Originally Posted by
CPRich
Circular Polarizer - you can't put back in Photoshop what's not captured. If you capture a bunch of white glare reflecting off water, you can't PS back-in the image behind the glare.
Graduated ND filter - external Cokin mount so split can be placed where needed. Again, blown highlights can only be brought to lighter shades of gray in PS. Shots with different exposures can be merged in PS, but only with fully static scenes.
ND filters - 3 stop - to get slow exposure speeds in bright light - waterfalls, etc.
<aol>Me too!</aol>
My wife got me a set from Cokin that had 3 GNDs - soft 1-stop, 2-stop, and 3-stop. I pretty much only use the 3-stop. For kicks and grins, I also got a graduated blue one, but I haven't been able to get anything useful out of it yet.
Some pixel-peepers complain that the (cheaper) Cokin filters aren't neutral enough and that you need to spend >$100 and get the Singh-Ray filters. I don't buy it. Here's a shot I did with the 3-stop GND (which should look familiar to you, CPRich):
(Nikon D70, 18-200VR @18mm, f/8, 3 stop GND positioned slightly crooked so that the sky over the valley was filtered)
(this was my web proof, so I didn't do anything about the corner vignette)
Normally, I keep a UV filter on my 18-200 since the front element is easy to get to. I don't bother on my 50/1.8 because the lens is inexpensive and the front element is hard to get to - I'd have to drop it on a pointy rock)