T2S Plus, a thermal imaging camera attachment with macro mode, compared with Hti

I've been using thermal imaging cameras for a long time. My first one was a very basic model, with a resolution of 60x60, which I later replaced with an HT-A2 with a resolution of 320x240. Today I'm reviewing a model with a resolution of 256x192. It might look like a downgrade, but is it really?

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First, I should mention that this is my first thermal imaging camera in an attachment format; the previous two were fully self-contained. Today I'd like to compare the rather expensive HT-A2, which I've already reviewed, with a thermal camera attachment. I'll cover all the advantages and disadvantages of one over the other—and believe me, there are some.

The first thing that surprised me was the size of the package. I remembered the thermal camera being tiny, about the size of a matchbox—or, with its case, maybe a pack of cigarettes—but this was more like a couple of bricks....
Inside was a nice box and some kind of heavy bag. The box said T2S+, so it was mine.


The little box inside is very neat. Given the price of the thermal camera, spending a couple of dollars on the packaging is perfectly reasonable. On the other hand, my smartphone came in a plastic box, so if they want to make it look nice, they certainly can.
There are two versions of the thermal camera, one for Android and one for Apple. Don't mix them up, or you'll have to buy a second phone.

The bag contained a handle and some kind of mysterious mechanism. A note about the handle: I'm not sure what's going on here. The store has two listings, one cheaper and one more expensive, and I suspect the second one comes with a handle while the first doesn't.


The whole kit laid out together. Most of it is paper.


The kit included:
1, 2. A small card congratulating me on buying the thermal camera
3, 4. Instructions, briefly explaining what to turn, where, and why.


1. Mysterious translucent stickers, one large and one small.
2. Two cables—or, more precisely, a Type-C-to-Type-C extension cable with an angled plug, and a MicroUSB-to-Type-C cable.


The thermal camera itself comes packed in a hard case, snugly fitted into a matching recess inside.
Overall, everything here is very secure. There’s a sticker on the bottom of the case warning not to point the thermal camera at the sun or at objects and heat sources with very high temperatures—the results could be disastrous.


The product page lists a few basic specs. Here are a few more:
Sensor resolution — 256 × 192
Frame rate — 25 fps
Focus — adjustable
Field of view — 44.9° + 33.4°
NETD sensitivity — 60 mK
MRTD sensitivity — 500 mK
IR wavelength: 12 µm
Temperature range, two modes: -20...120°C and 120...450°C

Interestingly, the ad lists a range up to 400 degrees, while the app says 450 degrees.

And here I’ll compare some of the specs with my Hti HT-A2.
There are quite a few differences, but the key ones for me (besides resolution) are:
Field of view/focal length: 56° × 42°/4.0 mm
Temperature measurement range: -20°C to 300°C
Thermal imaging frame rate: 9 Hz
IR wavelength: 8–14 µm

You can see that the Hti HT-A2 has a wider temperature range, but it’s all “packed” into a single range, which can sometimes be a deal-breaker.
The field of view is also different; the HT-A2 is a little wider.
But the T2S Plus has a 25 Hz frame rate instead of 9 Hz, and, very importantly, adjustable focus, which we’ll come back to. The HT-A2 has a fixed lens, unfortunately.



It looks compact—actually, “tiny” is more accurate. It measures 26 × 26 × 25 mm, and the body looks like metal or very hard plastic.
The lens is covered by a rubber cap that comes off easily and conveniently. There are ridges on the lens to make adjustment easier.


The product page even has a comparison image with a “well-known brand,” just like those laundry detergent ads :)
Jokes aside, the specs attributed to the “well-known brand” suspiciously resemble those of my Hti HT-A2, even though the picture shows a thermal camera attachment.


And here’s the first comparison: size. The difference is obvious, but don’t rush to conclusions.


One major advantage of the Hti HT-A2 is that it’s completely self-contained. Unlike an attachment, it has:
1. A 3.2-inch display
2. A visible-light camera
3. A light
4. A battery
5. Built-in memory, with 3 GB for photos
6. A body with controls for all of the above, plus a built-in RTC.

If you attach a smartphone to the thermal camera attachment under review, you get all the same features and even a little more—but the size will obviously be different.
Unfortunately, even connecting a smartphone with its regular camera won’t add a feature found on standalone thermal cameras: overlaying the thermal image on the regular camera image. The problem isn’t software-related; it’s hardware-related. The cameras end up too far apart, making it difficult to align their images.



