Nighttime Accident and Crime Scene Photography "Painting with Light"
Investigator Robert E. Kramer - Crime Lab
220 Clay Street
Cedar Falls, IA 50613
Photographs taken at the scene of a traffic accident or crime scene are a most critical part of the investigation. Most law enforcement investigators are familiar with the term: "...a true and accurate depiction of the scene..." To truly capture the nighttime accident or crime scene, it is important that the law enforcement personnel assigned the task of photography understand more than just the basics of camera operations so that photographs taken will truly represent the scene as it was at the time of the investigation. It will be the purpose of this article to address many of the problems facing the law enforcement photographer responsible for nighttime photography. Since this article will deal with the specific technique of painting with light, a basic knowledge of camera operations and accessory functions is necessary.
Olympic competitors are confronted with difficulty factors as they perform their gymnastic and diving exercises. It could be argued that the most novice of swimmers could stand at the edge of a three meter board and complete a simple dive into the pool with some degree of grace. The same can be said for the beginning photography student. Simple photographic situations such as those during the daytime with a bright sun and high sky are easily mastered. It's when a factor such as steady rain, heavy snow, a low bright sun on the horizon, or nighttime is encountered that the photographer is truly put to test. My experience has found that the nighttime scene is one of the more challenging scenes to photograph, particularly when skid marks other evidence is scattered over a great distance. Simply put, the camera does not see what you see. Have you every stood outside under the stars and noticed that, up to a certain point, you tend to see more clearly as time passes? Your camera cannot do this. The adjustments you as the photographer make in such things as camera position, time of exposure, and supplemental lighting will be the deciding elements as to whether your camera will be allowed to "see" as you do.
The key to any law enforcement investigation is to be prepared, and photography is no different. Preparedness includes necessary training, but classroom time needs to be followed with equipping the student with the proper tools. For this reason, the following items are suggested as essential to any camera kit, and in particularly, one to be used for nighttime accident and crime scene work. The function of each item, and reasons for being crucial in nighttime accident photography will be discussed in detail.
1. It is important that the camera kit include a manual camera with adjustable shutter speeds and a "B" (bulb) setting. This setting allows the shutter to be opened for an indefinite period of time, which allows for time exposures of as long as the photographer deems necessary. It has been suggested many times that an automatic camera can be used so that time consuming camera adjustments can be held to a minimum at the scene. I argue against this point for two main reasons. First of all, the automatic camera is at its best when the existing light at the scene enables the built-in metering system to make adjustments of the f/stops and shutter speed. The key words here are: existing light. In nighttime photography there is little or no existing light. Nighttime automatic in-camera adjustments are impossible, making the need of a manual camera a must. Secondly, by mastering the basics of shutter speed and f/stop adjustments, the photographer will come to better appreciate the importance of these two necessary steps in nighttime photography. With this understanding and practice, adjustments of the camera and lens at the scene will be as systematic as removing the lens cap.
Digital or Film?
Considering all the factors with nighttime photography such as proper exposure, camera position, the number of flashes needed to illuminate the scene, and difficulties such as stopping traffic, it’s hard to imagine that the photographer needs to consider yet one more thing - will it be digital or film photography? The introduction of digital media is a very good example of how technology can help us do our job even better. By no means am I going to stand in front of class and tell students that it’s time to dispose of the 400 speed film in their camera kit in favor of digital media, but the benefits of digital photography in difficult situations are many, and they include …
- A good digital camera is versatile and user friendly. The digital camera I use for over nearly all of my crime scenes looks and feels like 35mm cameras I have used for over thirty years. It is durable, accepts a wide range of interchangeable lenses, has adjustable shutter speeds, a shutter release receptacle, and best of all, I was using it without difficulty the day after our agency purchased it. In short, the switch was simple.
- Digital enthusiasts agree that instantaneous results are
a plus, particularly in law enforcement work. Look for
a digital camera with an LCD screen which will allow you to
view your photo immediately.
A word of note: time exposures are very large files and can take up to thirty seconds to appear on the screen. The process that your camera takes to bring such images on to the screen is a tremendous drain on battery longevity.
All digital cameras good for technical crime scenes are in the 5 to 7.5 mega pixel range, and they take terrific pictures. Look for a camera which offers a capture of at least 5 effective megapixels. Make no mistake, digital pictures at law enforcement standards are huge files. Whereas typical point-and-shoot digital cameras can take many pictures on a 16 mega byte card, higher resolution images can be in excess of 2.5 megs each. Consult your state crime lab, or any other laboratory who may be processing and analyzing your images and evidence. I know of at least a few state crime labs demanding a minimum of 1024 X 768 resolution. At that resolution, one can easily see and understand the necessity of a high-end digital camera.
