How to Choose an Infrared Camera
The top performers in our review are the FLIR E60, the Gold Award winner; the Fluke Ti400, the Silver Award winner; and the FLIR E50, the Bronze Award winner. Here’s more on choosing a system to meet your needs, along with detail on how we arrived at our ranking of infrared cameras.
Infrared cameras, also called thermal imagers, allow you to capture important information that is usually invisible to the naked eye. Standard digital cameras capture and display information from the visible portion of the electromagnetic spectrum. Infrared cameras, on the other hand, use special IR-sensitive sensors to detect differences in temperature and represent them visually.
Objects with a high temperature generally emit higher levels of black body infrared radiation. By detecting these elevated levels of radiation, infrared cameras provide accurate representations of thermal characteristics. Why is this useful?
Thermal imagery allows you to detect and address problems that would otherwise go unnoticed. It allows engineers and electricians to spot overheating components, locate overloaded circuits and fix problems before they get worse. Building inspectors and home energy auditors can also use thermography to find gaps in insulation, detect water damage or locate leaky windows and doors.
Equipped with an infrared camera, you'll be able to catch potential problems easily and have an accurate visual representation to guide you as you address them. Although they can involve a hefty initial investment, thermal imagers provide benefits that can have long-lasting effects.
But infrared cameras are complicated devices, and there are a vast number of specifications, features and functions to sift through as you decide on one. In fact, just comparing them on paper can be daunting. After our in-depth analysis of infrared cameras, however, one thing became very clear – these cameras are actually strikingly similar to each other across brands and even across price points.
So what is it then that creates such a vast price range? On our lineup alone, which excludes the highest-end two-handed models, prices fluctuate between $1,000 and $8,500. If they're all so similar, what are you paying for when you buy a more expensive infrared camera?
Although there are subtleties like temperature range, sensitivity and file format to take into account, what you're really paying for are a camera's auxiliary features and its infrared resolution. More than anything else, these two factors will influence the price and capability of your camera.
When it comes to features, there are typically two types of cameras: models that have everything – Wi-Fi, autofocus, touchscreen, etc. – and stripped-down devices that include only the essentials needed to capture infrared information. Those that have auxiliary features are much more expensive than those that do not. Within these two types, there are wide variations in resolution.
Cameras without many features make up the $1000 to $4000 range. Within this group, you'll find a few feature variations, but most price increases are a result of a steady increase in resolution from 80 x 60 to 320 x 240. Cameras with full feature sets, on the other hand, make up the $4000 to $8500 range with incremental resolution increases again playing the most obvious role in each price increase.
For this reason, we don't recommend buying a particular camera simply because it has the highest score. Consider the features carefully and decide what you can live without. If you don't need extra features, save yourself some money and choose something from our bottom five products. For more information, check out our other articles on infrared cameras.
Infrared Cameras: What We Evaluated, What We Found
Early infrared cameras were large, complicated and slow, sometimes taking an hour to produce a single image. Advancements in infrared technology, coupled with new auxiliary features, have made them much more portable, useful and intuitive. Along with sensor characteristics, we evaluated cameras based on the follow categories:
This is the most important factor to consider as you choose an infrared camera. Image quality in standard digital cameras refers to color accuracy, low light performance and lens quality. Infrared images, on the other hand, are all about information.
For this reason, resolution influences image quality ranking more than anything else. The concept is simple: higher-resolution images contain more information and therefore give you a more detailed representation of the thermal landscape. If you're accustomed to the resolution of standard digital cameras, however, you may have to lower your standards.
Modern smartphone cameras commonly produce images in excess of 8 megapixels. In contrast, 0.08 megapixels (320 x 240) is considered top-notch resolution for a handheld infrared camera. In fact, the RESNET (Residential Energy Services Network) standard for the resolution of infrared cameras is only 120 x 120. While there are relatively inexpensive options that offer resolutions like 80 x 60, keep in mind that they may not provide sufficient detail for professional applications.
