Hi Mick.
Not sure about that one but an F-0.6FR will produce F-0.3 if a 1.4" extension is used to get the FR away from the chip on a toucam.
But when you look at it, it is actually putting the FR closer to the SCT corrector & the chip remains the same distance away
IF your seating the webcam into the focuser all the way on both occasions..
http://webcaddy.com.au/astro/adapter.htm
I could be looking at all this in the wrong aspect though..