2. A normal lens with adjustable f/stops makes a perfect match for the manual camera. Whereas the camera houses the shutter, the lens itself contains the aperture. The aperture within the lens controls the amount of light which is allowed to pass through the lens and be captured on the film or digital media. This control is made possible by f/stops which range from f/2 (a very wide aperture opening,) and f/22 (a narrow opening.) The term depth of field is familiar to most photography students, and it is a word which scares many off to another discipline. Simply put, depth of field is the amount of the scene (distance in front of the camera from its closest to farthest points) which is in focus. Depth of field can be a major concern in nighttime photography, (this will be explained later), and the photographer should understand that setting the lens aperture at f/2 will yield very little depth of field, and f/22 will dramatically increase the amount of depth of field.
3. A remote cable release is necessary so that the shutter can be "tripped" without having to touch the camera. Painting with light is done with very long exposures (sometimes as long as several minutes) so it is very important that the photographer take all steps to eliminate camera movement.
4. The camera will be mounted on a tripod during the photography and, with the cable release, will help eliminate the unwanted camera movement. When buying a tripod, look over the options. Be prepared to purchase a one which will survive the wear and tear which it will receive by bouncing around in the trunk of your car. Make sure it is sturdy enough to withstand a stiff breeze, and pay attention to the leg adjustment controls. Experience has shown me that the old fashioned screw-type collars are not as durable as the clamp controls which I see on some of the newer tripods. And one more thing, make sure the tripod has a camera base (where the camera attaches to the tripod) which allows for full movement of the camera in tilt forward and tilt back, as well as left and right directions.
5. A powerful external flash will be essential in illuminating skid marks and other evidence at a nighttime accident or crime scene. How much power is necessary? Without getting into details on explaining a flash guide number, a visit to a reputable camera store is suggested. Explain to them what you plan to do, and they will steer you toward a good flash unit. Be prepared to spend $200.00 or more. And remember ... this same flash unit can be used during routine flash photography at distances as close as a few feet. Spending money to buy a good flash unit will make flash photography of both the basic and technical scenes possible.
6. A rechargeable external battery for the flash is optional, but strongly suggested. Painting with light involves illuminating the scene with multiple flashes. Since several angles of the scene may be photographed, it would not be unheard of to illuminate a scene with twenty or more flashes on full power output. The external battery recycles quickly and holds considerably more power than the standard nicad or lithium batteries. Brand names are not important, but the battery pack I have has been known to yield in excess of three hundred flashes on a single charge, so it is easy to see the benefit of such an accessory.
Learning by Trial and Error
Painting with light is easily mastered with proper preparedness and practice. You wouldn't wait until the day on which you are encountered with a string of safe burglaries at mall stores to learn proper latent fingerprint techniques would you? If sometime in the future you may be called upon to take nighttime accident of crime scene pictures, now is the time to prepare yourself for the task by realizing the special considerations which will be encountered. It has already been mentioned in this article that the camera does not see what your eyes can. You, as the photographer, need to help the camera to see by supplementing existing light at the nighttime scene with artificial lighting, an extended time exposure, or a combination of both.
When teaching recruits, I assign students to take a number of photographs as they study the section on Painting with Light. One of the first photos taken is done in a nighttime outdoor setting of a subject matter fifty feet away from the camera position with a shutter speed of 1/125th second and an f/stop of f/8. The student has the option to have street lights or other existing light present in the area. When these initial photographs are viewed, many of the students comment that they could easily see the subject matter being photographed when the picture was taken, but that it was not visible in the print. If the subject matter was an automobile, they were possibly able to see light reflecting off a license plate in the print, but the car itself was lost in the dark background. What a perfect illustration of the point I'd been trying to make to them!
A follow-up photo in the assignment would be to take a picture from the same location, looking at the same subject matter, using the same camera settings, and illuminating the scene with one flash from any flash unit they may have brought to class with them. The finished photos were again, usually very dark, with the subject matter considerably underexposed. Some of the students were sometimes heard commenting that they thought their flash was good for a distance of up to fifty feet. The point made here was two-fold. Again, as they took the picture it may have appeared that the scene was illuminated with the single flash. This is not always the case, as again, the eyes of the photographer were more sensitive to the flash going off than was the camera. Secondly, the photographer should never assume that just because the flash may have an automatic or manual range up to fifty feet, proper exposure of subject matter at that distance will be obtained. Never assume that the effective range of your flash will be as stated by the manufacturer. My best advice to all photographers is to perform tests with flash units to be used on the job. Test the effective range on all automatic settings as well as full-manual output.
Nighttime photography, particularly of areas or scenes covering a large area requires proper planning, as well as the execution of available resources. I, for one, understand that the unexpected is nearly an everyday factor in my job. I also know that realizing one’s limitations need to be factored into the nighttime photography assignment. We have already outlined the need for specialized equipment such as the camera, flash, external battery, etc. In addition, the suggestion was made that the photographer should become well acquainted with the equipment prior to the job, and one way suggested was for the photographer to subject themselves to test photos. One also needs to be prepared for the unexpected by realizing problems that can occur at a moments notice, and the best way to understand certain problems is to look at an assignment.
