Because a camera has a limit to the range of brightness it can cope with (much less than that of the human eye), I often use an ND Grad filter (Graduated neutral density filter) to reduce the range of brightness in a scene to something more manageable for the camera.

To see what an ND Grad filter looks like, here's a reasonable article: Graduated neutral density filter

ND Grad filers are probably my favourite filters to use. They allow me to capture scenes with bright skies yet still retain brightness and detail in the foreground.

The next two images show the same scene, without any filters, exposed differently. One is exposed for detail in the foreground and the other for detail in the sky.

So you can see that neither image really works and it's certainly not how I saw it with my own eyes while standing there.

To help the camera see it how I see it, I need to tame the difference in brightness so I can get good exposure (and therefore colour and detail) in both foreground and background of the scene. That's where the ND Grad filter comes in.

This next image shows the result. I was using manual exposure and everything is exactly the same as the image above, except for the 3-stop ND Grad filter attached to the front of my lens.

That's much more like what I saw and wanted to capture on camera.

Here are some more shots from the same outing.