Dealing with Low Light ProblemsBy Brian Rhodes, Published on May 09, 2012
Getting high quality images in low light is a common challenge. With the problem being so widespread, we were curious to understand how integrators normally address the issue. In our latest integrator survey, we asked "How do you know if a camera location will have problems in low light? What do you do?". In this note, we dissect and analyze those answers, grouping them into 6 major themes of integrator practice.
The chart below describes common techniques integrators use to assess this issue:
Readers may notice that the sum of all percentages above exceed 100%. Many responses indicated integrators use more than method to address this issue. While one technique may be favored over the other, only 7% of the answers listed a single method for determining how to address low-light situations.
Analysis of the answers groups them into the list below:
- Detailed Site Survey
- Special Cameras
- Dead Reckoning/Experience
- Lightmeter Readings
- Improve External Illumination
- Test Scene with Camera
While the responses were gathered from a group of integrators located throughout the globe, no strong regional preferences were noted.
Detailed Site Survey
Integrators most frequently mentioned site surveys to identify low light problem. This strength of this answer indicates the value of walking the job when specifying a video system. Many integrators noted that a site survey, coupled with experience and taking light measurements, was the preferred method of assessing low-light areas.
- "Our surveys always include a night time evaluation with light meters to determine the low light needs"
- "Check lighting during day and night time conditions. "
- "We visit the site in night time hours and measure the amount of available light."
- "We always inspect the area before offering."
- "An onsite survey is conducted and measurements are taken."
- "for a real test you have to visit site at night and rate the light quality"
- "Look around to see if there is any obvious lighting street lights or security lights, sometimes if I'm unsure I go back at night."
- "We know this from experience and site surveys."
- "This is generally determined during the site survey"
- "For outdoors in extreme cases we have gone out at night to see what the lighting actually looks like."
- "Through ocular inspection or site survey."
- "we ask questions and observe the location."
- "A site survey or the application will tell us if we need to record in a low light area."
The second more common answer was that integrators automatically specify 'low-light' specialty cameras for areas that might be a problem. A myriad of technologies are marketed as giving surveillance cameras extra performance in low-light scenes. Using cameras with integrated IR was mentioned most often, followed by low-light specialty technologies (e.g.: Axis 'Lightfinder'). Interestingly, only two responses mentioning 'thermal' type cameras as the go-to option.
- "We usually install IR dome or bullet type cameras"
- "Inside we will utilize IR's more frequently in areas that are not able to be lit otherwise. Exteriors we will use IR's but less frequently."
- "We use lightsensitive cameras or IR lightning"
- "Most cameras we install are going to have integrated IR."
- "We will go with a camera with built on infrared lights"
- "We prefer to use ultra low lux cameras with flood lights for best image quality"
- "I would use IR cameras and if that is not enough would add IR illuminators"
- "[We] pick the right camera model that will do the job"
- "If low light or difficult contrast situation, you have to go with a more expensive IR or quality wide dynamic range camera."
- "I normally will just use a DH160 because they do amazing at night"
- "Lately we have been having success in low light areas with the Axis Light Finder Q160X cameras."
- "Generally rely on manufacturer's specifications. Lean toward IR cameras when outdoors or low light environments."
Not surprisingly, many integrators suggest they rely on the depth of their experience to guide product and solution selection. While these answers did not exclude using other methods to decide how best to assess or address a problem, already being familiar with identifying and addressing low light issues is an especially valuable skill. Field experience clearly plays a important role for integrators assessing these areas.
- "Experience is the key here. I personally have 24 years to my name and can look at a site in the day time and make a reasonably accurate assessment of what the night time will be like."
- "We normally have a vague idea of what to use, but we normally try 2 or 3 models with wrist screen on-site so the costumer can see what pleases him."
- "How? Experience."
- "Experience, try to judge how much light a camera will receive at night "
- "Usually you will know by just looking at the area in question"
- "We know which cameras operate best in low-light conditions from our own product trials and so we will choose the most appropriate camera for the application."
- "We have done allot of testing with specific cameras in specific locations."
- "Through inspection and estimation based on experience"
- "We don't use light meters, just common sense."
- "Rely on personal experience to determine if IR is appropriate."
- "We primarily go by the "human-eye" test."
- "Select camera options that have adequately resolved the issue in the past."
The most quantitative method of gauging low-light was by use of a light meter or luxmeter instrument. However, difficulty in taking homogeneous light samples, the inconsistency of corresponding manufacturer lux ratings, and over-reliance on a tool (ie: diminishing the importance of experience) are risks that must be considered when using these instruments. The use of a light meter was often cited as part of the solution, but seldom given as the 'only' solution.
- "we usually take a standard light-meter to determine what the lux will be in the area"
- "Use a lux meter for night."
- "measure using a measuring device"
- "Take measurements with a lux meter to confirm."
- "We visit the location at night and measure the Lux level "
- "if challenging then we will measure with LUX meter."
- "Use a light meter"
- "USING A LIGHT METER IF NOT SURE."
- "We use a light meter."
In a follow-up question, we asked these integrators 'How do you use your light / lux meter?' The feedback that followed was surprising. As a result, we plan to release a separate report titled "Integrator Use of Lightmeters Examined" elaborating on this topic.
Improve External illumination
Some integrators noted that they prefer simply to supplement poor lighting with additional illumination. These answers mentioned both infrared illuminators or supplemental 'white light' as a possible solution, with no clear preference between types noted. In some cases, adding (high-voltage) 'whitelight' is a cheaper option, but adding an IR illuminators often fall under the purview of the (low-voltage) integrator. The majority of responses indicate integrators are willing to work with whichever option the customer is willing to pursue.
- "I look at it in the night. If it is really dark, I figure out where to put a floodlight or IR - depending on the location."
- "if the job has the budget we are going to start proposing separate IR illuminators for exterior applications."
- "We always install IR illuminators if there might be any issues with low light."
- "If more light is needed outdoors we recommend extra IR illuminators or visible light"
- "Add IR or white light illumination"
- "We include infrared illumination with the proposal or add an allowance to contract with an electrician to add traditional security lighting to alleviate the issue."
- "if there is an issue we use IR iluminators."
- "For unique applications (like utility substations), where we know lighting will be an issue, then we use IR illumination."
- "As much as possible, we try to work with customers to add visible light sources. "
Test Scene with camera
A small, but still significant, number of responses indicated a strategy of 'testing' low-light performance with an actual camera and observing performance. We suspect this method results in meaningful testing results, but it requires the integrator to manage their own testing program and carry inventory of test equipment.
- "Test the camera first before I recommend it. Keep testing till I find the right solution"
- "We make some tests, with some cameras we own for demos or testing"
- "When i am doing a site survey, i typically have a camera with me and can tell what the lighting will be like."
- "Often we deploy a camera with hybrid IR / white light illuminator to conduct a test."
- "We generally take a demo camera with a "wide dynamic range" to the site and test it."
We have found this approach is easier when using the proper equipment. For example, using portable power, laptop/tablet PCs, and an IP camera can make quick work of these types of tests. In our Veracity PointSource note, we examined how we use a similar setup for doing camera review field tests.
See our short video review of the sub $200 PointSource unit below: