Hi Broadville,
Nice to encounter another Sony user. I'm sure many of the others on here will be able to offer you some good advice re: what kind of lens you should use. My camera's a Sony A33 and the regular lens I use is an 18-55mm zoom lens. It's served me well so far. I'm waiting to get the 16mm F2.8 fisheye as having read a lot on the subject a wide angle is something you should invest in for landscapes as it brings that much more into the picture. I can definitely vouch for the polariser. It does reduce reflections. When I first started using it I was amazed just how much it made a difference i.e. clouds taking on more definition against a sky with richer colour. You might want to also consider getting an ND filter.
BW,
NorthStone
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