This scene involved a shooting, with the reporting time being shortly after midnight. One of the first things you will note when observing the photo is that there was snow on the ground. This early morning was particularly cold, with a stiff north wind. Cold temperatures bring out some of the worst in cameras, flash attachments, and accessories. For example, extreme cold temperatures reduce battery life considerably. If you are using a digital camera, battery life can be cut even more than with film cameras, so be prepared! Always have extra batteries on hand, both for the camera and flash unit. I was in this profession for a very short period of time when I first realized that from November through March, I needed to bring my camera kit into the house when I come home from work every evening. Not only does this simple step prolong battery life by storing the camera and equipment out of the bitterly cold Iowa winter nights, but it also reduces lens condensation. If cameras could talk, they would tell you that (unlike us) they don’t mind being brought from a warm environment into a cold one, but hate being brought from the cold into a warm house or crime scene. At this particular crime scene, as is the case with any nighttime crime scene in the winter months, I realized that I would have to work quickly, as I wanted to be sure that my equipment would stay fresh.
A factor yet to be covered until now is one of the most important: cooperation. Two victims had already arrived at the hospital by the time that I arrived on the scene, and patrol officers had roped off the immediate area with traffic cones and police barrier tape. Pedestrian and vehicular traffic was eliminated almost immediately. I took several minutes to first scan the area for temporary or otherwise fragile evidence, documented it, then proceeded with the photography. This particular photo was taken looking toward a door out of which both victims and suspects exited a building and walked to the south (right.) With my camera on the tripod, I opened the shutter and illuminated the scene quickly with eight to twelve bursts of flash on full manual output as I walked away from the camera (and out of view) to the north (left.) Quickly walking back toward and behind the camera I then fired several bursts as I walked across the street in almost a direct line parallel to the traffic cones seen in the right side of the photo. This resulting photograph was particularly useful to fellow members of our Detective Unit, in that we could place parties involved on the sidewalk and surrounding area. This particular photo was taken with a total of twelve to fifteen bursts of flash and an approximate 60 second time exposure at f/16. (Since many painting with light scenes involve great distances, it is best to use a small aperture setting which yields greater depth of field.)
This accident scene required quite a bit of cooperation and patience of many law enforcement officers. This four lane divided highway is heavily traveled even during the nighttime hours. After the accident, officers blocked traffic from the north (top of photo and around the “S” curve) as well as from the south at an intersection approximately ¼ mile south of the scene. Of special interest were tire tracks from the southbound car in the grassy median, made prior to coming into contact with the motorcycle driver. With the camera on the tripod, I opened the shutter and walked briskly to a point approximately one-hundred feet north of the motorcycle in the ditch adjacent to a fence line which can be faintly seen to the right. Firing approximately ten bursts of flash toward the street, I walked back toward the camera. I then again quickly walked to a point north of the motorcycle and walked back toward the camera, and you can see evidence of the four bursts of flash I fired as I approached the area of the motorcycle. I was somewhat unsatisfied with the bright hot spots as result of the final four flashes which were fired toward the median, but at the same time realized that they illuminated the tire tracks in the grass rather well. I was equally satisfied that the bursts of flash fired from the ditch did a terrific job of illuminating the curvature of the road.
- When painting with light at long, or scenes with "depth" ... it is the important to begin the bursts of flash at a point away from the camera and walking back toward the camera on the tripod. Subsequent bursts of flash as one approaches the camera tens to cover any “ghost images” of the photographer which may have been left as they walked about in the scene with the camera shutter opened.
- In addition, scenes with "depth" such as long tire marks as seen in the photo above, require a smaller aperture opening, such as f/11 or f/16. These settings will allow for capturing more depth of field.
I've been around law enforcement long enough to believe that nothing in this line of work will intimidate me so much that I would be afraid to try it during an actual investigation. Anyone can sit in a classroom and look at photos on a screen which illustrate a technique being explained by the instructor. It takes dedication to apply skills learned in the classroom and mastered during practice in order that they are performed as routine "in the field." I encourage each and every one of you to take the time to familiarize yourself with the technical aspects of your job ahead of time.
A native of Waterloo, Iowa, Bob Kramer has been a member of the Cedar Falls Police Department since October, 1974. He served on all Patrol Shifts prior to being assigned to the Investigative Unit as supervisor of the Crime Lab in June, 1980. During his assignment in the Crime Lab, he has received specialized training at the FBI Academy on three occasions, as well as at the Federal Law Enforcement Training Center in Glynco, GA. He has been a member of the International Association for Identification (I.A.I.) and Iowa Division of the I.A.I. since 1982. He has served the Iowa I.A.I. as President, and is currently Editor of the Iowa I.A.I. publication: 4N6.
A graduate of Upper Iowa University with a B.S. degree in Public Administration, Bob is certified by the Iowa Law Enforcement Academy (I.L.E.A.) as an instructor in the areas of Crime Scene Mechanics, Law Enforcement Photography, and Fingerprinting. He regularly teaches on behalf of the I.L.E.A. at recruit classes, and conducts other specialized training on crime scene photography.
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