Filters

billythek wrote:

What size filter thread? In most cases, if you are only going to spend $20, I think you are better off without using a filter at all, because it could negatively impact your images (increased flare, reflections, degraded contrast and resolution, etc.). In particular, while UV filters once served a useful purpose for film photography, they do not help digital pictures at all, since there is already effectively a UV filter on the sensor.

If you are looking for a filter for "protection", there is quite a bit of controversy whether that works, as well. But if you are determined to use a filter, it is worth spending a little more to get a good one.