Combining an image for depth of field
By Rod Barbee

 

 

With this image I combined in-field techniques with some Photoshop techniques. 

This scene of Upper Horsetail Falls in Oregonís Columbia River Gorge, photographed with a 12-24mm lens at 16mm mounted on a Nikon D300, posed some dilemmas. I wanted a long shutter speed to blur the waterfall and stream, yet I needed a fast shutter speed to stop the motion of the wind-blown foreground. To solve this, I took three shots focused at different points in the scene and then combined them in Photoshop.

It's extremely important that the camera position does not change between exposures. So be sure you figure out the exposures ahead of time and then lock the camera securely  on the tripod head.
 

Upper Horsetail Falls, Columbia River Gorge, OR

The first parts were easy. I took two shots at ISO 200 (for highest quality) focusing first on the background and then on the trees in the middle. These shots were at a f/16 and at about 1 second.
(Actually, I could have probably gotten away with one shot for both the middle and background)
 

 

 

 

 

 



focused on the cliff

 

 

 

 

 

 

 

 

 

 

 

 

 


focused on the trees

 

 

The foreground needed to be shot at a faster shutter speed, around 1/60 second, to stop the motion blur. This meant a relatively wide aperture. At ISO 200 the shutter speed was still too slow. ISO 640 allowed me to shoot 1/50 second at f/5. This was enough to stop the wind motion of the foreground.

As with nearly all waterfall/stream/forest pictures, a polarizer really helps with cutting the glare from rocks or leaves, and this situation was no different. With a regular polarizer, I would have had to use an ISO of 1000 to achieve the same shutter speed and aperture combination for the foreground image. But with my Singh-Ray LB Warming Polarizer, which is 2/3 stop faster than a regular polarizer, I was able to use ISO 640. On the D300 thereís not much noise at ISO 640, definitely less than there would be at ISO 1000. Using the LB Warming Polarizer I was able to shoot at an ISO that gave me the highest possible image quality given the situation.
 

After getting the images into the computer it was just a matter of layering one on top of the other and masking out the un-needed parts of each. (for more on layering the separate images, see my exposure blending tutorial)
Since focus is being changed with each exposure, this means that the composition is also slightly changed and each layer will be slightly "off" in alignment. You'll need to use the "Auto Align Layers" command (Edit>Auto Align Layers) before you start masking.
I also used Imagenomicís Noiseware for some noise reduction on the foreground layer. To finish up I cloned out the person under the waterfall and then used the "Stamp Visible" command (Control-Alt-Shift-E) to create a layer that is a flattened version of all the visible layers. I used this layer as a final tune up to adjust colors and bring out some details in the shadows using the "Shadows and Highlights" command.

Combining these shots was made easier with the guidance of Tony Kuyperís Digital Scheimpflug tutorial, which involves aligning layers and using masks. Tony Kuyper is a master at creating masks and using them to make powerful and pinpoint adjustments to his images. Heís created a great series of tutorials, most of them free, that will open up a whole new world of image editing for you.  

Tonyís website: www.goodlight.us