Depends on 3 things: 1: How much can you lift repeatedly? 2: Thermal control. Thick mirrors take longer to cool and usually require active thermal management (fan) 3: Support. Thin mirrors need perfect support from their mirror cells. Each is capable of superb imagery, if you observe all the caveats. Once you reach a certain aperture, thin is the only option. In small scopes, go with thick unless you decide to flex it ala Kelley/Adler. For an 18", though, my personal choice would be thin (I'm getting old...) C. --- UTAHDEB@aol.com wrote:
What are the advantages of each and which ones to your guys/gals prefer? Is there a visual advantage to a thicker mirror or are they about the same?
I was thinking of upgrading to an 18" dobsonian reflector. The StarMaster 18" telescope seems a little more portable than the 18" Obsession. I can't lift the Obsession 80 lb mirror box. I'd need a trailer or truck to haul the 18" Obsession. Which would you guys/gals pick and why?
Debbie
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