Re: [APML] A beginners question

["Eric Z. Beard" <ericzbeard@yahoo.com>]

I think it's going to be really difficult to get decent results with this lens.
 f/8 means you will need really long exposures, even if you are pushing a film
to ISO 800.  And at 500mm focal length, you'll need a top-rate mount and
probably an autoguider.  I'm not sure about the quality of those mirror lenses
either.

Piggyback photography is usually done with shorter, fast lenses, so you don't
have to worry about tracking so much, and you can usually get pretty good
quality without breaking the bank.

EZB

--- "I.J Jordan" <ian@sunhouse.plus.com> wrote:
> Hi All
> 
> Being a total newbie to astrophotography,and still in the process of 
> getting the bits and pieces together I would appreciate some thoughts 
> on something.
> 
> Apart from their being on perhaps the "slow" side:on average f8,are 
> there any other inherent problems involved in using a mirror telephoto 
> lens for astrophotography when piggy backed on a telescope.I feel that 
> there maybe because after a look through the archives it would seem 
> that although a number of people achieve some stunning results by piggy 
> backing a camera and telephoto lens,I see no mention (unless I am 
> looking in the wrong place) of the use pf "mirror" lenses.
> 
> My reason for asking is that my wife uses a 500mm f8 mirror lense for 
> her wildlife photography,and I wonder if it would be practical for me 
> to use it during the winter for astro-photography.
> 
> Looking forward to any thoughts or suggestions
> 
> Ian & Linda Jordan
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=====
Eric Z. Beard
http://www.honeydewphoto.com/eric
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