It really depends,
I currently use a Genesis camera with 9uM pixels
and image at f/10 and 2x2 binning and get great results
you don't have to image at 1x1 binning so you have the added
flexibility of combining the two (binning and f ratio) to get
the pixel size you want. the 2 pixel is not a rule it a guideline
based on the average seeing of sites.

If you want to check of combinations I have a spreadsheet
that I did to do this with different optical configurations
at http://carroll.dynip.com/other/ccdpss.htm

Ultimately I am going to be using a 6.3 and 3.3 reducer as well
I have the 6.3 already.

hope this help some

Doug

-----Original Message-----
Doug David
Sent: Wednesday, May 30, 2001 1:29 PM
To: mapug
Subject: [M]: 8" LX200 and Starlight Express MX7-C


Hi,

I have a Meade 8" LX200 and am considering a Starlight Express MX7-C for
astrophotography. My question is, for an 8" LX200, which focal reducer would
perform better for deep space pictures, the f3.3 or f6.3? Pixel size of the
MX7-C is 8.6 x 8.3uM. If I am correct in using the following to obtain 2 arc
seconds per pixel (formulas from Starlight express)

F = Pixel size * 205920 / Resolution (in arc seconds)

In the case of the MX7-C and a 2 arc seconds per pixel resolution:

F = 0.0082 * 205920 / 2 = 844mm

For a 203mm (8") SCT, this is an F ratio of 844 / 203 = F4.15, which falls
right in the middle of the F3.3 and F6.3 reducers. So which one would
perform better?

Doug

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