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Saturday, January 22, 2011

Create a Vibrant Lighting Effect With Cross Polarization

Light has the ability to create many different types of dramatic effect, though there is none as vivid as cross polarization. It awakens the imagination with its vibrance of colors. Though this technique was popular 20+ years ago, it seems to have been lost in the digital shuffle. This tutorial will walk you through the process and equipment to experiment with cross polarization.

Final Image Preview


final

Introduction

As I was a commercial artist/photographer 20+ years ago (and I love great cross polarization) I will lay before you the “secrets” of this phenomenal lighting technique. I will also provide you with a source for the necessary linear polarizing film, since I know you want to start with the same advantages I have! The film is not expensive and it will provide you with (hopefully) hundreds of great shots.

Step 1: What You Need and What I Use

  • The first, and most obvious, item is a camera. I used the Nikon D200 but any camera you can use with the required circular polarizer will work just fine.
  • The second item is a lens. I used the AF-S VR Micro-NIKKOR 105mm f/2.8G IF-ED as I am a fixed focal length gal and this is one lens I love!
  • The third item is a tripod. I used my Manfrotto but any tripod will do.
  • The fourth item is the secondary element, key to creating this procedure – a circular polarizing filter to fit the chosen lens. I used a Hoya 62mm.
  • The fifth item is that all-important light source. I used a Gepe Slim Lite 5000 but even a window in daylight will do.
  • The sixth element is the main part of the cross polarization magic and the most difficult to obtain as you don’t know what you’re really getting when you order online. It is the linear polarizing film. I use item number PF006 found at polarization.com.
  • Last (but not least) is the subject. You can try as many pieces of plastic as you can find. For this tutorial I am using a $5.00 Christmas angel.
Shown below is my Gepe Slim Lite 5000 with film in place.

My Gepe Slim Lite 5000

Step 2: The Subjects

Cross Polarization is actually a scientific application that finds weaknesses in glass and plastic. My rule here is to grab the cheapest plastic you can find. One of my most popular pieces is a 20 cent party favor. You’re looking for cheap plastic. The photo shows some pieces I’ve picked up over the years. November and December are the best times to find great pieces for this project as so many Christmas ornaments are elaborate but really just cheap plastic. You may notice in this photo that my polarized light source was turned on to the left of these pieces. That is why some subtle colors are showing up. There was no circular polarizer on this lens.

preview

Step 3: Set Up the Shot

The photo of the setup shows that I placed the Linear Polarizing Film directly between my light source and my subject. For my angel, I have to place my light source in this vertical position but for most shots I set my tripod up as a copy stand and place my light source on the floor.
For the studio work I make sure there are no unpolarized light sources around. Of course, if you’re working in daylight, this will not be necessary. The key is to make sure that light contamination from other light sources (fluorescent, tungsten, sodium vapor, etc.) doesn’t creep into the shot. These contaminates can severely alter and lessen the colors captured as they add their own color.

set up

Step 4: How to Compose the Shot

Composition is always a serious issue in photography. My advice here is to ‘tighten’ your image by moving in as close as you can. This rule can even eradicate/eliminate light contamination. Check your saved shots regularly to ensure your composition is what you want.
When taking your light reading you must take into consideration whether your background is to be white or black. For a good black background, take your light reading from the lightest part of your subject (low key). If you’re going for a white background, take your light reading from the darkest part of your subject (high key). Be careful of the high key approach as it often causes loss of detail in the brighter parts of the image.

Composition

Step 5: Your Key to Light

The illustration shows light waves that are making their way to your film/sensor. When the polarization from the front element of your circular polarizer is parallel to the light waves, your background (light source) will be white. When the polarization from the front element of your circular polarizer is perpendicular to the light waves, your background (light source) will be black. Also, what was showing up as blue in the parallel position will come through as yellow in the perpendicular position. You are basically creating (and in control of) polar opposites.

Light Waves

Step 6: Camera Settings

I highly recommend a tripod for this type of work as you want to completely control the exposure. For the final preview shot, I had the aperture set at f/11 (I always use f/11 or smaller) with a shutter speed of 3 seconds and the ISO set at 100. I used the camera’s timer for the shot to avoid any camera shake but a remote would work as well.

Camera Settings

Step 7: Working With the Files

Begin by opening the RAW file with Adobe Camera Raw (ACR).

Open the RAW file
Note: If the RAW file is not available you can open the JPG in ACR through Adobe Bridge or just spend a little extra time in Photoshop.
You will see that there are some critical adjustments you can make here. I normally adjust the Blacks, Contrast, Vibrance, and Saturation. Once these are acceptable, I may tweak the Exposure. Click “Open Image.”

Adjust the RAW file

Step 8: Bringing it Into Photoshop

The first thing you want to do is look for any dust or other marks that may be left in the shot. I cleaned the glass and film prior to the shoot but dust has a way of sticking around. To clean this artifact, select the area and then fill with black (or white if you’ve shot high key).

Cleaning up
The next thing I did was to select the base cloth the angel was standing on so that I could remove it as well. I could have adjusted my Blacks in ACR to get rid of this but I would have had to make a larger adjustment to my exposure. Once the selection is made, fill with your background color (in this case, black).

Cleaning up
Even though you’ve opened a vibrant shot, many of the captured colors are still lost to the eye.

The Shot
Had this been done in the days of abundant film, this would have been recorded on Kodachrome 25. I would have done this with my trusty 4 x 5 camera and made six shots, each one increasing the exposure by a full stop as my initial reading would have been done with a hand held light meter and a rough two stops would have been added to that reading due to the use of the circular polarizer. Exposure is the key and printing the Kodachrome slide was my post-processing. So what we’ll do now is play with the Vibrance and Saturation.
Go to Image, Adjustments, Vibrance (Alt I > A > V). Play with the sliders until you’re happy with the amount of color you’ve brought out. The photo below is a bit exaggerated but I wanted to show all the colors lurking in the plastic.

More Adjusting

Step 9: Now for the Pièce de Résistance

As previously stated, you can shoot this as high key or low key. I prefer low key as the slight underexposure is far easier to work with than lost details. Now, I really like the color shifts in the high key images but that is fairly easy to accomplish in Photoshop. If your subject has areas that will be easily blown out by a bit of overexposure, all you need do is complete this tutorial for the low key image then invert (Ctrl I). The first pair of images below were shot as high key and low key. The second set was shot as low key then inverted.

Original Playing With Plastic
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Original Dark Angel and Light Angel

Conclusion

Dazzling effects are but a few steps away. One final trick to note is that I took my Linear Polarizing Film and taped it to a piece of 1/4 inch glass. This makes it easier to handle, but be sure to tape it all the way around so that no dust gets in. You must also make sure it is annealed glass as opposed to tempered (or safety) as tempered glass has faults (break points) that will show up.
Have fun experimenting with the effect, and feel free to share any examples or photos in the comments!

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