FLIR One Pro vs. Seek Thermal Compact PRO iPhone Thermal Camera Review

Sensor Resolution

Sensor resolution is one of the most important variables for a camera. The sensor resolution defines how much data a sensor captures in a single image. For example, our Canon camera has a 26.2 Megapixel Full-frame CMOS sensor.

We are used to far more detail in our cell phone pictures than what we will get with off-the-shelf iPhone thermal cameras. Similarly high-resolution thermal imaging requires a budget of military proportions. The FLIR camera’s thermal sensor is only 160×120 pixels. In comparison, the Seek thermal sensor is double FLIR’s at 320×240. So, while still small, the Seek sensor is a standout winner.

Winner: Seek

Temperature Sensor Range

The whole point of these thermal cameras is to capture the temperature range within a given view. Of course, every sensor has its limits. Surprisingly, both of these cameras have very similar temperature ranges. The FLIR ONE Pro detects temperatures between -4°F and 752°F. The Seek CompactPRO can detect cooler temperatures, down to -40°F, but only reaches a max temperature of 626°F. Which one is better, then, comes down to our application. Do we need more specificity around cold temperatures or scorching temperatures? Either extreme is not relevant to our needs, so we’ll give the nod to FLIR’s slightly more extensive range but also note that the distinction means little to us.

Winner: FLIR

Field of View

Different lenses allow for a variety of fields of view. At its extreme, a fish-eye lens allows a very wide field of view but at the cost of distorting the image. Straight lines are curved, and objects in the center of the lense are much narrower than they appear. Because of this distortion, it is preferable to achieve the same coverage by shooting with a narrow viewing angle from a greater distance. This method can roughly capture the same subject matter but without the warping. Since our camper is a small, enclosed space, the constraints mean that any photograph we want to take will either cover a limited portion of the interior or capture a distorted perspective with a wide viewing angle.

In this case, we have a choice because both cameras have dramatically different fields of view. The FLIR camera optimizes for narrow spaces with a 55° wide-angle view while Seek prioritized fidelity with a smaller 32° viewing angle. Both approaches have their upsides. The “better” field of view comes down to the subject, not the camera. In our case, the broader field of view is a decided benefit for us, making FLIR our preference.

Winner: FLIR

Power Source

Both the FLIR and Seek cameras are battery-powered, but the location of each battery varies. The FLIR camera has its own internal battery. This is handy because it will not drain the phone battery. As a downside, it must have its own charge in order to work in conjunction with a phone. The FLIR camera takes about one hour to charge and has a battery life of only 45 minutes. If either the phone or camera is out of charge, we cannot take thermal images. So, along with charging our phones, computers, camera batteries, drone batteries, etc, we would also have to keep the FLIR batteries charged. This can be inconvenient for a product that we may want to use intermittently and possibly with little notice. The FLIR’s independent battery is also a concern because once the life span for the battery ends it cannot easily be replaced.

In comparison, the Seek camera powers itself through the phone. As long as the phone has power, so does the camera. With the Seek camera’s relatively low power demands, it can operate on a charged iPhone battery for longer than the FLIR’s 45-minute maximum. Powering from the iPhone makes for a more simple system but it also means that the camera is draining one of our most precious resources: phone battery.

For a power user, who knows they will be using the camera a lot and on a regular schedule, having to power, the FLIR can probably fit into their daily schedule relatively seamlessly. But for a casual user, or one, like us, used to having to travel with backup power packs for our phones, it is preferable only to have to worry about backup solutions for one battery.

Winner: Seek

Video Frame Rate

Both the FLIR and Seek thermal cameras support video capture, but the frame rate is significantly different. We measure the frame rate as frames per second, or hertz (Hz). Generally, the human eye can process 10 to 12 images per second (10-12 Hz) as individual images. The eye perceives anything higher as motion. The Seek CompactPRO only achieves about 15 Hz. But at least that is past the threshold to be viewed as motion, which is not attained by FLIR’s 8.7 Hz frame rate.

This low frame rate is partially understandable: FLIR relies heavily on image processing—using an optical camera to enrich the thermal images. But this results in a problem not only for viewing the video but producing it. There is a slight lag between what is happening and what is appearing on the screen. So a subject—say, an adorable little squirrel—could have wandered out of the shot before it registers on the screen. Both in production and viewing, there is a clear winner for the video feature.

Winner: Seek

Camera Body Dimensions

The comparative size of the FLIR ONE Pro and Seek CompactPRO is a surprise. We assumed—given each camera is performing the same role at a similar price—the FLIR and Seek would be relatively identical sizes. On the contrary, the FLIR camera is 2.7 x 1.3 x 0.6 inches—about the width and thickness of a standard iPhone sticking out an extra inch below. The Seek is almost a quarter the size of the FLIR at 1.75 x 0.8 x 1 inch. Not only does it take up less room, but the Seek is small enough that we don’t have the same worries around bumping and damaging the Seek as we do with the FLIR when it is on our phone.

