Here is a little blip about using a neutral density filter for landscape photos. You can almost get the same effect by shooting a RAW image on a tripod and making an HDR image.
For this image, I used a 4-stop hard-edged ND grad to hold back the sky. I also used a 5-stop ND filter to slow the exposure enough to get the water silky smooth. 6 seconds, f/16, ISO 100. EOS 5D Mark III with EF 16-35mm f/2.8L II.
As I’ve written before, the hardest part of landscape photography is retaining detail in a bright sky with a darker foreground. There are several ways to deal with this issue. The newest ways involve various post-processing techniques in Photoshop or Lightroom, or using High Dynamic Range photography to blend several exposures together, retaining both shadow and highlight detail from these exposures. There is nothing wrong with these techniques, and in fact there are times where these may be the best method for keeping detail in the sky. There are issues with both blending and HDR. HDR tends to have a very processed look to it when not done well, and blending takes time to do well. I am not one who likes to spend much time in Photoshop with my images. In addition, you still need to be sure that you somehow capture enough information in the sky that you are not simply darkening down white pixels.
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