SEEK is a relatively new name in thermal imaging, though the people behind it have a long and distinguished track record,
documented elsewhere on this forum.
The first Seek thermal cameras were relatively low resolution dongle types, now known as the Compact series. These offered 206x156 resolution and in my opinion, at least in the earliest types, had quite poor performance. I believe others have mentioned also that there was a thermal gradient issue across the sensor, though I rehomed my Seek Compact XR before using it enough to spot that.
The next product range was the all-in-one Reveal series, which combined a 206x156 resolution sensor with a battery and LCD display in a hand-held package. These were nice to handle but again I believe the resolution and sensitivity were limiting issues. Slow (<9Hz) export versions gave jerky results, as one would expect; the >15Hz US versions were better in that regard.
Further development of the Seek sensors resulted in a remarkably good 320x240 pixel unit. It is offered in various form factors (dongle, OEM module or all-in-one camera as seen above). I’m looking at the all-in-one Seek Reveal Pro here, in the Fast Frame (>15Hz) version. The Fast Frame variant is easy to spot because of the ᖷ
ᖴ 'FF' logo on the top left of the device. The <9Hz version has no such marking but is otherwise outwardly very similar.
The Seek Reveal Pro is an all-in-one high resolution thermal imaging device that fits nicely in the hand. It has something of an air of Star Trek about it. Its sculpted form is thicker at the camera end and the camera is angled slightly downward so it looks straight forward when you hold the screen at a comfortable viewing angle. Ergonomically, it is a superb piece of work. I invited some colleagues to play with it. They have never shown any interest in my various other thermal cameras but this one garnered a great deal of attention. That says a lot about the quality of the design.
Here it is with an old Garmin etrex Legend hand held GPS and a Therm-App thermal camera for comparison.
In order to make the device fit the hand so nicely, Seek decided to orient the camera and screen in portrait mode. I generally abhor ‘vertical video’ but in the case of this device it makes sense to use portrait mode and the format works very well. The display claims to be 320x240 pixels – a 1:1 match with the sensor – but the bezel masks a varying proportion of the screen so I guess there are no more than 220 pixels viewable at the ‘bottom’ of the screen. In practice this has no effect on usability. The following image shows an off-screen photo (left) and a saved file (right). You can see that the bottom of the screen crops the image somewhat, but not enough to be troubling. The moire pattern on the photo is an artefact of the photography and there is no such unevenness on the actual display. That said, the LCD has a slightly visible 'shimmer' to it as it refreshes from bottom to top. It is noticeable if you look for it but not intrusive.
The Seek Reveal Pro comes in two varieties: regular (<9Hz) and Fast Frame (>15Hz) variants. I found a brand new FF version on eBay for under £500 (though the list price is nearer £700). The temptation was just too much!
It arrived after a couple of days, factory sealed with “Subject to US EAR” security seals. It’s worth knowing that I was not asked to sign anything to accept these restrictions (or even notified of them by the seller). The device has similar wording emblazoned on it and also shows it on the boot screen.
The Seek Reveal Pro is incredibly easy to use. You simply press the centre button to power it up, and thermal images appear within 10 seconds. A faint tick can be heard each time the FFC flag moves into position, but unless you're in a silent place you'll have difficulty hearing it. As is normal, FFC happens every few seconds after the camera is switched on but get further and further apart as the camera temperature stabilises. After several minutes there are long intervals between FFC events.
The user interface is just three buttons mounted above the display (or four if you include the torch button on the side). The central button acts as the power switch and also calls up the menu. Palettes are easily selected from the top level by pressing the left button. As with all menus, the left and right buttons scroll down and up, then the centre button selects the highlighted value. It's simple and intuitive (with the possible exception that the different palettes are selected using the ‘filter’ option). All the defaults are sensible.
Perhaps the most important thing is that the software is very snappy, with no lagging. Saving an image by pressing the right hand button is almost instantaneous. This is in stark contrast to other Seek cameras, which can take a couple of seconds to save an image. About 4GB of non-expandable internal memory is provided, which is accessed as a memory stick via the micro USB charging port. PNG (non-radiometric) images are about 225kB and radiometric TIFF images are about 750kB, so that 4GB will store a very large number of images (well over 4,000). I was pleased to discover that my phone is able to access the images by using a simple USB connection.
I am informed that it's vitally important you never try to format the image memory. Deleting images is fine, but the physical memory device inside the camera is partitioned so part is the user-accessible image memory and the remainder is system memory used to store firmware etc. Formatting the memory runs the risk of wiping the firmware and bricking the device. (Thanks Fraser).
