Re: [ATM] 32" Focal ratio

["Ukyo Chen" <ukyochen888@hotmail.com>]

Hi Scott,

Basically a fast F ratio will reduce the exposure time, as well as the tube 
length and weight.
I suggest you use parabolic mirror + wynne corrector. commercial coma 
corrector are not designed specially for your system and the performance may 
not as good as you can.

Below is a 20% obstruction telescope that perform diffract limit image in 
whole 24.6x24.6mm area. You can put secondary right behind lens 2 so that 
camera or eye pieces can be easily connected after lens 3.

If you do not need to connect eye pieces, please let me know and I will 
modify the design to get less obstruction.

Best Regards,
Ukyo Chen

F/5 32" wynne corrector
SRF      RADIUS      THICKNESS   APERTURE RADIUS       GLASS  SPE  NOTE
OBJ  0.0   1.0e+20   4.3633508207e+17             AIR

AST  -7135.270890953675 V -3000.0   407.0 AS   REFL_HATCH   *

  2   -160.6112693212592 V -15.0   77.8465641180188 S           BK7 C
  3   -282.4400424991707 V -40.0   74.2797145556817 S           AIR

  4   -427.5044558225438 V -10.0   65.2910476243541 S           BK7 C
  5   -144.0836019042825 V -500.0   63.2897662600067 S           AIR

  6   -226.6123202207288 V -10.0   25.2464843501938 S           BK7 C
  7   -655.2293854027363 S -57.6514303221301 S 24.3649768490518 S           
AIR

  8   0.0   0.0   17.7588378402554 S           AIR



>From: Polaraligned <polaraligned@optonline.net>
>To: aplanatic@aol.com, atm@atmlist.net
>Subject: Re: [ATM] 32" Focal ratio
>Date: Mon, 01 Aug 2005 20:17:56 -0400
>
>>Hi Scott,
>>
>>What is the largest camera you will be using with the scope?  Are you 
>>figuring the mirror or is someone else?  Will you be buying (or making) a 
>>focal reducer?  How picky are you about the images at the edge of the 
>>field?  Do you plan on doing mosaics?
>>
>
>
>Probably a KAF 1001 with a 24.6 x 24.6 mm size.  24 um pixels.  It's
>pixel size is a good match for the long focal legnth without binning.
>Plan on having someone else make mirror.... Buying a coma corrector....
>Well, of course I would like the best possible images to the edge of field,
>and I can't rule out mosaics.  Am I asking too much?  How will this scope
>compare to an RC?  Oh, and the original question: Is a longer f ratio going
>to help me achieve better images, even with a corrector?
>
>Opinions appreciated,
>
>Scott
>
>
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