Wednesday, April 28, 2010

Great Blue Skies Without A Polarizer

What the easy way to get highly saturated blue skies? Add a polarizer to the lens and fire away. What happens if your polarizing filter is back in the car/bag/hotel/case sitting at home? Today’s image didn’t have an extra filter on the lens, for whatever reason. I have to admit, the sky was pretty blue to start with on the day we were there, but not as blue as it appears in the shot. If you’re shooting in RAW, it’s not a problem. Just pick whatever White Balance you like. White Balance, like several other parameters, isn’t set in the camera when shooting RAW. The RAW image is just that, raw. It has no sharpening, color correction, white balance applied before being committed to memory. All adjustments are left up to the photographer (or finisher) once the shot is brought into your image editing application. That’s all well and good, for RAW shooters, but what happens if you’re shooting images as a JPG Fine? That’s the crux of the issue with today’s image. It was shot before I switched over to shooting RAW about 95% of the time. (An example of where I’d still shoot JPG happened over the weekend. I was asked to serve as photographer for the local March of Dimes Walk. It was strictly shoot and deliver, so, rather than needing to work and convert each image it was just easier t shoot JPGs and hand in the gratis assignment.) But, back to today’s image. The camera was on a tripod and I had a handful of Cokin filters to hold in front of the lens and, for a second set of experiments, cycled through the White Balance options on the camera. Since the camera was recording JPGs, each image showed the results of the filters and WB settings. To find out what set of conditions resulted in today’s image, hit the “read more”.

Most of the Cokin filters I had with me were either warming or graduated neutral density filters, so they didn’t lend themselves to heightening the saturation of the sky. They tended to give a later (or much earlier) in the day look to the scene. Switching the White Balance to either Cloudy or Shade gave similar, but not as intense, results. Going for either Tungsten or Florescent White Balance increased the blue in the sky and set up an entirely different set of White Balance issues. The whites became very cold and the reds flattened out. The best compromise wound up being Tungsten.

Once the overall tone was chosen normal color correction was employed. A Threshold Adjustment Layer was applied and the Black and White points found by moving the slider left and right. At each extreme the Color Sampler Tool (I) marked the points. A new Layer was put under the Threshold Adjustment Layer (CTRL & New Layer Icon in the Layers Panel), filled with 50% grey (Shift F5) and the Blend Mode changed to Difference. Going back to the Threshold Adjustment Layer and moving the slider to the far left identified the Middle Grey point. Adding a Curves (or Levels) Adjustment Layer provides “eye droppers” for Black, White and 50% Grey. Use each eye dropper on the matching point and color correction is done. The White on the lighthouse is white, the Blacks in the shadows of the rocks are black and the tone is brought into balance with the 50% grey eye dropper.

After any color cast has been removed (technique above), the individual colors can be brought to their best saturation using a Hue/Saturation Adjustment Layer for each color (Red, Yellow, Green, Cyan, Blue, and Magenta). Where almost all Adjustment Layer Masks were used on Monday’s image, almost all of today’s Adjustment Layer Masks were untouched. Some days the masks come into play extensively and some days not at all.

Just one side note. There were a half dozen tourists in the image creating distractions. I tried using the Content Aware Fill found in Adobe Photoshop CS5. It was basically a no go in this image. When it works, it’s amazing. When it doesn’t, you just have to g back to the older techniques.