Winner: Seek

The Optical Camera

As useful as the thermal camera is, it is often helpful to have a standard visual light photograph to orient to the thermal picture. That way, we can easily toggle between the thermal image and the visible light image to identify where the hot spots are. The FLIR camera has two cameras: a thermal camera and a visible light camera installed side-by-side. While it is a very low-quality image, the camera means we have two images from almost the same perspective. Not only does this allow for comparison, but the visible light camera provides for more accurate image processing of the thermal view. But we’ll cover that in the image processing section.

The Seek camera only includes a single thermal sensor in the body. This sensor can still work in conjunction with the phone’s native camera, but there is a parallax effect. The thermal camera is at the bottom of the phone, and the visible light camera is at the top of the phone. So the images are shot from sufficiently different angles that at shorter distances they are not always aligned.

Winner: FLIR

Image Resolution

We already discussed the resolution of the camera sensor. But, between creative software enhancements and superimposed images, the question of the final image resolution is a bit more nuanced than just the sensor resolution. While Seek’s relatively large thermal sensor ensures a more substantial final image (960 x 720 pixels), FLIR does partially make up for its smaller sensor by taking data from the companion optical camera to result in a 640 x 480-pixel image.

Even so, the difference between these dimensions is significant. As a point of comparison, the maximum width of this blog post is 960 pixels. So one of these cameras can produce a single image at a fidelity that can span a blog page while the other cannot. Sizing an image to a blog’s dimensions is a particular use case. But a larger image broadens our options across the board.

Winner: Seek

Aspect Ratio

The aspect ratio defines the height relative to the width of an image. For example, a 1:1 aspect ratio would be a square. In the case of the FLIR and Seek cameras, both automatically default to a 4:3 aspect ratio. This aspect ratio was standard for vacuum tube era televisions and still seen occasionally in applications like Instagram, where boxy images are preferred. But like the advent of HDTV, widescreen monitors, and our smartphone screens, the more conventional aspect ratio is now 16:9.

FLIR only supports the 4:3 aspect ratio. Fortunately, Seek is not quite as limited: we can choose between 4:3 or 16:9 aspect ratio. We would have liked a few more choices, ideally 3:2 like an SLR camera. At the very least, 16:9 is an aspect ratio that can be shared on Youtube without awkward white bars filling the negative space.

Winner: Seek

Watermarks

When the primary function of a device is to render a visual representation of heat, it’s ridiculous to obscure the image with a watermark. (That’s for the photographer, to do) Plenty of free apps will add their watermark to content that we create using their service. But there is some implicit quid pro quo when using a free service to give them a little promotion in return. But we paid for this camera, and it was not cheap. That should be the end of my exchange with FLIR.

The watermark issue seems to be something we only see addressed on a few forums and review comments on Amazon. We don’t see the watermark in the sales images for the FLIR One Pro and there is no mention of a watermark in any product description.

In response to complaints about the watermark in the Amazon review section for the FLIR One Pro, a FLIR technical support representative explained that there is no way to remove the watermark due to “core branding specifications.”

If FLIR was willing to disable the watermark, they could easily update the app to exclude the watermark. It isn’t as if the watermark appears in all image views. Editing modes exclude the watermark. And the FLIR tools app removes the semi-transparent FLIR watermark in the upper left-hand corner but only to replace it with an opaque white watermark on the lower left-hand corner!

There are some workarounds for the watermark. Editing tools can obscure the watermark, but the manual effort is tedious and not a scalable solution. We can crop out the watermark but the image is already small and cropping would remove a significant portion.

It should be noted that the Seek Compact PRO also appends a watermark by default, however it can be easily removed through the app.

Winner: Seek

Image Processing

While hardware is an essential foundation for a thermal camera, image processing is what transforms a collection of data into a visually meaningful scene. While both cameras have customizable color palettes, the FLIR has the ability to enhance the thermal image with data from a photographic image.

Photo Overlay

Here is where FLIR makes up ground. Seek may have higher resolution imaging, but FLIR uses the additional optical camera to blend the visual and thermal images. This way, the software can increase detail in the image and recognize the relationship between a heat signature and the related visual feature. FLIR has branded this MSX enhanced image processing, and it positively contributes to a smoother overall picture. However, in cases of night photography, such as spotting a wild animal, we have to rely on the thermal sensor alone.

Winner: FLIR

Smart Phone Applications

Both cameras are controlled by their respective applications. In FLIR’s case, that’s actually two applications: FLIR One to control the camera and FLIR Tools to edit the images afterward. Meanwhile, the Seek is controlled with the Seek Thermal app.

To be honest, both FLIR and Seek apps are sub-par. Misleading icons on the FLIR app make finding what we want an extended hunt. For example, a symbol in FLIR Tools depicting a series of toggle switches would usually indicate a “settings” dialog. Despite this, the button launches an information panel—better summarized as an “i” icon. Yet, for all my frustration with the FLIR app, the Seek app isn’t any better. Some features are easier to find. Some are more difficult. But, on top of it all, the Seek app has a nasty habit of closing itself when I try to manage specific settings. Fortunately, this isn’t related to core features, so the app is buggy but usable.

It’s hard to pick a favorite when both are so subpar, but FLIR is a little more robust and has a few more editing controls…if we can find them.

Winner: FLIR (but only by a hair)