Gday Ken
Just for info, the original Meade 6.3 units sit at about 110mm,
but about 6 years ago, they changed the design and the new ones
focus at 45mm.
Lots of people who understand optics better than i do argued over this for a while and suggested it may be a bad batch, but eventually they agreed it was in fact true.
The latest Meade literature also suggests 45mm is optimum for the later units
http://www.meade.com/accessories/premium/index.html
To test the units, you need to focus an object at infinity to see what the true FL is ( use the moon or a light about 50feet away and focus the image on a wall or sheet of paper )
The old 6.3s have about 260mm true FL and sit about 110mm from the chip.
The new ones have about 130mm tru FL and sit about 45mm from the chip. ( ie unusable visually )
Andrew