Friday, June 02, 2017

Portraiture ~ Lighting Logic

Continuing my series on portraiture and the logic behind the set of instructions I'm sharing, we will now turn our attention to lighting.  For each detail I will try to provide a short explanation of it's importance.

Ninja ~ out of the Age of Steam

Camera Setup - 
  • Set the Exposure by using 
    • Manual Mode (typically "M" on most cameras)
    • 1/125th of a second for the shutter speed
    • f/5.6 or f/8 for the aperture
    • 100 for the ISO (or whichever is the lowest sensor sensitivity your camera offers)
    • Daylight for the White Balance
Manual Mode is selected because we need to bypass the in-camera metering system.  In fact, we want the flash to provide enough power that it itself determines the exposure.  Said another way, we should have enough light from the flash to make the impact of ambient light on our scene irrelevant.

1/125th of a second shutter speed is selected because many imaging devices come with a shutter curtain (physical or electronic) and the flash sync speed is typically 1/160th of a second.  Some systems will do better than this, but many flash/camera setups require additional setup and management to achieve the higher sync speeds.  In my experience, there is nothing to be gained.

I recommend setting the lens aperture to f/5.6 or f/8 as these apertures will accomplish two things.  First, when you subjects eyes are in focus, the depth of field at these apertures will get the nose to the back edge of the head in focus.  With this technique we are not trying to achieve the currently trendy limited depth of field kind of scene.  We want the full Rembrandt/Titian/Rubens/Lebrun painters portraiture details.

Secondly, using f/5.6 or f/8 will ensure that even if you are using the cheap kit lens that comes with many cameras, you will have eliminated the worst of the chromatic aberrations and gone beyond the apertures where spherical aberrations might be influential.  In short, these apertures will be the sharpest apertures your lens can operate at.  If things are too sharp for your artistic sensibilities, you can always soften the scene during image processing later.

I recommend you set the lowest ISO your camera is capable of because that is typically where your image will experience the least sensor noise and the greatest highlight and shadow details.  Keep in mind that as the ISO increases the dynamic range of your imaging system narrows and you will lose highlight and shadow details.

And lastly, I strongly suggest you set your white balance to Daylight.  Many imaging systems come with a Flash white balance option, but there's a problem when using an off-camera flash.  In my many experiences in using a broad variety of systems, skin tones are rendered too red when setting the White Balance to Flash.  Yet when White Balance is set to Daylight, skin tones are correctly rendered with every system I've ever tried.  Strange, perhaps, but true.

Set the Exposure -

By using the in-camera histogram to help set the flash intensity, you can ensure there is enough detail in the highlights and shadows.  We don't want either end "clipped" because that means we would have no information to work with during image processing later.

In the end and when you're all done processing an image you might want one end or the other of the exposure range "clipped", but it's best to begin with a file filled with detail because you might just as easily change your mind and want to use the information in those areas after the shoot.  The goal in setting the exposure correctly is flexibility.  Flexibility allows you a broader range of image processing choices.

Lighting Setup #1 -

This lighting setup is mimics Japanese woodcut "lighting."  It's known as Notan light.  William Mortensen and Robert Balcomb used this kind of light for many of their portraits.  The details of the subject are revealed and nothing is hidden.  It perfectly describes the subject.  I like about this kind of light because viewers don't know where the light is "coming from."

It is very good for portraiture where the subject is not in motion (real nor implied).  I like using this kind of light as it is soft, subtle, and lends the subject an air of substance, reality and truth.  
    Lighting Setup #2 -

    This lighting setup is what we commonly see in magazines and fashion work.  We know this kind of light as "chiaroscuro", or cross-lighting.  It's the classic light of certain periods of Italian painting.

    Cross-lighting for portraiture is expected.  It can reveal the shape and some of the depth of a subject.  Many photographers think of this as "Rembrandt light", or light that appears to spill onto one side of the subject as if through a window.  This setup is the one that will give you that "triangle" of light on the cheek on the off-side of your subject.

    Lighting setup choice -

    I've been giving this, perhaps, far too much thought and here is what I've come to.

    I've found it very interesting to see which kind of light has been used in which situation by looking at the works of the Old Masters.

    As an exercise to help us decide which kind of light to use, let's take a look at a few pieces of art.  Closely observe the following paintings and try to determine where the light is coming from and which light setup you would use to recreate that effect.  Ready?  Here we go -

    • Leonardo da Vinci - Mona Lisa (aka: la Joconde)
    • Titian - any of his portraits
    • Rubens - any of his portraits
    • Vigee Lebrun - any of her portraits
    • Auguste Renoir - any of his portraits
    Do you see a pattern here?  Which light do you think was used for all of this fabulous, timeless, portraiture?

    What about these artists?  Which kind of light did they use?  What was their subject?  How do these make you feel?
    • Gerard van Honthorst - almost anything he did (with a few exceptions)
    • Rembrandt's Nightwatch
    • Caravaggio - Supper at Emmaus,  Calling of Saint Matthew, Incredulity of Saint Thomas, etc.
    • Trophome Bigot - Allegory of Vanity
    • Gerard van Honthorst - Supper With The Minstrel And His Lute
    While the history of art and painting might not be quite as simple as I make it out to be (though it really does look like it could very well be), it comes down to considering just these two approaches.  You needn't rely on me to suggest how things are.  Walk the galleries of any museum in the western world and test this for yourself.  Here is how I see the effect of lighting for use in photography.

    Lighting Setup #1 (Japanese woodcut/Notan) is a calm, pleasant, elegant light.

    Lighting Setup #2 (Chiaroscuro) is a dynamic, active, dramatic light.

    In the next post on the logic behind my portraiture instructions I would like to talk about the art of portraiture.

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