FreeLists / az-observing / [AZ-Observing] Re: Mars Is Not "Too Bright"

["Tom Polakis" <tpolakis@xxxxxxx>]

Jack wrote:

> I wonder if that's what it mostly is then. When an aperture mask is 
used on
> a large telescope the view is usually improved because on par large 
mirrors
> are just not that great. Cutting off the edge and bad parts of the 
mirror
> would give a surprising improvement, esp. on planets. At star parties 
you
> continually hear from light bucket owners 'well the seeing isn't that 
great
> right now'. It's amazing how quickly the seeing improves in the time it
> takes to walk to another telescope.


Yep, I complained about "seeing" and "thermal effects" harming the images 
in my 20" for five years before the figure was touched up by Mike.  The 
definitive blow was dealt during a night at Arizona City, when the image 
of Saturn through a 4.5" SkyQuest was just killing my behemoth 20".  That 
night, Mike described the hills and valleys in the figure of the mirror 
using nothing more than a defocused star.

I should have emphasized in my post that the underlying assumption of 
promoting full-aperture viewing is that the optics are good.

Tom

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