Quote:
Originally Posted by Ambermile
Well - you tell me what an OCS is and I'll let you know...
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While not an expert...I do have a Denk Big Easy Binoviewer and it seems to work fine in my reflector and refractor...from the OPT website a comment on the Denkmeir OCS...
" Product Information - About the Denkmeier 1.25" OCS
The "Optical Corrector System" (OCS) is a peripheral optical system that allows the Deepsky Binoviewer to reach focus in a telescope where the focal plane formed by the primary mirror or lens remains in a fixed position. While some telescope designs like Schmidt-Cassegrains have the ability to "push" the focal plane forward by moving a spherical primary closer to the concave secondary, the majority of telescopes cannot perform this maneuver. Therefore, a means must be implemented to place the focal plane far enough forward so that the eyepieces placed in a binoviewer can form a focused image where your eyes can intercept this image.
In the past, a barlow lens was used. A standard barlow lens will in fact allow the focal plane to be accessed for viewing with a binoviewer. However, the magnification when using a typical 2X barlow ends up being more like 4X when implemented for this purpose. This means that even a 40mm eyepiece would behave like a 10mm. This situation has prevented the proliferation of binoviewer use for "all of the time" observing, especially for deep-sky work.
This is why our patent-pending, multi-purpose 1-1/4" or 2" OSC has such important implications for the advancement of bino-viewing. Now, the OCS allows the binoviewer to operate at almost true power. Low power applications are now possible!
In the past, big Dobsonian owners cut their poles down or had two focusers with one in a much lower position. A much larger secondary mirror is needed for this to work. This is because the light cone is intercepted by the secondary when it is wider. The expense and hassle of rigging up such a dual configuration made it impractical and expensive. Furthermore, coma from the primary mirror is corrected with the use of the OCS. So, it is clear that there are many advantages to be realized through use of the OCS."
Hope this helps!
) although it does sound like at least *somebody* listens to what people are asking for out there!
