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Re: [ATM] [atm_free] Rush into F3.5
Ukyo,
If you do not want to be forced to produce a hyperbola, there is a 0.73x
coma corrector/reducer that is 2" in diameter. It is made for parabolas as
fast as f3.0. You can see the technical information about this corrector
below:
http://www.astrooptik.com/sonstiges/NewtRedNew/ReducerNew.htm
Do NOT contact Philipp Keller for additional information. Contact Egon
Doberl from ASA at the below e-mail address for questions and/or ordering:
egond@gmx.at
If you are using a small CCD chip, smaller than 12mm square, switching
between the two systems you outline will be less stringent than if you plan
to use a 25mm x 36mm chip. Either way though it is not a trivial task
aligning such fast systems with a diagonal in the mix.
If you want the most visually, you should use a coma corrector. TeleVue
sells a very nice visual corrector for this purpose, the Paracorr.
The above correctors would give you the best performance for each emphasis
but they come at a price. Everything does...
You might start with a question for yourself. Which do you plan to use it
for more: visual or imaging.
If imaging is more important, then I would suggest you optimize the system
for the 0.73x reducer/corrector and imaging. Then use the system with this
secondary visually to see if the views meet your requirements. Again, if
you want the most visually, use a coma corrector visually as well. Not
having to change out the secondary and leaving the system fully collimated
will make life SO much easier for you.
Thank you.
Sincerely,
Shane Santi - President
Dream - Telescopes & Accessories, Inc.
http://www.dreamscopes.com
610 - 365 - 2833
At 04:02 AM 11/15/2006, you wrote:
>Or maybe I can make 2 sets of diagonal for a hyperbolic mirror+corrector,
>1 set with minimize size for visual (10% obstruction), another set for
>photograph (18.3% obstruction), and the system is F2.8 if the mirror is F3.5.
>
>The most difficult thing is figuring a hyperbolic mirror...
>
>Best Regards,
>Ukyo Chen
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