[ATM] Re: 40" mirror

["Mike Conran" <mike@guidesys.com>]

Well folks, probably the big reason people attempt these large projects are 
the picturelike views of deep sky objects to be had.  As an example, when 
you look at the Veil Nebula with proper filtration the thru a 30 inch scope, 
the contrasts, brightness, details and size of the object kinda takes your 
breath away.  It's about capturing photons and aperature fever.  It's a 
sickness but a noble sickness  :)

Mike Conron 

Jerry B. Hillman writes: 

> Hi Jay,
> I can set my 15" up in about 5 minutes.  That is how long it take me to put
> the two wheel dolly under it and wheel it out of the garage into the yard.
> Of course, if I want to take it anywhere, I have to put it in the back of my
> pickup. That circumstance hasn't come up.  I have nice dark skies right here
> in my back yard. I had the electric company remove their supplied
> yard/security light and I put in one of my own so that I could turn it off
> if I wanted to. The only time the lights from Houston bother me is when it
> is cloudy ovrer Houston but clear here.  That just means a portion of the
> southern sky is light plouted. 
> 
> Obsession discontinued their 30 " scopes.  They actually built a couple of
> 40" scopes. 
> 
> I have gotten a lot of negative feedback on this project.  You are right. I
> have to be insane.  After having so much trouble with my first two mirrors,
> even I wonder why I still try. 
> 
> As far as being 4" thick.  I don't want to do another thin mirror.  Most of
> the last two years were investing in a project that ultimately was a
> failure.  All of the problems can be directly traced to the thickness of the
> glass.  A 40" is going to be nearly impossible under the best of conditions.
> I don't want to place more hurdles in my path just to make it cool quicker.
> This monster isn't going to be stored in the house anyway.  Most of the time
> it will be in an observatory out in my pasture. So the only temperature
> problems will be the fluctuations during the night, which everyone has to
> deal with.
> No scope ever reaches equilibrium unless it is stored in a controlled
> environment. 
> 
> Clear skies, Jerry 
> 
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Mike Conron 
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