In order to achieve as much detail as possible, many thermal imaging cameras also come equipped with a standard digital camera. This is typically provided for two reasons: to capture tag photos that afford further context of the scene, and to be used in conjunction with the infrared sensor to produce an image containing the detail of a standard photograph and the thermal information of an infrared image. In this way, you can increase the resolution of your images without having to invest in a higher-resolution infrared sensor.
Another factor we considered when it comes to image quality is focus type. Less expensive models typically use a fixed focus system, meaning the lens is optimized to provide fairly sharp images across the widest distance possible with no need (or ability) to adjust the focus. While this is convenient and relatively inexpensive, models with adjustable focus – whether automatic or manual – afford much more precise focusing and allow you to focus on subjects that would be out of the range of fixed focus models.
Thermal precision refers to an imager's ability to record accurate and nuanced thermal data. When ranking cameras, we base our evaluations on sensitivity, accuracy and temperature range specifications. Later, we'll discuss the emissivity of objects and its effect on thermal accuracy, but first, let's delve into these specifications of infrared cameras.
Sensitivity refers to a camera's ability to distinguish subtle differences in temperature and represent them visually. The best thermal imagers are capable of discerning temperature differences of 0.05 degrees C or less. While increased sensitivity is preferred, even lesser infrared cameras are typically very sensitive, at the very least offering a sensitivity of 0.15 C.
An imager's ability to pinpoint specific temperatures is termed accuracy. Here, as with sensitivity, there isn't much difference among infrared cameras. In fact, the vast majority of cameras claim to have no more than a 2 percent margin of error. While this specification is important to be familiar with, it is shared among most infrared cameras and therefore shouldn't be overly influential in your decision.
We also consider the temperature range of each infrared camera. Typically measured in degrees Celsius, temperature range specifications tell us the exact temperature limits within which a camera can accurately record. Many cameras offer ranges of -20 to 250 degrees C, but some can operate reliably up to 1200 degrees C. Consider your application when comparing infrared cameras. If you don't work with temperature in excess of 250 degrees C, this shouldn't be a major concern.
Lastly, we factor in emissivity. Almost anything you inspect with your thermal imager emits a base level of black body infrared radiation, regardless of temperature. This base level of radiation varies depending on the type of material and is known as emissivity. Because differing materials emit differing levels of radiation, a subject's emissivity can skew your readings if not accounted for. Fortunately, thermal imagers come with emissivity correction settings that you can adjust to compensate. Be sure to consult your user manual to become familiar with the emissivity setting of your chosen device.
Auxiliary features can have a massive impact on your use of infrared cameras in the field. If you're deciding between cameras with similar image quality and thermal precision specifications, features like radiometric video, Wi-Fi connectivity and voice annotations may well become the deciding factor. The following are the features you should look out for in an infrared camera.
Internet connectivity is one of the most useful additional features available for a thermal imager. Wi-Fi–enabled imagers offer Android and Apple applications that allow you to download and email images quickly and easily. This way, clients and co-workers won't be kept waiting until you arrive back at the office.
There are many other features that can be just as useful as Wi-Fi in the field. Practical features like laser pointers and illuminator lamps make it easy to target specific parts and grant additional light for capturing images in darkened areas, while voice and text annotation capabilities let you add notes to your images on the fly. Some cameras can even record or stream radiometric video to measure and record temperature changes in temperature in real time.
Battery Life & Design
With the exception of very expensive two-handed models, most infrared cameras are very similar in design. They generally have a similar grip, button layout and screen (typically a 3-inch or 3.5-inch screen). There are some differences among them, however, that we took into account when ranking infrared cameras.
Battery life, for the most part, doesn’t vary much among thermal imagers. They all tend to last around four hours. Some models, however, come with an additional battery and an external charger. If you expect long days of inspection in the field, you should consider one of these, or at the very least, consider purchasing a spare for your chosen model.
