Just to clarify, the used items that it is acceptable to post for sale on this group include: 1) Optics produced by me, 2) Telescopes containing optics...
1135
gumbydad2002
Apr 22, 2013 11:15 pm
A really terrific fellow by the name of Frank is selling his 24" f/3.7 Lockwood/Starmaster on Astromart. Frank is a great guy and bought a 30" f/3.7...
1136
Peter Natscher
prnatscher
Apr 22, 2013 11:23 pm
Bob, I thought you were buying this StarMaster ;) This is my old Starmaster, directly from Rick in 2008. Then it was sold to a person in NJ in 2010. He sold...
1137
gumbydad2002
Apr 23, 2013 1:05 am
Peter, A neighbor offered me his 32" and I decided that it will not be moved and reside in an observing building. Bob...
1138
parabola30
Apr 23, 2013 7:29 pm
I've updated my article "Why aren't my stars round?". In particular, as a result of some client questions and requests, I added to the section that describes...
1139
Bob Hampton
bob.hampton...
Apr 24, 2013 12:11 am
Hey Mike, That's an interesting article! But I notice that you didn't mention the method I use, which is the method described in the instructions that came ...
1140
parabola30
Apr 24, 2013 1:05 am
Bob, That method can work fine if the secondary is centered. However, if the secondary is offset, it won't work. Other misalignments and miscenterings could...
1141
Bob Hampton
bob.hampton...
Apr 24, 2013 5:55 pm
Thanks Mike, I'll give that a try as soon as these damned clouds get out of here! I haven't been noticing any trouble with my collimation, but I might as well...
1142
Bob Hampton
bob.hampton...
Apr 24, 2013 6:06 pm
Hey Mike, I have another unrelated question. I'm preparing to clean my primary mirror - it's been a while and it's looking pretty messy. As you know my scope...
1143
parabola30
Apr 24, 2013 8:26 pm
Bob, My cleaning recommendations are in this article: http://www.loptics.com/articles/mirrorcare/mirrorcare.html It's best to rinse off loose dust/dirt before...
1144
rrsteudtner@...
rrsteudtner...
May 1, 2013 9:31 pm
Hi Mike I finally had an opportunity last night to test out my Orion Dobs with the newly refigured 12" primary mirror which you provided me. Observing...
1145
randallcarlson4000
randallcarls...
May 9, 2013 7:19 pm
Mike, What's the fastest 28" mirror that can be made for visual observing. Is it f2.8? How about on a 30" or 32"? How long a waiting period is it to get one of...
1146
parabola30
May 10, 2013 2:28 am
Randy, The limiting factor for f/# is the performance of the coma corrector. I usually recommend f/2.8 as a lower limit, because the Paracorr 2 still performs...
1147
randallcarlson4000
randallcarls...
May 10, 2013 3:39 am
Mike, My observing is only on galaxies at 250x-350x. Do you still need the Paracorr at this magnification? Can you push the mirror faster as long as you never...
1148
parabola30
May 10, 2013 3:37 pm
Randy, ... I recommend Paracorr 2 use at all times for telescopes under ~f/5 because it improves the sharpness of images over the whole field. This is...
1149
randallcarlson4000
randallcarls...
May 10, 2013 4:07 pm
Mike, Why does it seem to be such a feat to make a RC telescope. Can't you just drill a hole in the mirror and be done with it? This would solve all the...
1151
parabola30
May 10, 2013 4:56 pm
Randy, ... No. The primary is hyperbolic, not parabolic, and requires more labor to make, not to mention the added complication of working on a mirror with a...
1153
Randall Carlson
randallcarls...
May 11, 2013 9:45 pm
Mike, On a 30" or 32" mirror, is f2.8 also the reasonable limit. If the mirror blank is thicker on these, can you go faster with less added cost? Have you ever...
1154
parabola30
May 11, 2013 10:14 pm
Randy, ... Yes, f/2.8 regardless of size. No, thicker glass costs more, and doesn't make the work any easier. I like 2" thick for 28" and 30", and slightly...
1155
parabola30
May 13, 2013 3:37 pm
Hi, I've posted a couple of new installments of "In the Shop" about a 42" mirror and a rather unique photo opportunity with an uncoated 50": ...
1156
parabola30
May 14, 2013 5:09 pm
This thread is being started to begin a discussion of large, fast intruments. Two potential clients recently contacted me about 28"-32" mirrors at f/3 or...
1157
fast_mike28
May 14, 2013 7:50 pm
Hi, Mike I'll start with a few links from cloudynights. These are just some that I have bookmarked over the years. I will try to add a few new topics (maybe...
1158
John Pratte
astrocrafter
May 14, 2013 8:36 pm
Mike Webb likes his JPA/Lockwood 25" f/3. He had a 25" f/5 previously. I compared his scope to my 25" f/4 Lockwood and could not see any difference in the...
1159
parabola30
May 15, 2013 11:17 pm
Mike W./John, Thanks for the feedback below. The specific comments such as "The Trapezium had moments of 8-9 stars" are great data points that actually...
1160
fast_mike28
May 16, 2013 7:04 pm
I've had my 28" f/2.75 for over a year and a half now. I've used it over 100 times with 100's of hours. I'm very happy that I went with such a fast telescope....
1161
fast_mike28
May 16, 2013 7:10 pm
Eyepiece selection in a fast scope was one of the concerns I had prior to receiving my telescope. This is a short review of what I've seen and noticed while...
1162
parabola30
May 18, 2013 5:29 pm
Mike, Thank you for your time and effort and valuable information regarding your fast telescope. I really appreciate your sharing the information with us. ...
1163
parabola30
May 20, 2013 3:21 am
Hi, Here's my article about our visit to NMAV in April: http://www.loptics.com/articles/clark1/clark1.html I'm hoping to be back right after Okie-Tex this...
1164
daviddench
May 21, 2013 8:05 am
Sorry if this is not the place to post this but I have a query about Mike's Dob mounted classical cass with the tertiary mirror. In particular about the...
1165
dsvanderbilt
3:56 pm
Hi Mike, Could you please email me or let me know what is a good time/day to phone you? I've a question regarding a 20-inch blank that has already been hogged...
