Oh, I almost forgot to finish up with the filter recommendations, I’ve already covered Tiffen (3/7 post below) and B+W, (3/11), this time it’ll be Hoya. I just noticed all my Hoya filters are made in Japan by Tokina! I use an HMC super UV(0) 62mm or 77mm on the Sony CZ 16-80mm for protection in dirty or wet environments; the filter is a little pricey but I didn’t want to compromise any image quality by using something cheaper, although I’m not sure if it offers better image quality than a cheaper model.
One thing you can do to help reduce the cost of filters for Sony lenses is buy only 77mm, and use a 62mm-77mm or 55mm-77mm step-up ring (or whatever size your threads are) for lenses that use smaller filters. The downside to this is the original hoods won’t fit, but with zoom lenses, hoods don’t work very good anyways. The step-up rings shouldn’t cause any light fall-off because the filter is so much bigger than the lens’ original filter size.
As I pointed out in the 3/11 post below, I keep a Hoya HMC ND8 filter for slowing action, such as water in bright conditions. A ND8 is 3 stops of light loss, which should be enough for most conditions, but if you’re trying to blur the subject background by using a large aperture and trying to keep a slow shutter speed, you’ll probably need to add a ND1.8 which is 6 stops, for a total of around 9 stops, that would slow the shutter speed significantly. Nine stops of light is the same as going from a shutter speed of 1/500 to 1 sec.
None of the filters mentioned above are “thin” type, which are more expensive, but thin filters are not normally necessary unless you’re stacking filters, and/or using the widest aperture and already have light fall-off issues from just the lens. Light fall-off or “vignetting” doesn’t bother me, but everyone has different peeves.