Tuesday, May 25, 2010

Control Dynamic Range With ND Grad Filters

Control Dynamic Range With ND Grad Filters ( Pictured above , Cokin Neutral Density Graduated Filters plus Polarizing Filter a must have for any landscape Photographer)From left to right. Circular Polarizer, ND 8(4 stop) hard edge , ND 8(4 stop) soft edge, ND 4(2 stop) soft edge, ND 2(1 stop) soft edge.
This shot was taken at Spanish Banks , above without any filters and you can see all detail is lost in the sky. Below I tamed the contrast with a ND 8(4 stop) Hard edge Grad Filter plus Polarizer. F22 @ 3.5 sec . iso 100
One of the questions I get asked the most is how do you get such dramatic Sky's with out losing color and detail in the for ground ? The answer , Graduated Neutral Density Filters . The problem we face as Photographers is controlling the dynamic range of light from your brightest highlights to your darkest shadows in one exposure. Unfortunately our camera sensors will not record a drastic Raing of light as our eye sees. what happens is you see a great sunset seen and you take the shot only to review and see nothing as you remember it . Either your sky is bright and washed out or you are left with a nice sky but a black dark colorless for ground . If only there was a way to control this, and there is !

Graduated Neutral Density filter are filters which we hold in front of the lens , they are dark with a neutral grey color on the top half and clear on the bottom half. When I take a shot I can review and see were I have lost detail ( usually in the sky ) I can use the cameras light meter to calculate the difference in stops between the Highlights and shadowes . Once I have done this I will be left with a for ground full of color and detail , The sky will be washed out , now I place the filter in front of the lens using the darker side on top . You will be able to see the change immediately through the view finder. The sky will be brought back to life in all its glory and color!

These filters come in a range from very dark 4 stop to slightly dark 1 stop . The edge of the dark tint will be made with a soft edge ( more gradual change from dark to clear ) or a hard edge ( a very sharp change from dark to clear) . Both have advantages , a straight horizon line with out many obstructions would work well with a hard edge , on the other hand shooting a mountain seen would work great with the soft edge in order not to darken the mountains to much. Cokin and Sing Ray are two company's that specialize in these types of filters , they both make a wide range. Also note that a good circular polarizing filter is also a must to cut glare and saturate color . I also use a stable tripod and a remote release ( the remote release fires the shutter with out me touching the camera) to ensure tack sharp shots especially at slow shutter speeds.
I hope this is a tip that we can all use to help us achieve better Land Scape Photographs , Now just get out there and shoot !!

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