Eric,
Sorry, I hope I didn't stumble across an (another) idiom with disparate meanings, there!
I've learned the hard way that some of my American phrases do NOT translate the same! Someone, please tell me if 'loosey-goosey' has profane implications, here...so I don't (again) insert my size 12 American feet into my mouth at some gathering. [It's common for an American, after a good meal with friends, to lean back in the chair, pat his newly full stomach, and comment appreciatively and loudly "I'm stuffed!" It means (to us) that the food was too good and we ate too much. But, at a recent dinner with some very new Australian colleagues and friends, it precipitated a completely unintended reaction from the Australians at the table....need I say more?]
Just meant that the coma-free zone in an f6 is substantially larger than in an f5 or f4, and an autocollimator is probably wasted money on an f6 compared to an f4 'scope...it'd be hard to identify the benefit of its use.
Eric, I would never insult your telescope. Our scopes frosted together a few weeks back, after all.
Regards,
Scott