Photography Safety

About the author: Bill Rogers has over 30 years’ experience in environmental safety. Now retired, he was a Certified Safety Professional (CSP), and has written numerous journal articles and taught extensively on safety, loss prevention, and risk management topics.  In 1992, he wrote and published a successful book that included practical strategies for prevention of employee injuries. He also earned a Masters’ in Business Administration (MBA), and is credentialled as a Chartered Property Casualty Underwriter (CPCU) and an Associate in Risk Management (ARM). His understanding of photography, environmental safety, and electronics makes him uniquely qualified to discuss photography safety.

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Photography is a relatively safe occupation and hobby. Nevertheless, there are hazards that can cause injury to the photographer and others. These tutorials will discuss a few such hazards and how each can be reduced or eliminated.

Note: These tutorials are not a complete list of photography hazards and perils. New topics will be added from time to time. Please use common sense and do not rely on these tutorials to identify all risks and control measures.

Tutorial List:

  1. Extreme Hazard: Use of Household Connectors in Strobe Sync Wiring (scroll down)
  2. Basic Electrical Safety for Photographers

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Extreme Hazard: Use of Household Connectors in Strobe Sync Wiring

 Summary

The use of the Household (HH) connector for photographic flash and strobe synchronization is extremely hazardous. It can expose unsuspecting adults and/or children to severe electrical shock and/or electrical burns. Such injuries can be fatal.

The optimal control measure is to immediately discontinue the use of this connector for this purpose. This tutorial offers advice on alternate control measures when the optimal control measure is impractical.

Alternate control measures are necessary because there is an installed base of strobe equipment using HH connectors.

My primary objective is to motivate both photographers and manufacturers to quit fabricating and manufacturing new cords and strobes using HH connectors.

Background

Photographers use various methods to synchronize electronic flash or strobe units with a camera shutter — optical slaves, radio slaves, and low-voltage wiring. Even the so-called wireless methods often use short (pigtail) electrical cords with connectors on each end.

The 1/8-inch coaxial PC (Proctor-Compur) connector was designed for flash and strobe synchronization. It is quite small in every dimension, something that was important when shutters were included within the lens assembly. Today, most professional cameras have an integral PC terminal that accepts a male PC plug. Even though PC connectors were designed for this purpose, they are notoriously failure-prone because of their small size, simplistic design, and a lack of industry standardization.

Because of this, strobe and flash equipment manufacturers often use other, more reliable, connectors for strobe synchronization. Some are proprietary – i.e., they only work with one manufacturer’s equipment – while others are commonly available:

  • 1/4″ (6.3 mm) phone plug and jack *
  • 1/8″ (3.5 mm) miniphone plug and jack *
  • 3/32″ (2.5 mm) subminiphone plug and jack * 
  • Hot shoe
  • Household (HH) connector, more correctly called a NEMA connector, and also known as an Edison plug.

                   * There are two types of phone plugs and jacks — mono (tip and sleeve) and stereo (tip, ring, and sleeve).

The HH connector is identical to the non-polarized 120-volt NEMA connector used for electrical power wiring in the United States. NEMA connectors in various forms are found on refrigerators, toasters, microwave ovens, clocks, lamps, computers, televisions, vacuum cleaners, and thousands of similar devices in the USA.

The Hazard

HH connectors are designed for high-voltage, high-current applications. In contrast, strobe sync circuits are low-voltage, low-current applications. (Note: the terms “low voltage” and “high voltage” are relative, of course. In this tutorial, “low voltage” refers to the voltages used in modern strobe sync circuits; that is, under ten volts, non-lethal, and in most cases unable to be felt by an adult through intact skin. “High voltage” refers to the potentially-deadly 120 volts found in wall outlets in the USA.)

All the connectors described above, with the important exception of the HH connector, are low-voltage, low-current connectors.

Why is this important? Common sense, as well as standards set by Underwriters Laboratories and the National Electrical Code, mandate that low-voltage connectors are used for low-voltage applications, high-voltage connectors are used for high-voltage applications, and the two are never mixed. Also, connectors that are energized with high voltage are exclusively female connectors.

The use of HH connectors for strobe sync breaks both of these rules. In fact, this is the only routine use of HH connectors in a low-voltage circuit. Think about that. In the millions of electrical and electronic applications in the USA and most of the world, photographic strobe and flash sync cords are the only ones that use a HH connector in a low-voltage circuit.

In the USA, electrical power is 120 volt a.c. (alternating current). It appears in dozens of receptacles installed in our homes. It is so common that many people do not realize that contact can be fatal. Alternating current can paralyze muscles, making it difficult or impossible for the victim to release contact. In addition, the a.c. sine wave can superimpose itself over the heart’s normal electrical signal, resulting in ventricular fibrillation. Children are more vulnerable than adults because their skin has less resistance and their nervous systems are not mature.

