Surveillance Videography Using DSLR Cameras
Written by Raymond Siljander   

In most instances, photographs feature better detail than video images. Additionally, the surveillance specialist can record photographs under a lower level of illumination than is possible when recording video. Nevertheless, many cases require video evidence. This discussion addresses surveillance videography using video-enabled digital single-lens reflex (DSLR) cameras.

At the time of this writing, two relatively recent technologies have revolutionized surveillance videography. They are DSLR cameras that record high-definition (HD) video and AstroScope Night Vision Modules that mount between DSLR cameras and the lens. These two technologies provide a greatly enhanced surveillance videography capability.

Today, an increasingly challenging world requires that surveillance specialists have the ability to record high quality video under varied conditions (for example, from short distances under subdued lighting and from extreme distances day and night). A superior standoff capability increases vantage point options and it minimizes the likelihood of detection by the subject. This is important for prolonged stationary surveillance operations and when subjects are wary and dangerous.

Surveillance specialists commonly use consumer-grade camcorders because they are reasonably priced, efficient, user friendly, and suitable when range is limited and lighting is good. This class of camcorder is ideal for fast moving situations that require spontaneous video capture with no time for setup.

When circumstances permit using a modern HD consumer camcorder, the specialist should use them. Indeed, credible sources confirm that this class of camcorder provides video quality that is equal to or better than professional camcorders provided only a few years ago. Unfortunately, for surveillance, consumer camcorders suffer limitations, including:

  • Poor performance under low light conditions.
  • Poor performance when used with an image-intensifier night vision device (NVD).
  • Limited standoff capability—that is, the maximum distance allowed for recording detail such as subject identification (facial recognition) and legible vehicle number plates (license plates). A consumer camcorder at full zoom with a teleconverter lens provides a standoff capability of only about 300 yards (274 meters). Naturally, circumstances affect distance.


Today, surveillance specialists can manage low-light conditions and extreme distances by recording video using a DSLR camera with a fast lens or with a high-magnification lens. To appreciate the benefit of recording video using a DSLR camera with a telephoto lens, compare the following video capture systems:

  • Canon VIXIA HF M400 high-definition (HD) consumer camcorder with the 1.7x teleconverter lens.
  • Canon or Nikon DSLR camera with the 200mm f/2.8 telephoto lens.

At full zoom with the teleconverter lens in place, the camcorder provides a focal length and f-ratio of 103.7mm f/5.1. In contrast, a DSLR camera with the 200mm f/2.8 lens provides approximately 1.9 times greater magnification and it is almost 2 stops faster. In addition, the large image sensor in a DSLR camera performs better under low light conditions than the small image sensor in a camcorder. The large DSLR camera sensor also permits using greater magnification without narrowing the field of view to an intolerable extent. When maximum field of view is important, use a full-frame rather than a crop-sensor DSLR camera.

Video Enabled DSLR Cameras

The introduction of video enabled DSLR cameras revolutionized surveillance videography, and the cameras continue to improve. Some of the benefits provided by these cameras include the following:

  • DSLR cameras permit recording video using dedicated lenses, some of which are very fast (large aperture), and some provide high magnification.
  • DSLR cameras permit recording video using refractor telescopes, most of which are considerably less expensive than name-brand telephoto lenses of comparable focal length.
  • DSLR cameras permit recording video using extreme magnification Schmidt-Cassegrain telescopes.
  • DSLR cameras permit recording video under lower light conditions than is possible when using a consumer camcorder. This is because DSLR camera image sensors perform better under low-light conditions than camcorder sensors do and because faster lenses are available for DSLR cameras.
  • DSLR cameras perform well with the AstroScope Night Vision Module.

Before proceeding, understand that today the surveillance specialist can record useful video from previously unimaginable distances. For example, recording video during the day and at night from a distance of 0.50 mile (0.80 kilometer) does not begin to challenge the range potential (environmental and other variables permitting).

Short Range Low Light Videography

Figure 1—Images from video recorded in the same barroom but from two different seating locations, using a camcorder with an f/3.6 lens. The lower image was recorded using a Canon Rebel T3i DSLR camera with a 50mm f/1.4 lens (faster than the camcorder lens).

Figure 2—This in-house created purse-cam enables female surveillance specialists to discretely record video from short distances while seated.

