In terms of brightness, yes. But you won't get more resolution. Meade took some heat when they used the same misleading analogy when they came out with their...
13154
pensack1
Aug 1, 2005 2:47 pm
Dave, Though I wouldn't discourage you from getting enhanced coatings, just be aware that it is a lot of extra cost, usually. But let's do the math: The...
13155
Gregg
starryskyn
Aug 1, 2005 5:14 pm
Cosmetic, non-functional differences if you ignore or prevent the possibility of warping wood. Most plywoods will not. Aluminum is inedible, will not rot,...
13156
C. Starks
cstarsnc
Aug 1, 2005 5:47 pm
I agree with Gregg in that there is no functional difference, provided there is no damage to either one. The easiest way to set the side bearings is to set the...
13157
gnowellsct
Aug 1, 2005 9:06 pm
Hi Don: I'm waiting for a big dielectric too! One of the things that I was surprised to learn about the enhanced coatings is that they tend to have a modest...
13158
jackhuerkamp
Aug 1, 2005 9:08 pm
There is a third alternative to the “visual observing versus astrophotography” battle – video astronomy. I have been observing since 1968, having...
13159
gnowellsct
Aug 1, 2005 9:09 pm
Some of the big retail outfits sell some of the premium dobs, but I'm hazy as to who sells what. I *think* that Obsession is or was sold by company seven in...
13160
gnowellsct
Aug 1, 2005 9:16 pm
Well I have to take that back. At Anacortes I saw JMI, Celestron and Meade among the dob vendors but no Obsession or Discovery. I didn't see Obsession at...
13161
pensack1
Aug 1, 2005 10:36 pm
Greg, At the molecular level, the finished surface of the polished mirror would look like a piece of coarse sandpaper. The aluminum is typically applied as...
13162
John Mahony
jmmahony
Aug 1, 2005 11:06 pm
There were also concerns that enhanced coatings were more delicate, more likely to be damaged by cleaning than standard coatings. I don't know where that ...
13163
Dale Eason
atmpob
Aug 1, 2005 11:13 pm
Surplus shed. http://www.surplusshed.com/pages/item/m3022.html Dale Eason ... threaded on the inside to accept a 2" male filter thread? I want to fabricate a...
13164
jdsvt1
Aug 2, 2005 2:18 am
Thanks for that insight, I did not think the digital video cams could capture those faint DSOs. ... observing since ... quickly moved to a ... Tasco 3" f/15 ...
13165
Don Wyman
ddwyman
Aug 2, 2005 2:26 am
... When you're ordering a custom made telescope, or boat or golf club or whatever from any small outfit you run the same risks. There's no way to protect your...
13166
jackhuerkamp
Aug 2, 2005 2:56 am
If you look in the Photo section, I have an album. Within it is a folder for the Mid-South Stargaze 2005. It contains three images of challenge objects I...
13167
Alvin Huey
generalragesc
Aug 2, 2005 3:44 am
Sharing my observations of the following three objects. Abell 70 - 22ˇ± f/4.1 (203, 293, 377 and 528x) - This Abell planetary is a bright annular ring with...
13168
David Moorhouse
dmoorhou
Aug 2, 2005 4:51 am
I think it's just a question of the level of abstraction. The orion nebula could be looked at by someone in the space shuttle with a telescope, you could use ...
13169
robert hoffman
roberth_jr
Aug 2, 2005 7:13 am
It actually works out to be 15.5 inches with 88% reflectivity to equal a 15 inch at 94% reflectivity. it's still an approximation. I figured it out the ...
13170
robert hoffman
roberth_jr
Aug 2, 2005 7:13 am
I don't know who you are planning on purchasing your new scope from, but if it is from Dave K. at Obsession, I beleive you have nothing to worry about. Since...
13171
robert hoffman
roberth_jr
Aug 2, 2005 7:14 am
For me, I believe it's a 20" Obsession, because that's what I can haul in my van and have room for my family and luggage, etc. If a 25" Obsession would fit in...
13172
John Mahony
jmmahony
Aug 2, 2005 7:44 am
Right, if only the primary (or only the sec, but not both) has the enhanced coatings. It works out correctly to 15.9 only if _both_ mirrors have the enhanced ...
13173
pensack1
Aug 2, 2005 3:21 pm
John, I, too, read that the dielectric coatings were only perfectly reflective at 90 degrees and that wavefront cancellations occurred at low angles of ...
13174
pensack1
Aug 2, 2005 3:30 pm
The math I'd use would be: R2^2/R1^2 = reflectivity of R2/reflectivity of R1, where R2 is the more reflective. Using that formula, and the 15" mirrors, I get...
13175
Gregg
starryskyn
Aug 2, 2005 4:54 pm
Coatings can be optimised for angles of incidence other than 0* (as in the primary mirror). Making multi-layer coatings for 45* angle on the diagonal is...
13176
William Blakeslee
williebluestar
Aug 2, 2005 6:00 pm
Well, Since I already do this at work 8 to 10 hours a day,(medical imaging) I just haven't been able to get into imaging at home. I'd rather relax at the...
13177
Steven C. Peeters
stevencpeeters
Aug 2, 2005 6:41 pm
DAVE: For some of your same doubts I have my scope on order with Obsession. Dave Kriege is great. I sent him an e-mail last Saturday making a small change to...
13178
billferris2003
Aug 2, 2005 7:36 pm
Alvin, Thanks for sharing your notes on Abell 70, Hickson 82 and Hickson 88 in the 22-inch. I'll have to revisit Abell 70 and try for that background galaxy....
13179
pensack1
Aug 2, 2005 8:05 pm
Gregg, Makes me wonder if the 99+% reflective figures quoted for dielectric diagonals are only for reflectivity perpendicular to the surface, and in reality...
13180
Don Wyman
ddwyman
Aug 2, 2005 8:06 pm
... Oh, BTW, Don is wrong about the ... In many cases the Postal Inspectors will turn the case over to more local authorities. They do not prosecute, they...
13181
chipnwho
Aug 2, 2005 9:27 pm
... That's kind of what I was getting at, though I didn't have time to phrase it very well. Among other things I'm an artist and through the years I've found...
13182
Stephen M. Truitt
stephmac20016
Aug 2, 2005 9:43 pm
See the website of Greg Mort a fine artist and astronomer from Ashton, MD....