What photographic equipment uses HH connectors?  

HH female connectors are becoming less common as strobe manufacturers discontinue their use. They are still being offered on a few studio strobes, however. For example, as of this writing, Novatron equipment uses an ordinary two-prong female receptacle for synchronization. Novatron’s website includes this laughably inadequate safety warning: “Please be real careful with your sync cord. Don’t let anyone plug it into a wall outlet. The results could be disastrous.”

Other manufacturers such as Dyna-Lite have attempted to mitigate the problem by adding a third blade or pin between the two blades of the HH connector. This additional blade or pin prevents the male connector from being inserted into a wall outlet. However, the female receptacle on the strobe will accept either a normal two-prong HH connector or a three-prong substitute. From a safety standpoint, this solution is unacceptable because it still allows an ordinary HH male plug to be used for strobe sync.

One acceptable solution is to use 1/4″ or 1/8″ phone connectors for sync.  Profoto and Norman use 1/4″ connectors; there are many others.

Why do photographers continue to use HH connectors?

Photographers who use strobe and flash equipment equipped with ordinary HH female connectors have no choice but to use a HH male plug. This includes currently-manufactured equipment by companies like Novatron, mentioned above, as well as older equipment. Safety suggestions for photographers in this situation are discussed below.

Because HH connectors and lamp cord are readily available at hardware stores, some photographers use them to build “Do-It-Yourself” (DIY) sync cords. I recently became concerned because www.strobist.com, a popular website for photo strobe and flash enthusiasts, provides detailed instructions for assembling a DIY sync extension cord using HH connectors. This sync cord could be built using either 1/4″ or 1/8″ phone plugs, in which case it would be safe.  

When challenged, photographers defend the use of HH connectors with arguments like these –

  • “I’ve never heard of anyone being injured in this fashion.” In the USA, about 500 people are killed by electricity each year. This is more than one per day. These incidents are not reported in newspapers unless they are local news. What makes people think they would hear about it? If you’re 40 years old and have been reading the news for 20 years, 10,000 Americans were electrocuted in that 20-year period. How many of them have you heard about?
  • “Only in America are people unwilling to accept responsibility for their own personal safety.” Ironically, I am in fact asking people to take responsibility for their own personal safety and the safety of others by implementing a common-sense precaution. What these people really mean is this: “As an American, I have the freedom to take stupid risks, and if I kill myself, it’s nobody’s fault but my own.” I wholeheartedly agree, as long as your risk-taking does not endanger innocent bystanders, especially children. For instance, if you ride a motorcycle without wearing a helmet, you are only endangering yourself. But if you drink a six-pack of Olde Frothingslosh and then ride your crotch rocket 60 mph in a school zone, you are endangering others as well as yourself.
  • “Children can stick paperclips and car keys into electrical outlets. Should we also get rid of these?” Household plugs are designed to be plugged into electrical outlets. Paperclips and car keys are not.
  • “We can’t live in fear all the time.” True, and by taking a common-sense precaution to reduce risk, you’ll have one less thing to worry about.
  • “You’d have to be stupid to plug a sync cord into an electrical outlet.” Household plugs are designed to be plugged into electrical outlets. They look just like plugs from table lamps and alarm clocks.
  • “Household connectors are cheap and plentiful.” Yes, they are, and so are 1/4″ phone plugs and jacks. In fact, the cost of phone connectors and HH connectors is almost identical.
  • “The risk is extremely small from a statistical standpoint.” I agree, but this is just one of three criteria that must be applied to risk evaluation - 1) the likelihood of occurrence, 2) the potential severity of occurrence, and 3) the cost of prevention. In this situation, the likelihood of occurrence is indeed small, but the potential severity is extremely high (death), and the cost of prevention is quite low.
  • “I keep careful watch over my photo equipment and would never allow this to happen.” I’m sure than many photographers take this precaution. Consider, however, the possibility that a sync cord may easily outlive the photographer; what could happen then? Modern plastic insulation can last 40 or 50 years, and I, for one, know I won’t live that much longer.

Prevention

Immediately quit using household (HH) connectors for flash sync. 1/4″ or 1/8″ phone connectors are a reliable, inexpensive substitute. Attaching wires to phone connectors takes a bit more skill than attaching HH connectors, but it’s worth the extra effort. Another idea is to switch to coaxial (audio) cable; this is the cable used by guitar players, and solderless plugs and cables are available here.

An even better idea is to use a wireless system. The newest Nikon digital SLRs and shoe-mount strobes, for instance, have a reliable optical wireless system built into the equipment. For greater range, radio remotes from Pocket Wizard and other manufacturers are available. Wireless systems also eliminate the trip hazard associated with running sync cords across the floor.