Figure 3—DSLR cameras work with dedicated telephoto lenses and with telescopes. Photo by Lance Juusola

FIgure 4—Images extracted from video recorded from a distance of 650 yards.

FIgure 5—Nighttime video recorded from a distance of 330 yards using the Canon Rebel T3i DSLR camera and Canon EF 400mm f/5.6 telephoto lens.

Figure 6—Standard AstroScope Night Vision Module located between teh Canon DSLR camera and the 300mm f/2.8 telephoto lens. Sofradir EC Inc., formerly Electrophysics, manufactures and markets this AstroScope: www.nightvisioncameras.com

Morovision Night Vision, Inc., a distributor of night-vision products, sells various AstroScope models as well as other night-vision products. www.morovision.com

Photo by Lance Juusola

Figure 7—This long-range night-vision videography and photography system features teh SOBA AstroScope, Canon Rebel T3i DSLR camera, and 1500mm f/10 Celestron C6 Schmidt-Cassegrain telescope. The PVS-14 image intensifier night-vision device mounted to the riflescope via the PVS-14 Adapter serves as a finder scope, which permits quickly locating distant subjects. The PVS-14 Adapter is available from Micro-Times LLC: www.lensadapter.net

The pan/tilt fluid head on the Kirk Multi-Purpose Window Mount in the lowpod position supports the apparatus: www.kirkphoto.com

This SOBA AstroScope is compatible also with refractor telescopes.

Figure 8—Long-range night-vision images (recorded as stills). Upper image recorded from 0.54 mile. Lower image recorded from 0.27 mile. Images recorded using the third-generation SOBA AstroScope Night Vision Module with a DSLR camera and 2350mm f/10 Celestron C9.25" Schmidt-Cassegrain telescope.

 

When circumstances permit using a consumer camcorder, surveillance specialists should use them because they are inexpensive, small, user friendly, and efficient. However, under low-light conditions, a video-enabled DSLR camera with a fast lens provides better results (Figure 1).

In most instances, camera concealment is necessary when recording short-range video. Some concealment containers such as women’s purses are gender specific (Figure 2). Other containers such as tote bags, messenger bags, and backpacks are gender and location neutral.

A surveillance team enjoys advantages that the lone operative lacks and women tend to have an advantage over men. In many instances, when two women will do short-range video surveillance, one should dress up while the other dresses down. The objective is for one woman to be striking and noticed while the other is quiet and drab in a way that permits her to go unnoticed or at least escape interest. After the initial scrutiny that occurs when they enter a location they become part of the landscape, figuratively speaking. From then on, the “drab” woman can go unnoticed while discretely recording video. Sometimes both women should be nondescript. When planning and executing a surveillance operation, always consider human nature and take advantage of it. Never underestimate the power of stereotypes and human bias.

Daytime Long Range Videography

Video enabled Canon and Nikon DSLR cameras accept dedicated telephoto lenses provided by camera manufacturers. They are also compatible with refractor telescopes and Schmidt-Cassegrain telescopes (Figure 3). Telescopes mount to DSLR cameras by means of the direct coupling method, also called the prime-focus method.

Using a DSLR camera with a refractor telescope saves money because they are less expensive than name-brand telephoto lenses of comparable focal length. Using a DSLR camera with a high magnification Schmidt-Cassegrain telescope permits recording video from extreme distances (Figure 4).

Usually, the atmosphere more than the capability of high magnification optical systems limits standoff distance. Indeed, high-magnification telescopes can reach farther than the atmosphere usually permits. During extreme-distance videography, near-ground thermals (heat waves) present the greatest challenge. Thermals badly degrade image quality but because they are most severe near the ground, elevating the camera minimizes their detriment. Thermal activity varies by region, season, and terrain. For example, the surveillance specialist can record usable video from greater distances during cold winter months than during hot summer months, and from greater distances over water than over barren earth. An elevated vantage point is always preferred.

Nighttime Available Light Videography

Modern DSLR cameras perform surprisingly well under low-light conditions. In the urban environment, the level of nighttime artificial illumination often permits recording quality video, especially when using fast optics and in some instances, not-so-fast optics (Figure 5). A lens is fast when it features a large aperture relative to its focal length. For example, the Canon and Nikon 60mm f/2.8 close-up lenses are slow while their 400mm f/2.8 telephoto lenses are extremely fast.

