Filters

Hi,

I am looking for opinions on Filters.

I have a D90 with 18-200VR Nikon lens and 50mm F1.8 Nikon and are primarily interested in landscapes (still looking to buy a wide angle lens).

Anyway I have a protective UV Lens on my Lenses, but have read that many landscape photographers use filters , my questions are....

1) Is there anything software cannot do that a filter can.

2) I see a very disparate price range of filters , is there a noticeable difference between a cheaper filter to a very expensive filter.

3) What are the essential filters for landscape photography.

1) Is there anything software cannot do that a filter can.

Yes, software can't make as much of an adjustment as a graduated neutral density filter will to the sky while leaving the middle and foreground untouched. Even if you shoot in RAW mode.
HDR software may seem attractive, but the movement of foliage will leave light haloes along the skyline which is hard to work around.

Software can't realistically do what you can with a full ND (ungraduated) filter where you slow the shutter speed to blur moving water in bright sunlight.

Software can't remove reflections like a polarising filter does, although a polariser works best at 90 degrees to the sunlight and with extreme wide angle the change in sky intensity shows up.

2) I see a very disparate price range of filters , is there a noticeable difference between a cheaper filter to a very expensive filter.
Oh yes.
Anything you put in front of your lens is going to affect the image quality.
So look for multi-coated filters to reduce reflections, look for neutral grey colour in the polariser - some appear to have a colour cast.

3) What are the essential filters for landscape photography.
Tricky, there is probably no right answer here.
If you're not photographing moving water or windblown grass, and don't want the blurring of slow shutter speeds in bright light then a neutral density (ND) filter is probably not essential.
Polarising filter if you're photographing water, and want to see past the reflections.
Graduated ND filter(s) and holder system if you have bright skies and relatively dark landscape.

But do you need filters at all, are they essential?
I'd argue that they are not essential, until you move to creative shutter speeds and extreme lighting contrasts.
I haven't got that adventurous, and I haven't felt the lack of filters for landscape yet.

Thank you Paul, your comments are apreciated.