HOYA 58mm LINEAR POLARISING FILTER This high-quality Hoya 58mm Linear Polarizing filter is in MINT (unmarked) optical condition, supplied with keeper and box. Linear polarising filters (i.e not circular C-PL) are for use with manual focus lenses only. Light rays which are reflected become polarized. Polarising filters are used to select which light rays enter your camera lens. They can remove unwanted reflections from non-metallic surfaces such as water or glass and also saturate colours providing better contrast. The effect can be seen through the viewfinder and changed by rotating the filter. The filter factor varies according to how the filter is rotated and its orientation to the sun. Filter factor is between 2.3 and 2.8 (approx. +1.3 stops). Will fit any Canon, Nikon, Pentax, Olympus, Minolta/Sony etc. lens with a 49mm thread. I endeavour to describe all items accurately. The image(s) shown above is of the actual item for sale and can genuinely be used as confirmation of the item's cosmetic condition. If you have any questions then please feel free to email me and I will answer as soon as possible. In the unlikely event that a buyer believes an item has not been described accurately, then please contact me within 7 days of the item arriving for return and refund (buyer to pay own return postage costs). Please only bid if you wish to buy! Many thanks for taking the time to look at my item.