I carry polarizers for all my lenses, even when shooting with my IR body. The effect is difficult (if not impossible) to match in post-processing.

I might use a clear filter over the lens if I were shooting in a situation where flinging mud or other soft debris may get on the lens element.

In addition to those above I use IR filters R72 and X-nite XDP.

For IR with the Kodak I still have frozen or Maco/Rollei, I like the #29 deep red. If shot in a Nikon with a Nikkor lens with a filter wheel, I have no choice but to use their #25 red.

I have several lens and would need filters of several different sizes so I make any necessary improvements in the computer.

The new UV filters for digital camera lenses are great + protects the expensive lens.

You cannot duplicate the effects of a polarizing filter in software, I do not use a filter for "protection".

All my lenses have filters for protection, just common sense.

I use a polarizing filter frequently, ND rarely.

Why put another piece of glass over an expensive lens. Can fix almost any defect on photoshop.

It's difficult to get good effects in software when a polarizer is really needed, and impossible to shoot cotton-y waterfalls without ND. Shoot sunsets without a ND grad at your own peril; it's kind of a must. Also I have a nice collection of starburst filters for a sparkle effect. Those aren't "normal" situations though; I still usually keep a UV/haze filter on for daily protection. All my filters are screw-in, FWIW. (Nikon D700/D300, lots of Nikon glass.)

Not only do I use polarizing, ND & Grads, but I also use many other special efx filters, such as the star and prism filters. I also have a D100 conversion for IR and I use color filters along with the ones above for amazing results. Yes, you can compensate by using programs from Nik, Tiffen, and Adobe, but getting it right and achieving your vision in camera is much more fulfilling than layering a simulation of the effect you are trying to attain. There are shots where it is necessary to do just that, but creating your image as you see it in camera will give you a greater sense of wonder and inspiration to try more wonderful feats.

I shoot digital and both color and black and white film so I use all the filters I've always used; UV, polorizer, orange, red and ND. Photography is photography, whether film or digital.

I like to use a circular polarizing filter occasionally.

I use uv/ir filters on Leica M lenses as required, and UV filters on Nikon lenses for protection. Sometimes I use a polarizer when needed.

For protection also! But software rocks when it comes to total choice for a final look.

Polarizing and ND -- yes. Grads -- never. Star filters -- seldom. For the most part, one cannot do in software what a polarizer can do. If I want a long exposure for blur or some other reason, NDs are necessary. While camera manufacturers are raising useful ISO levels, they're dropping the lower ones. I'd like to see really low ISOs so I wouldn't have to go to NDs all the time.

As I shoot film I use them to modify the scene as well as protection. The may include sky, warming, polarizing etc.

I do use a UV filter on all lenses as standard and as protection, along with the polarizer, ND, and Grads.

Absolutely. My photos are enhanced with the use of filters. My lens is protected too.

I prefer to interact with the subject and camera as much as possible. The more you can do with image capture, the less you have to do in the darkroom or on the computer.

I still like to get the picture correct in the camera before it goes to post-processing.

Being committed to film I use a variety of filters. Polarisors are used to reduce reflection and increase contrast in blue skies with white clouds. I use ND for slow speeds with fast moving water and grad. ND's for controlling the bright skies in my landscape shots. Even when shooting digital, I still use such filters. I am a firm believer in getting it right "in camera", to the greatest extent possible

I occasionally will use a polarizing filter when photographing seascapes with lots of clouds.

I used to also use a UV filter for lens protection but gradually have given up on that practice.

Sometimes the organization I shoot for uses the photos immediately, with no time for editing. I use filters to get the best shot right out of the camera.

Wouldn't be without them for landscape shooting!

I love using polarizing filters. I feel more connected to the photos that way.

I still think it's important to get the best possible capture in the field.

I shoot more film with my Nikon equipment, so I am use to creating an effect in pre-production instead of post-preduction. I am also able to use my lenses on both my film and digital cameras. Of course I like the fact that if something hits your lens the front element isn't ruined, only the filter.