What type of filters should I get for high sunny conditions?

Question

I'm planning a trip in Sri Lanka and Maldives Islands next month. In such sunny conditions, I would like to buy filters for a Pentax K20-D, to be able to take pictures of the sea, the beach, etc. (but not underwater) in the best possible way.

What type of filters are the most suitable in this situation? Do you know specific model/brand/recommendation for Pentax DSLR?

Answer 1

If you have trouble with to much sun, a ND (Neutral Density) might be want you want. This gives you the option of having a higher aperture even when there is much sun.

A polarization filter might also be handy. This way you could get rid of the reflections from the ocean. Also you could get that postcard feeling with a more blue sky.

There are many people who put on a UV-filter for protection. But this is a widely debated issue. I will not go into detail about that, but here is an article on the subject. Bear in mind that a UV filter might introduce a lens flare, especially when there is much light.

You can stack several filters, like the ND and the polarization filter. However there might be problems with vignetting. This also depends upon the lens you are using.

Personally I use Hoya filters because I consider they to be of high quality. However I have no scientific evidence that they are better than other brands.

Answer 2

In addition to the great suggestions by @Johan Karlsson, you may also want to look into Graduated Neutral Density(GND) filters. There's a good video description here.

These can be handy for when the sun is higher in the sky; you put the darkest portion of the filter at the top and it will reduce the intensity of light coming from it. There's also a reverse graduated ND filter, sometimes known as a "sunset" filter; the darkest part is in the middle and gets lighter toward the edges. This allows shooting a sunset and filtering out the intense light from that while still allowing you to capture the foreground and upper sky (clouds, etc.) without being too dark.

As you can see from the video I linked to, GND filters are usually square or rectangular; they do not screw in like other filters. Instead, you screw in an adapter/holder and put the filter into the holder, which allows you to slide it up/down to get the desired positioning.