As Mars gets smaller filters really help. Tonite with my 10" f4.6 and 4mm eyepiece for 292x, could see dark zones along top half of planet, but could not recognize area, so tried filters.
The 2 best were Vite msg and FLD. Now could see what was looking at, Solis Lacus and the east coast of the area bordering it.
The next 2 best filters were
SV Bony moon filter rumored to be identical to Baader Contrast, and real Baader MSG.
According to my chart Mars is now 16 seconds of arc diameter.
Not much time left, sure is shrinking fast.
Arizona- where the sky's are not cloudy all night.
Triple lensed fracs are so yummy when looking at planets.