Re: [ATM] undercorrecting?

["laurence vincent" <laurence.vincent@club-internet.fr>]

hello
I already heard this assertion on behalf of proffessionel, to check it is
more difficult.
Look the work of Mr Wolfgang Rohr
http://www.astro-foren.de/showthread.php?t=6454
http://rohr.aiax.de/strehl-verb.htm
Franck grière
www.mirro-sphere.com

----- Original Message ----- 
From: "J H M Gastel" <jhm.vangastel@wanadoo.nl>
To: <atm@atmlist.net>
Sent: Thursday, August 03, 2006 8:57 AM
Subject: [ATM] undercorrecting?


> Sometimes the topic of deliberately undercorrecting large mirrors comes
up. On a Dutch mailinglist someone writes undercorrecting is necessary,
because a mirror, even a mirror cooled with fans, will never reach
equilibrium because of radiation of heat from the alumiumized surface of the
mirror into the kosmos. Reason why the face of the mirror will always be
cooler then the back side, which will deform the mirror. Maybe there is some
radiation, but I can't imagine that, in the case of a well cooled mirror
(well placed fans of sufficient capacity)  the effect is so large that it is
necessary to leave a large mirror undercorrected. Did I miss something?
> Jan van Gastel
> http://home.wanadoo.nl/jhm.vangastel/Astronomy/
> _______________________________________________
> ATM mailing list http://www.atmlist.net/
>

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