Wednesday, April 20, 2011

We Interrupt Reverse Engineering for a Worthwhile Diversion

I recently received an email from Sean McHugh, author of cambridgeincolour.com, notifying me of new portrait-lighting sections on his site. These new sections feature nifty 3D renderings, and excellent explanations. If you've never visited this site and are, like me, looking for clear explanations of photographic technology, this is something you have to check out. Below I've listed links to the aforementioned sections and to the site home page. Hope you enjoy it.

Portrait Lighting

Fill Lighting

Home Page

I'll post another section on reverse engineering this coming week.

Monday, April 11, 2011

Reverse Engineering: Examining the Shadows

I look at shadows, reflections, and lighting contrast when I want to reverse engineer another photographer's lighting. By examining shadows, one can learn a lot about the position, size, and character of the light source. Today I will use a few full-body shots from a recent clothing-line shoot to examine how shadows vary with light source. All of the following images were created in a relatively small room measuring 13' by 18' with an 8' ceiling. Ideally, you would want to shoot these types of images in a much larger space.



The image above was created using a studio flash with the first version of the Paul C. Buff 64" Silver PLM, a large 16 panel silver umbrella that is shaped as a proper paraboloid. The PLM creates a soft but snappy light that I like. It takes well to feathering and was feathered in this example with the light axis forward of our model. A second studio flash was bounced off the white wall behind the camera to produce fill lighting about 1.7 f-stops less intense than that from the PLM. Notice that the shadows thrown to the model's right (our left) are quite soft, but definitely more distinct than those from a softbox of similar surface area. If you click on the photo to get a larger view, you can examine the smaller shadows on the face. Again, these are definitely more distinct than from a large softbox, but much smoother than you'd expect from smaller parabolic or beauty-dish reflectors.



The green-dress-composite image above uses a lighting similar to the prior example, but the PLM was replaced by a studio flash using a standard reflector with a coarse grid and barn doors. The fill light output was increased so that it was only 1.25 f-stops less bright than the grid light. The barn doors where used to block light from falling on the floor or background. This kind of light emphasizes texture and creates very distinct, hard shadows. I generally favor larger sources when doing full-body shots, as I usually find the hard shadows that fall on the floor or surrounding background to be unpleasantly distinct. Click on the image and examine the shadows around the face, and especially those created by the dangling earrings or eyelashes. You can expect small sources, including strobes with their standard reflectors and bare-bulb configurations, to give similarly hard shadows.





The blue-dress shot above was created with a large softbox (100cm X 130cm) oriented horizontally and positioned much like the PLM. In place of a fill light, a large white reflector was placed to our left and somewhat in front of the model. Notice the soft, indistinct and fairly uniform nature of the shadows on the floor beside the model. A bigger softbox would give less distinct shadows and a smaller one correspondingly more defined ones. Satin umbrellas of similar area will give a similar shadow quality, although there will be a slight difference. The umbrella shadows are usually slightly less uniform in the body of the shadow, and the shadow edges slightly more graded.




The final example was lighted with a large beauty dish (24") positioned well above the camera and with a 42" X 42" silver reflector below. This particular beauty dish has a very wide angle of coverage, making it a good choice for pairing with a reflector. The shadows in this example are thrown directly behind the model and are moderately distinct. A smaller dish will provide a tighter shadow with a more distinct edge and a larger source, such as 38" satin umbrella, something a bit softer.

Keep in mind that these examples are just rough points of reference. If you work with different equipment, with different light-to-subject distances, or in a larger space, you will likely get somewhat different results. I'd like to thank Frank for allowing me to use his clothing shots as examples, Lenny for his outstanding makeup, William for his hair wizardry, and Tiffany, our model, for enduring the cold and still delivering a boatload of great poses.

In the next post we'll look at eyes and see how they can be the single-most-important tool for gaining insight into the lighting.

Sunday, April 10, 2011

Reverse Engineering Lighting

OK, I'm back at it. I don't know about you, but when an image catches my eye, I almost always analyze it. I look for clues about lighting, lens settings, post-processing adjustments, etc. In the next few posts I'll describe what I look at to deconstruct lighting. In tomorrow's post we'll use a series of full-body images to illustrate how different lighting sources render shadows.