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Removing built-in Barlow from focuser
Hi all,
I'm considering getting a short tube reflector, but the one in question has one of these blasted barlow lenses built into the focuser. As it is the f/ratio is 7.7, giving an effective focal length of 1000mm. I'm suspecting a spherical mirror, but as this scope will be used for video, could focusing still be a problem at f/3.85 on the small area that is the GSTAR-EX chip?
Mental.
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