Night Vision Videography

In their book Clandestine Photography (2012), Raymond Siljander and Lance Juusola (pp. 296-297, 298) explain that, “Night vision photography is the recording of photographic images at night using an image intensifier NVD to increase image brightness. Unfortunately, too often, a surveillance specialist acquires an NVD, couples it with a camera or camcorder, records some nighttime images, and finds image quality disappointing. Night vision photography involves more than simply mounting an NVD to a camera or camcorder and recording images in the usual manner... The specialist must understand characteristics unique to image intensifier night vision photography because it is very unforgiving.”

The AstroScope Night Vision Module, which is the most user-friendly system available, mounts between DSLR cameras and lenses. The standard AstroScope is compatible with dedicated electronic lenses such as Canon and Nikon (Figure 6). The Special-Order Battery-Adapted AstroScope (SOBA AstroScope) works with non-electronic lenses such as telescopes (Figure 7).

Third generation (Gen 3) night NVDs feature a brightness gain of approximately 40,000x, which represents an advantage of about 8-10 f-stops. The AstroScope has a broader spectral sensitivity range than most unmodified DSLR cameras and includes the near-infrared range. The night sky is rich in near-infrared radiation, so the broader spectral range can enhance night sensitivity. Additionally, invisible near infrared illuminators permit further enhancing sensitivity. Resolution of a Gen 3 NVD is 64 lp/mm typical (57 lp/mm minimum). The resolution of a Gen 3 NVD is comparable to that of a 3 megapixel digital camera, which provides excellent images when technique is good and atmospheric conditions are favorable (Figure 8).

Apparatus Stability

When recording video and photographs using high magnification, stability of the apparatus is essential. In addition, operate the camera using a remote control. Apparatus movement blurs photographs and it causes objectionable image movement when recording video. A conventional tripod head usually is suitable when recording photographs. When recording video, use a geared head or pan/tilt fluid head. Circumstances determine when a geared head is appropriate and when a pan/tilt fluid head is required.

Knowledge, Experience, Creativity, and Motivation

Surveillance videography is an advanced and sometimes complicated application of photographic and related principals. Indeed, it involves more than a surveillance specialist sitting in a vehicle with a consumer camcorder in hand. Knowledge, experience, motivation, and appropriate equipment are prerequisites to creating a quality work product under diverse conditions.

Unfortunately, as important as this craft is, formal training opportunities are almost non-existent. Academia provides no training and neither is formalized in-house training available, especially for advanced methods. Fortunately, by special request, Team Guardian Investigation and Security Specialists will provide advanced surveillance videography and photography training (www.teamguardian.us). As for those who cannot attend personalized hands-on training, realize that a person can learn a great deal and develop a high level of expertise by means of self-directed study, by reading authoritative materials, and experimenting.

During study and experimentation, think creatively and try new things. Try anything that logic suggests may work, and try things that perhaps will not work. When writing the book Clandestine Photography the authors tried many things that convention suggested would not work, but many of the things did work. In fact, some unorthodox and hybrid methods worked surprisingly well. One example is using a tele-extender and focal-reducer together, a concept that sounds absurd but that works surprisingly well and has a legitimate application during long-range night vision photography and videography.

Remember the statement made by the American inventor Thomas Edison, “I have not failed. I’ve just found 10,000 ways that won’t work.” The tendency is to recognize the value of knowing what works but fail to see value in knowing what does not work. Knowing what does not work is necessary during problem solving and when upgrading the craft. During the Cold War, countries that acquired technology by means of espionage succeeded in obtaining a lot of information but they failed to learn what the researchers discovered did not work. Consequently, espionage provided only a measure of useful information, a circumstance that left them at a disadvantage militarily, with a diminished ability to advance the science, and with fewer products having a commercial application to strengthen their economy.

About the Author

This e-mail address is being protected from spam bots, you need JavaScript enabled to view it ’s occupational history includes a variety of manufacturing and service industries, the insurance industry, industrial security supervision, licensed private investigator doing general and undercover investigations, licensed process server, and law enforcement as a certified police officer graduating first in his class in the police academy. He is the author and coauthor of 16 books addressing various police science and related topics, including Clandestine Photography: Basic to Advanced Daytime and Nighttime Manual Surveillance Photography Techniques (2012, Charles C Thomas Publisher Ltd.).

 
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