My previous thermal camera was pistol-shaped, which was quite convenient in its own way. The button was right under my finger and took a photo—intuitive and easy to use.
This one came with a handle and a clever mounting bracket. The bracket screws onto the handle, and the handle can also be mounted on a tripod. It all seems convenient, but seriously, what stopped them from putting a button on the handle at the very least—or, better yet, building in a battery?


The bracket is designed to hold both the thermal camera and the smartphone, and it’s exceptionally well made: metal, machined finish, blackened surface, spring-loaded sliding section, and a screw that can’t fall out. Even the screw knobs are metal.
The phone I planned to use with the thermal camera is relatively large, but it still fits with room to spare. There are rubber pads where it’s clamped—nice touch.




The mount for the thermal camera is very similar to the smartphone holder, but it has an interesting protective frame that’s supposed to keep the thermal camera’s connector from being accidentally snapped off. Interesting. It’s made from machined metal too.
Speaking of the connector, I read that this model has fewer contacts, which makes it fit less securely. I can confirm there aren’t many contacts, but it fits snugly in the phone’s port, and the adapter also fits tightly. That said, this could become an issue over time.


The whole assembly is easy to put together, and there’s also an extra joint with a lock to adjust the thermal camera’s angle relative to the smartphone. Overall, it’s fancy and expensive-looking—no complaints. almost.


While putting it together, I noticed a couple of strange, symmetrical holes near the socket on the included extension cable. It looks like there might be a microphone or an LED inside. I tried it and searched for information, but found nothing.


A little more advertising from the product page—and, by the way, it says 400 degrees again, not 450...


It would all be great, if not for a few “buts.”
First, I ran into a problem with the phone. I actually have several, but I had a particular one in mind for the thermal camera—and wouldn't you know it, the app simply wouldn't install on it. No way at all.
You try to download it from the app store and get an error. You download the APK, but the app doesn't detect the thermal camera. It is getting power, but no luck.


I grab my wife's Samsung, install the app without any problems, and launch it just as easily. Okay, my first thought was that maybe Android was too old on my phone—it has version 8.1.0. But no: I grab my main phone, the one I use every day, and it runs Android 6.0.1. The app installs right away. I try the phone I use to shoot videos, which has some version of 7.x, and it installs without a hitch too. So here's what we have:
1. The app won't install or work on the phone I planned to use
2. My main phone has a recessed USB port, so it needs a cable with a longer plug or a regular one that I trim down—but the app works
3. My backup phone runs the app, but it has a MicroUSB port, so I can only use it with the holder.
4. Everything works fine on my wife's phone, and the port is the right kind, but as you can imagine, it's not my phone, so it's inconvenient
5. One of my really old smartphones, probably even running Android 5, predictably wouldn't install the app.

In the end, I decided to use phone number 3, especially since they even included an adapter. I put everything together and tested it. While I was at it, I measured the thermal camera's power consumption: 50–55 mA. And here's another “catch”: if you decide to dedicate a phone to it, remember to unplug it when you're not using it. I didn't know that, and woke up to a nearly dead smartphone. The phone wasn't very charged to begin with, of course, but it hadn't occurred to me that the thermal camera draws power all the time. The only difference is that it uses 55 mA while operating and 50 mA when idle.

So, one more inconvenience—not a major one, of course, but it would have been better to include some kind of button to cut the power. Otherwise, if you use it often, you'll simply wear out the phone's port.


This is what it looks like in your hand


I mounted the smartphone and thermal camera and tried recording. In normal use, with the thermal camera plugged directly into the phone, everything was great. But once I put together the setup with the handle, I realized the thermal camera was upside down.
Yes, the app has options to mirror the image and rotate it 180 degrees, so everything would have been great if not for one small catch.
When you take a photo, everything is fine. But when you record video, the image is rotated on screen while recording, yet the saved file isn't rotated.
Another quirk: if you leave the settings screen—or especially the “gallery”—the app crashes 99% of the time. When you restart it, you have to enable 180-degree rotation again. And yes, the app crashing isn't caused by the phone; it happens on two different devices.
Honestly, I can't remember my Hti HT-A2 ever freezing, not even once. I have no idea what I'd do if it happened—probably hold down the power button—but I've never had a reason to find out.


The simplest solution, of course, is just to turn the thermal camera around. That's what I ended up doing, which solved almost all the problems, but created some new ones.
First, the port cover doesn't protect the connector in this position, because it's on the right and can't be moved to the other side.


Second, well, yes, I think you can guess: in “picture-in-picture” mode, part of the USB adapter is now visible. It's a somewhat contrived scenario, but it can happen.

