A question about flocal lenghth. [Archive]

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White Rabbit

14-10-2011, 04:57 PM

Hi Guys.

Can someone help me calculate, or should I say can somone calculate for me the focal lenght of my scope please.

I have a refractor that is 714mm focal length but I have a 0.8x field flattner/focal reducer.

Thanks

White Rabbit

14-10-2011, 05:00 PM

Would I be correct in thinking 571.2?

Alchemy

14-10-2011, 05:09 PM

Yep sure is.

Neil

14-10-2011, 05:16 PM

:thumbsup::DI second that.:)

Barrykgerdes

14-10-2011, 05:23 PM

Tecnically the focal length will be changed by .8x for calculations of FOV but using a field flattener on the focuser will not change the physical length of the focal path by more than a few centimeters.

Barry