Help & Support
Thermal imagers aren't cheap, and most of us can’t afford to reinvest in tools that wear out prematurely. For this reason, we made sure to carefully evaluate the warranties offered by infrared camera makers. Most manufacturers cover their cameras for at least two years. Typically, this means that the detector and battery as well as parts and craftsmanship are guaranteed against defects for the same period of time.
Some manufacturers, however, split up their warranty and cover different parts of the device separately. While this is slightly more confusing, you usually end up with better coverage. The FLIR E6, for example, comes with a warranty of 10 years for its detector, five for its battery and two for parts and labor.
Because thermal imagery is complex, educational literature is vital to getting the most out of your camera. For this reason, manufacturers often offer extensive manuals, instructions and other information to help educate their users. As you decide on an infrared camera, you should ensure that there is adequate support in this area.
Top Ten Reviews seeks, whenever possible, to evaluate all products and services in hands-on tests that simulate as closely as possible the experiences of a typical consumer. The manufacturers had no input or influence over our evaluation methodology, nor was the methodology provided to any of them in more detail than is available through reading our reviews. Results of our evaluations were not provided to the companies in advance of publication.
What Else Is Important When Selecting an Infrared Camera?
Infrared cameras require periodic calibration to maintain accuracy. As you choose a thermal imager, compare calibration costs as well as the amount of time it might take to send yours in for readjustment. Some manufacturers offer calibration services in their own facilities, while others refer users to third-party calibration services.
Some high-end models come equipped with a touchscreen to facilitate navigation through files and menus. This makes selecting modes or browsing through images much more intuitive than using clunky buttons. These models typically include buttons as well, for those who wear gloves at work.
It's also important to consider file type when looking into infrared cameras. Information contained in the files is more than just visual; there's also data on temperature, emissivity and more. Because of this, thermal images are generally saved as radiometric JPEGs or in a proprietary format that's specific to the camera brand.
Proprietary file types are more difficult to work with because they require special software for viewing. For this reason, you may have to convert the files before sharing them. Radiometric JPEGs, on the other hand, require no conversion and are viewable in any photo viewer. Regardless of the file type, special software is always required to access the thermal data stored within your images.
There are also many accessories to consider when purchasing an infrared camera. External chargers, car chargers and spare batteries are all good things to look into. Additionally, some companies offer interchangeable lenses for their IR cameras that, be it closer or farther away, provide you with an alternate field of view.
Infrared Cameras: Our Verdict and Recommendations
Cameras like the FLIR E60, E50 and Fluke Ti400 are prime examples of high-end infrared cameras. As our three highest ranked products, they boast the highest resolution and the most complete feature sets. Does this make them the best infrared cameras available? Absolutely, but it doesn't necessarily make them the best options for everyone.
Because the quality of construction and materials remains essentially constant across a price range, you may not have to invest in the most expensive product to have a camera that can reliably meet your needs. There are many well-made cameras available that, while offering fewer features and lower resolution, are significantly less expensive, yet still adequate for most applications.
For example, if you want the 320 x 240 resolution of the FLIR E60 but don’t care about auxiliary features like Wi-Fi, a touchscreen or video recording, you could opt for the FLIR E8 instead. Its resolution is the exact same, but it costs half the price of its more fully featured sibling. Conversely, if you need the features but not the resolution, you could go with the FLIR E40. The resolution dips to 160 x 120, but again, it's half the price of the E60.
The same goes for resolution. If you don't need finely detailed images for building professional reports or working with intricate subjects, don't pay for it. Professional inspectors should keep the 120 x 120 RESNET resolution standard in mind, but not all professionals and consumers will need such high resolution.
Choosing an IR camera is not difficult if you know exactly how you intend to use the device. So carefully reflect on your intended application before choosing, and buy the one that makes the most sense for you. For more information on individual benefits, read the full reviews of each camera.