Thinking about it, the amount of travel gained without the diagonal is probably closer to 75mm. Plenty, even for a digital SLR. Going "on the cheap", one could use one of those "digital eyepieces" and make an adapter that allows it to slide INSIDE the 2" focuser drawtube. Presto- all the "in" travel needed; instant video astronomy for the masses. Reminds me of when I shot video of SL-9 impacting Jupiter. Fun project. On Tue, Jun 9, 2009 at 10:59 AM, Chuck Hards <chuck.hards@gmail.com> wrote:
Even if "in" travel is needed, all you have to currently do on the Grim is remove the 2" diagonal. That gives you 40mm-50mm of in travel, and eliminates 25% of the throughput loss to reflection. The view is reversed left-for-right in that instance, but that's not a problem. Just like viewing through a SCT with a star diagonal. Easily corrected on the computer.