Occulting Eyepiece, observing Phobos and Deimos

This morning a friend and I were observing Mars (with my friend's Takahashi
TOA 130 - a wonderful scope!), and got talking about trying for either or
both of Mars' moons, Phobos and Deimos. He said that he had once attempted
to add an occulting bar to a UO orthoscopic, but that he wasn't successful
in positioning the bar at the focal plane. After I got home this morning, I
unscrewed the barrel from a 7mm UO ortho, and discovered that the focal
plane is up inside the housing which holds the lenses, .100" from the bottom
of two opposing slots in a retaining ring. These slots are each about .027"
wide, and the ring is just over .400" in diameter. I cut a piece of credit
card which is .030" thick into a strip .400" wide, and then cut a piece of
that so that it protrudes .100" up into the housing. The thickness of the
credit card material is such that it stays put when forced into the slightly
smaller slots in the retaining ring. The edge of the card is nicely
positioned at the focal plane, and seems to be of a thickness sufficient to
block out Mars in any scope I have access to.

Now, has anybody here ever observed either of Mars' moons? Does anybody have
any tips on observing them?

BTW, Mars was very nice with a 3mm Radian (333x) and a W85 salmon-colored
filter. Not a tremendous amount of fine detail, but enough to keep us
consulting Mars Previewer. Also, I wonder if the dust storms are not
completely over. We briefly observed Venus and Saturn as well, with Saturn
surprisingly nice for being as low in the east as it was.

Dennis


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