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...
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...
Cosmetic, non-functional differences if you ignore or prevent the possibility of warping wood. Most plywoods will not. Aluminum is inedible, will not rot,...
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...
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...
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...
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...
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...
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 ...
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...
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 ...
... 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...
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...
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...
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 ...
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 ...
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...
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...
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 ...
John, I, too, read that the dielectric coatings were only perfectly reflective at 90 degrees and that wavefront cancellations occurred at low angles of ...
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...
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...
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...
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...
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....
Gregg, Makes me wonder if the 99+% reflective figures quoted for dielectric diagonals are only for reflectivity perpendicular to the surface, and in reality...
... 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...
... 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...
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