newbie filter questions

I recently purchased a Nikon D50 with a Sigma 28-105 DG f2.8-4 lens. I love the camera and have taken some impressive pics with it. I have considered getting some filters to add some special touches to my photos. Finding photographic examples with and without certain types of lenses, has been hard for me. I have found alot of technical info on filters that I am, honestly, not educated enough to understand how they would affect a photo. Here are some things I would like to change in my photos...

Take long exposure photos (5 seconds?) of waterfalls in the daytime (ND filter?)...
Eliminate the dominance of red and orange colors in some situations...
Have more blueish color in photos (Have seen some photos with a blue tint that look great)

My question is, do I buy filters to do what I want or do I buy a software program to make the corrections I want. I know that software would not do what an ND filter would but maybe I could make the other corrections. Is there a basic filter package that would be good (but not too expensive) to have? Just looking for advice on how to choose what I need. Thanks for any input you may have and please forgive my ignorance on this subject.

Nathan

The first filter and one of the few you probably need is a Circular Polarizer. It will cut down your exposure by at least 1-2 stops and give you the various glare reducing, color enhancing (bluer skies) effects they are known to produce. One filter that might, and I repeat might, be what you are looking for is a graduated neutral density filter. 'Grads' as they are sometimes called start light on one side and 'gradually' shift to darker or greater density on the other side of the filter. There are also graduated filters for color shifts from one side of the filter to the other as well. The dynamic range (difference in light and dark in a scene) is one of the harder things to capture and certainly is a digital difficulty.

You can spend quite a bit of time and money exploring filters and then probably decide that the software solution provides far more flexibility.

There are various software options now for digital to change toning (tints) and to filter colors either to reduce/shift the saturation or to generate black and white images. Filters are fun to experiment with but rarely are they necessary in the digital darkroom age. Whether you go with an Adobe product or Corel or JASC several different tools are available to make these kinds of modification. Check the reviews atReviews Page for Digital Photography Software.

For long exposure the other vital piece of gear is a good tripod.

You also might wish to look through the galleries at some of the images that are similar to what you want to acheive and look at the settings listed to see if that might guide you in terms of how it was done. 5 seconds is a long time in daylight.

Hope this is a little help and Best Wishes. Looking forward to seeing some photos!

The ND and polarizers are really the only useful ones for digital these days. Everything else has been made obsolete by the fact that digital files inherently store red, green and blue components of the image.

FIlters are a great way to take your photography to the next level. having said that there are a few issues relating to filters with digital cameras.
First if you are using a filter that alters the colour of an image you will need to manual white balance the camera before you take the photo and use a mode that imbeds the colour information into the file (basically anything except raw) you will also want to make sure that the saturation and colour tones are set to your liking before you put the filter on the camera as this will also alter the effect the filter gives. the exception to this are neutral density (ND) and polarising filters unless the polarising filters are the rarer polacolour kind. i think getting a brochure with examples from the likes of marumi, hoya, cokin, B&W or one of the many other fine filter manufacturers would be a good start. and then play. incidentally photoshop 7 and newer versions have electronically emulated the effects of most common photographic filters like the 81b (warming filter) oh and you may be able to replicate the effects of ND filters by playing with your iso settings on the camera but there are some situations where they are still very handy.

The only filter I regularly carry anymore is a circular polarizer. Since it's neutral and will lower the light level by 1-2 stops it can "sort of" work as an ND filter too, to some extent.

I prefer to do everything else with Photoshop, including b&w conversions from color originals. There is so much more control by doing it this way, and less stuff to carry.