The Eye A Little Information

[smoke665]

As photographers we’re concerned with how we present the eye. An old saying I learned a long time ago “If you get the eyes right everything else falls in place”. Within the eye the iris is what we’re most interested in. Here’s a little background on the eye.

The word Iris (the colored portion of the eye) is derived from the Greek word for “rainbow”, also it’s the goddess plus messenger of the gods in the Iliad, because of the many colors within.

The Iris consists of two layers: the front pigmented Fibrovascular layer known as the Stroma and behind the Stroma, pigmented epithelial cells. The Stroma is a delicate interlacement of fibers. Some circle the circumference of the iris and the majority radiate toward the pupil. Blood vessels and nerves intersperse this mesh. In dark eyes, the Stroma contains varying amounts of (non-translucent) pigment granules. The eyes of albinos lack any pigment. Most would be surprised to note that Blue Eyes lack pigment also. Why we see the Blue is due to the Tyndall Effect – The Stroma is a translucent colloidal which scatters the light and much like a prism reflects the blue back.

The Stroma connects to a sphincter muscle which contracts the pupil (the center) in a circular motion much like the aperture on a lens, and a set of dilator muscles which pull the iris radially to enlarge the pupil, pulling it in folds. The back surface is covered by a heavily pigmented epithelial layer that is two cells thick, but the front surface has no epithelium. The anterior surface projects as the muscles dilate.

As a portrait photographer it’s important to remember that the eye produces no illumination and resides in a recessed protected position, but with external illumination, it will reflect the wonderful colors within. The photographer’s job is to provide sufficient illumination and of properly placed light for maximum reflection. In most cases the ideal location will be in the upper right quadrant.

 

[DanOstergren34 4]

In certain genres of portraits, like headshots, I completely agree that it is the photographer's job to provide sufficient illumination and of properly placed light for maximum reflection, but some portraits don’t benefit from bright, obvious eye illumination. I've seen many portraits where there is no or very little light in the eyes, but it was still very beautiful and even enhances the portrait. I think I would argue that the photographer’s responsibility isn’t to always chase a specific technical outcome. For me, the photographer’s job is to light the subject in a way that best serves the intent, whether that means strong catchlights or a more understated approach. But for traditional portraits and headshots, completely agree.

 

[smoke665]

@DanOstergren Perhaps there's a difference in the "amount" of light reflected, which in some cases could add drama to the scene. Maybe my comment should have been "provide sufficient illumination for the intended shot". However, the bottom line is without light there is no sight. The eye is non-luminous, it produces no light of it's own, without external lighting to reflect, nothing would show. Even the creatures with so-called "luminous eyes", like cats, dogs, alligators, etc., depend on light to reflect off their specialized reflective layer.

 

[Dale H. Cook122 16]

Maybe my comment should have been "provide sufficient illumination for the intended shot".

That is relatively easy to do (though sometimes requiring test shots) with a flash which provides manual adjustment of flash duration. I own three custom-modified Vivitar 283 flashes. One of those modifications involves replacing the plug-in photocell module with a miniature rotary switch That replaces the automatic adjustment of flash duration with full manual adjustment.

 

[smoke665]

@Dale H. Cook i had a 283 years ago, it was a popular model, just be aware that the earlier models had a sync voltage significantly higher than most modern cameras can handle. The 283 altered output by changing the flash duration. That said the light power is way under powered compared to studio lights.

External illumination doesn't have to be flash, it could be something as simple as a window, a reflector, or even a little LED light.

 

[Dale H. Cook122 16]

@Dale H. Cook i had a 283 years ago, it was a popular model, just be aware that the earlier models had a sync voltage significantly higher than most modern cameras can handle.

Thank you for the warning, but I have spent nearly 50 years as a high-level broadcast engineer, which requires major electronics knowledge and experience, so you are preaching to the choir. The 283s which I own (the fourth has not yet been modified) had original shoe voltages which I measured between 280 and 300 volts. Another part of my modifications is to reduce the shoe voltage to 5 volts using an opto-isolated thyristor driving a power thyristor capable of handling well over 300 VDC.

I do not often use speedlights for indoor work as I own two LED softboxes (part of my tabletop studio). There are times, though, when I need well-controlled three-point lighting indoors and use the Vivitars. Manual duration control is a big help in three-point lighting. Of course, I own flash snoods, diffusers, and other accessories.

 

[smoke665]

Thank you for the warning, but I have spent nearly 50 years as a high-level broadcast engineer, which requires major electronics knowledge and experience, so you are preaching to the choir. The 283s which I own (the fourth has not yet been modified) had original shoe voltages which I measured between 280 and 300 volts. Another part of my modifications is to reduce the shoe voltage to 5 volts using an opto-isolated thyristor driving a power thyristor capable of handling well over 300 VDC.

I do not often use speedlights for indoor work as I own two LED softboxes (part of my tabletop studio). There are times, though, when I need well-controlled three-point lighting indoors and use the Vivitars. Manual duration control is a big help in three-point lighting. Of course, I own flash snoods, diffusers, and other accessories.

I shoot Pentax, which is a PITA with their proprietary P-TTL. I have a AF-360FGZ for light outside work so I can do HSS & other options, and a battery power supply for up to (3)800ws studio strobes. In studio an assortment of (10) strobes ranging from 300ws to 1600ws all csn be controlled wireless from a hot shoe controller and various modifiers. Probably need to downsize some

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