If you are considering the purchase of new studio strobe equipment, I suggest that you rule out the purchase of equipment from manufacturers such as Novatron and Dyna-Lite, mentioned above, who continue to sell equipment with HH connectors. Many excellent strobes are available from manufacturers who do not sell equipment with HH connectors, including, but not limited to, Norman, Profoto, and the popular Alien Bee and White Lightning units from Paul C. Buff.

If you have existing strobe equipment that requires the use of a two-prong HH male plug, I suggest —

  • Make or buy the shortest possible adapter cord with a HH plug on one end and a 1/4″ (or 1/8″ if you prefer) female phone jack on the other.  
  • Insert the HH plug into the strobe, then glue it in place using epoxy glue, silicon caulk, or other strong adhesive.
  • If this does not appeal to you, then install a warning tag on the adapter cord, and purchase a HH female connector. Whenever the adapter cord is not plugged into the strobe, plug it into this “dummy” connector. If you are especially concerned about preventing access by children, locking caps for HH male plugs are available from electrical supply companies.

In Conclusion - Two Hypothetical Scenarios

Joe Foto, recently retired, is a serious amateur photographer. His camera is a Nikon D-200, and he recently purchased a Norman studio strobe unit. The Norman strobe has a 1/4″ monaural female phone jack marked “sync”. Joe wanted to connect his camera directly to the strobe to obtain 100% reliable triggering.

By following instructions he found on the internet, Joe built an inexpensive do-it-yourself sync extension cord using a HH female connector on each end.

Joe also needed an adapter cord at each end of this extension cord. For the camera, he purchased a cord with a Nikon screw-lock PC male connector on one end and a HH male plug on the other end from Paramount Cords. He made the second cord, with a 1/4″ male phone plug on one end and a HH male plug on the other, with parts from Radio Shack. Because he had extra wire, he made the second adapter cord five feet long.

Several months ago, Joe’s daughter and son-in-law came to visit. Joe loved his grandchildren – Bobby, 5 years old, and Amy, 13 months. On the second day of their visit, Joe was setting up a light tent to photograph a collectible item he planned to sell on eBay. “Grampaw, can I help you?” “Sure, Bobby, just ask me before you touch anything.”

Bobby saw a plug on the floor. He knew what to do with it – he had seen his mommy plug in the vacuum cleaner many times, and his daddy plug in a hand drill. So he plugged it into the wall outlet.

Ten minutes later, Joe’s daughter entered the rec room, setting little Amy on Joe’s always-spotless floor. “So how’s it going, Dad?” “OK, honey, how’s work?” They talked while Amy crawled on the floor. Amy saw something shiny and pretty on the floor – the energized 1/4″ male phone plug – and put it into her mouth.

“SPRINGFIELD, May 25. Exclusive to The Courier-Herald. Amy Jo Smith, born April 15, 2005, was fatally injured on May 20th at the home of Mr. and Mrs. Joseph Foto, Springfield. Amy was the daughter of Mr. and Mrs. Sam Smith of Atlanta and the grand-daughter of Mr. and Mrs. Foto. The child’s death was caused by a malfunctioning electrical cord. The Springfield county coroner has ruled the death an accident.”

I prefer the alternate scenario: After reading internet instructions for a sync cord using HH connectors, Joe shook his head and thought, “Why would anyone recommend building something so dangerous?” He made his own sync cord using 1/4″ phone connectors, and they all lived happily ever after.

Addendum

My refusal to back down on the important issue of household plugs in strobe sync cords resulted in my banishment from the Strobist website and the Strobist group on Flickr.

Quite by coincidence, soon after I was banned from Strobist, I read a book entitled The Storm*, which explains in detail how the New Orleans flooding from Hurricane Katrina could and should have been prevented. On page 4, the principal author, Ivor van Heerden, wrote these words: “I am a disaster science specialist and hurricane researcher who tends to wear his heart on his sleeve. I rarely hold my tongue. I rarely see good reason to, and certainly not in this case. As a scientist, I champion a reality-based view of the world, old-fashioned as that may be …” And on page 54, he states, “But if just one person was saved by all our hard work - just one child - then it was worth it.”

I do not mean to imply that my small effort is equivalent to Dr. van Heerden’s much larger one. I did find his words and attitude to be the same as mine, and I’m proud that I did not back down.

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* van Heerden, Ivor, and Mike Bryan, “The Storm - What Went Wrong and Why During Hurricane Katrina - The Inside Story from one Louisiana Scientist,” Viking/Penguin, 2006. ISBN 0-670-03781-8.