumb
Jan 6, 2011 11:41 pm
Well, I've given it much thought and listened to all the feedback. My impression was "why is the focuser there?" upon using it the first time. The owner I am...
19928
gersatx91549
Jan 7, 2011 2:16 am
Thanks to all of you for your feedback. As usual, you've been really helpful. GT...
19929
james soboleski
jwsblue1
Jan 7, 2011 8:18 pm
Carl made me a 20 inch f5 last year. I think he can assist you. He does a great job and customer satisfaction is job 1 for him. I don't think you could do...
19930
fernandorivera3
Jan 11, 2011 3:21 pm
Hello, I just found out about big Dob scopes being made from "down under" and have "Obsession style." They are custom scopes by Peter Read, and the web address...
19931
paul_winalski
Jan 11, 2011 4:22 pm
I have had the opportunity to use Peter's SDM telescopes on observing trips to Australia. They are excellent instruments. -Paul W....
19932
Dick
rmcarner
Jan 15, 2011 2:13 pm
... I am curious how you arrived at this opinion. Statistical sampling method? Or, simply acknowledging the number of passionate testimonials with respect to...
19933
Big
bigdob20
Jan 16, 2011 4:00 am
I must agree with Dick that there are some excellant opticians out there, both amature and professional. Quiet francly, I have never heard of Zambuto, but...
19934
Kurt Maurer
cbp704
Jan 16, 2011 3:06 pm
... Never heard of him. Darn it. My most prized possession is a Jerry Wilkinson mirror. My next most prized possession is a Steve Dodds (Nova) mirror. I have...