The most amazing thing for me was to learn that the Seek Reveal Pro is radiometric. A central reticle can be switched on; the temperature of the spot is shown in centigrade, fahrenheit or kelvin (as per your setup options). Without access to a blackbody source I couldn’t confirm the accuracy but all the readings I’ve seen so far looked pretty realistic. Bravo, Seek!
Battery life is superb. SEEK quote four hours but I managed nearer five. It depends, of course, on how bright you run the screen. I found that setting it to 80% brightness was usually plenty, even outdoors. The 300 lumen flashlight can be set to two different levels. The defaults are something like 90% and 6%. At 90% it is blindingly bright!
Now, the most important thing: image quality. Quite simply, brilliant. I couldn’t believe that I had paid under £500 for such a good picture. There’s virtually no lag; the screen is bright; the FFC flag interrupts are fast and not particularly intrusive; and it’s an absolute joy to use.
Sensitivity is probably in the region of 70mK. That’s not as sensitive as the devices based on Ulis sensors and germanium optics (Therm-App, ThermalExpert etc), but it is certainly more than good enough to visualise small heat leaks in buildings. Once you’re into larger thermal contrast situations the differences between cores tend to become irrelevant anyway. There is very little (if any) fixed pattern noise. The image processing really is very good indeed. The camera copes incredibly well with extremely high contrast scenes that some other cameras have trouble with, for instance it can show cloud detail (effectively ~ -40C) and a hot building (a roof may heat above +40C) in the same image without any difficulty or black- or white-out. (Thanks to Fraser for drawing my attention to this).
I did a side by side comparison of the Seek Reveal Pro, a Therm-App (384x288) with 13mm f/1.0 lens and ThermApp Plus (640x480) with 19mm F/1.1 lens. The Therm-App cameras are definitely a bit more contrasty but (especially in the case of the $3500 Therm-App Pro) we’re not comparing like with like. The Seek has a relatively small chalcogenide glass lens whereas the Therm-Apps were using germanium. I haven’t been able to find out much about the Seek lens but I suspect it’s around f/1.2. It’s fixed focus, unlike the others I mention, but set up nicely so that everything from a foot to infinity are in good-enough focus.
Left to right: Seek Reveal Pro FF (320x240), Therm-App (384x288), Therm-App Pro (640x480), all sized to 320x240 but click for original size. Note how the handles on the filing cabinets can't be seen in the Seek image but are visible in the Therm-App images.
The sensor on the Seek Reveal Pro is made with 12µm pixels, which are some of the smallest on the market. (Therm-App and most other contemporary uncooled microbolometer thermal imagers uses 17µm pixels, whether they are VOX or A-Si). The benefit of smaller pixels include a physically smaller (=cheaper) sensor and a smaller lens because it doesn’t have to create such a large image circle as required by bigger sensors. The downside is that the pixels are only half the area of conventional 17µm sensors, which means there’s less sensitive area. All other things being equal, that means the pixels will be less sensitive than their larger brethren. There’s also the consideration that the pixels are nearing the practical limit for what will actually work in the 7-14µm wavelength range: they are less than one wavelength of light across.
Image resolution is 320x240 pixels, but that may not be the whole story. Particularly when pixels are small in relation to the wavelength, very great care must be taken with the design of the optical system (lens) in order to maximise the spatial resolution. The details are highly technical and Seek don’t release much information about their lens but, all things being equal, I would expect the optical resolution to be less than one would get with a comparable lens on a larger sensor. That said, it’s pretty darned good: Seek clearly have excellent designers who know exactly what they’re doing.
So far so good: everything has been overwhelmingly positive. Are there any downsides? Well, although the pictures flow nice and freely there is no video recording mode nor any way to extract a moving image signal. That could be a deal breaker for some. Otherwise I can’t think of anything else that might be considered a problem. Mike spotted space for a Wi-Fi or Bluetooth module on his teardown video so there may be a new version to come that includes such a facility.
My overall conclusion is that the Seek Reveal Pro Fast Frame is the best budget thermal imaging camera I have ever seen. It weighs next to nothing, is robust, fits in your pocket and gives superb images. I have no hesitation in recommending it.
(Note that these remarks apply only to the Seek Reveal Pro Fast Frame; other variants, such as the Reveal / Reveal XR use a different sensor).
Sample images - click on the thumbnails below. All are as-shot (except the landscape format images, which were turned in an image editor but otherwise not changed).