From the details Alvin has brought out about the red-shift to about 530nm it would seem the Johnson/Cousins V filter may offer improved contrast for this object over the Sloan G given a large scope. The Sloan G is 150nm wide at that point with near 100% transmittance so it wins with transmitted light (important here of course). The Astrodon version of the V filter is by far much narrower in the 530 area and is tapering off in this range. The V is about 50nm wide but sloping off from it's peak of 94% at 520nm, 91% at 530nm, 86% at 540nm, 83% at 550nm where Sloan G drops like a rock. At 10% transmission the V is 140nm wide which approaches the Sloan G bandwidth of 50nm but is well down.
Marko
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