Re: [ATM] Betr.: 48" Dob at OMI

[Alexis Cousein <al@sgi.com>]

Harro Treur wrote:
> 
> Better put some eyeglasses on when viewing M42 from Texas...
> 
Need I remind people that you cannot increase the surface brightness
of an extended object with an afocal system like a telescope plus
eyepiece with respect to that of the naked eye view?

In other words, you can't make M42 any brighter (is surface brightness)
than when seen with a 7mm exit pupil eyepiece in a 16" Dob (or indeed
any brighter as far as surface brightness is concerned than what
appears to be just next to Theta Orionis with the naked eye).

All you can do is to make the brighter part around the trapezium
fill the entire field of view (which of course is very much brighter
than when you only see it as smaller and surrounded by darker parts,
but you won't need sunglasses for it.

It's enough to really mess with your dark adaptation, though.

-- 
Alexis Cousein                                  al@sgi.com
Senior Systems Engineer/Solutions Architect     SGI/Silicon Graphics
--
<If I have seen further, it is by standing on reference manuals>

_______________________________________________
ATM mailing list http://www.atmlist.net/