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Having an 18" diameter 2" thick pyrex mirror I can only echo Mark Suchting's comments about these mirrors in another thread. I think a 2" thick 16" diameter chunk of BK7 glass is going to have "MAJOR" cooling and thermal equilibrium issues. My 18" pyrex mirror can often take 4 to 5 hours to stabilise properly and deliver 1st rate planetary views. A BK7 mirror could take all night. Whilst the mirror substrate is relatively unimportant in apertures up to 12" it can matter in this aperture class. Just be aware of this before you "dive in" and drop your hard earned cash.
CS-John B
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