How to Use a Neutral Density Graduated Filter by 5minArts
Besides a tripod, a Graduated Neutral Density (ND) Filter is probably one of the most important accessory a landscape photographer can buy. Remember all those reviews you’ve read about blow-out skies? Well, a graduated (or variable) ND filter will quickly solve this problem.
A graduated ND filter help retain detail in both the sky and the land portion of your picture. If you measure the land portion, the sky typically gets blown-out, over-exposed, turns out white. If you measure for the sky, the latter turns out great but then the land portion is now underexposed.
Of course, you can do HDR photography: take 3 pictures, one of the sky, one of the shadows, and one average. Then, in software (or in-camera if available), merge these 3 exposures into one.
Or, by simply positioning your graduated ND filter so that the dark portion is at the top and the clear portion at the bottom, you can reduce the amount of light coming from the sky while not affecting the rest of the scene. Your photo is now exposed properly for both land and sky.
Graduated ND filters come at different strengths, typically 0.3, 0.6 and 0.9 ND. How do you know which one to use? Measure the sky by itself, then measure the ground. If you measure a 1-stop difference, use the 0.3 ND grad; a 2-stop difference, use the 0.6 ND grad; a 3-stop difference, use the 0.9 ND grad. Manually set your exposure to that of the ground.
Check out the Tiffen variable ND filters
source professional photographer
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