Aperture to resolve Cassini Division into gap?

I'm sorry I'm full of questions this week (or perhaps full
of s__t :-().

I've been testing this new gadget someone on the Tele Vue eGroup has built for me, a Focus Lever that slip onto my focuser which allows me to focus without or little shake and act as a fine focuser due to the lever and virtually enlarging the knob.

First of all, let me define dark black "gap" as a dark thick line that has a detectable **width**. The Cassini Division was as clearly shown in Roland Christen's sketch from his 10" AP MCT as (quite a) large **gap**.

Anyway, I've been wanting to try out Jeff Medkeff's article on high magnification but found focusing a real pain until now. And I've been trying to find out about the Cassini Division; for up until last night, I've seen it as a dark line with no width.
http://roboticobservatory.com/jeff/observing/why_high_power.htm
So tonight at 293x, the Cassini Division appeared so sharp. Uping the ante to 352x and at 440x I believe I could see the division as dark thick line (like a very small gap) around the ansae. Oh, seeing was steady tonight. But at 110X/inch, I'm very cautious and am not sure if this is possible or am I just seeing diffraction effect. I think I haven't seen this before because I could never got it
focus properly due to the shake and lack of fine focusing at this high magnification. I now regretted I didn't have time to do a sketch last night :-(.

My question is: can the Cassini Division be resolved into a *small* gap with a 4" aperture? Or was I just seeing larger "airy disc"? If the answer is neah and yeah, then what is the **minimum** officially accepted aperture that could resolve the division into a **small** but detectable gap (just large enough without having it being so wide as to be able to drive a truck through that it ;-).

Thanks,
Ron B[ee]

Hello Ron!
Well.... I think we all could have our "own" perception of what a "GAP" could be... some might define it as anything wider than a HAIRLINE... while others might have a HIGHER EXPECTATION...

While I was down at the WSP 2003, I pushed Saturn to 500x one of the steadiest nights (10" LX200GPS here...) and it definitely shows as a BIG GAP to me... (but then again, at 500x it better show as more than a HAIRLINE!)

I think at 200x-300x you can already see it as a gap, but it all depends on "What you personally define as one..."


My .02 cents, well spent...


Clear dark skies my friends!


Ivan

Maybe I'm confused, (or misremembering, I basically missed Saturn this year because of the weather) but in my TV-102, on nights of extremely good seeing, the Cassini division appears wider at the outsides of the rings than it does in the middle, and it tapers visibly between these two extremes. It would be hard to convince me I am not seeing resolved width in cases such as these.

In normal weather conditions, not this year, I may be spoiled with regard to seeing. I live at the end of a 4-mile-long peninsula, with water essentially all around. Maybe unusually good seeing combined with good optics makes some of the textbook numbers too conservative?

Steve