If anyone from the manufacturer is reading this review:
1. Image rotation should be in the main settings and shouldn't reset when the device is disconnected
2. If that's not possible, the port cover should be reversible, and the plug itself should preferably be angled so it doesn't get in the way of the smartphone camera
3. Add a hardware power switch so you don't have to unplug it from your phone every time.

If you use the thermal camera without the “handle,” there's no need to turn anything around and it's convenient to use. But as I mentioned, one phone has MicroUSB, the app won't install on another, a third has a port that's too recessed, and the fourth—the one that works perfectly—isn't mine.
Tip: before buying, try installing the Xtherm app. If it installs, it will most likely work too.



The Xtherm app downloads without any problems, and you can also find it as an APK file.
After installation, you'll be asked several times for access to files, since the app can save photos and videos. Each time you start it, you'll also be asked for access to the USB device. There's a “do this automatically” checkbox, but it's useless.

There are quite a lot of settings, and what's especially interesting is that you can adjust not only the emissivity coefficient, but also the distance, humidity, and ambient temperature, and apply corrections. With the right settings, this can improve temperature measurement accuracy. In practice, though, I've found that these settings aren't all that critical in most use cases. But if you need the most accurate measurements possible, it's worth exploring this menu.


1. You can also switch between the low (-20...+120) and high (+120...+450) temperature ranges here.
2. Auxiliary settings; it's easier to leave them as they are.
3. Language selection.
4. Device information.


The app's main screen has a button for selecting the color palette. I usually use either the default one or black and white; the others seem less informative to me.
You can also turn off the scale displayed on the right here. Incidentally, it can't be enabled in black-and-white mode.


Additional settings are accessed at the top of the screen.
1. Show temperature at the center / show max/min markers / grid / three modes I don't understand—a dot, diagonal, and square—as well as a delete button that turns off the last three modes.
2. Image controls: brightness / contrast / sharpness enhancement / rotate 180 degrees / mirror image / picture-in-picture.


Brightness and contrast adjustment. I guess someone might need this, but probably not me.


1, 2. There's an aperture icon button in the top right. It forces recalibration. Sometimes the image can become distorted or split into two parts; pressing this button restores it to normal. You can also wait for the thermal camera to do it automatically, but that may take a while.
3, 4. A little lower down there's a lock icon. I don't know what it does. Below that is the color/black-and-white button.


I was interested in the HD feature. When enabled, the frame rate drops sharply, but the image gets sharper. For comparison, the regular mode is on the left and HD is on the right. The difference is easy to see, especially when you look at the two photos one after the other.
I'd guess this mode works best with a tripod, since the correction is clearly done in software.

The screenshots above were taken using the phone's built-in tools. Below are photos as saved by the thermal camera itself.




While preparing this review, I noticed a couple of things. First, the files generated by the app are relatively large: 1440x1080, 2.5 MB, compared with 320x240, 120 KB for the Hti. Second, my old copy of Photoshop refuses to open these files and gives an error.
So I have to convert them to BMP first, then open them in Photoshop. And when I convert the photos in ACDSee, it offers to save them as PNG. It feels like the new thermal camera's JPG files aren't quite JPGs.


These are a couple of photos unrelated to the comparison. I was just curious to see how the new thermal camera “sees” in complete darkness. Sure, ambient light doesn't matter to a thermal camera, but I was curious, and I can say that you can navigate around quite well using it.


Now let's compare them. First, you can see that the screen size on the phone attachment is essentially limited by the capabilities of the phone it's connected to. But you can also see that the standalone unit's image fills the entire screen, while the attachment's usable screen area is also taken up by the control buttons. So the smartphone's screen size isn't the same as the visible image area.


The first thing I use the standalone unit doesn't have is a regular camera. To avoid confusion, when testing batteries, for example, I sometimes take a regular photo and then a thermal one. Also, I sometimes take photos of an instrument's or monitor's screen. The quality is, of course, terrible, but it's more than good enough for "notes".


Now let's compare them. I think you'll be able to tell which is which without labels.
1. The clock and charger side by side
2. The charger on its own.

By the way, since thermal cameras have roughly the same viewing angle, it's fairly easy to compare them, and we can ignore small differences.


1. A kettle on a gas stove
2. The other side of the wall behind which the refrigerator is standing. What's interesting here isn't the heated area itself, but its contrast with the flower in front of it.


The neighboring entrance of my apartment building. In the photos from the attachment, you can clearly make out individual windows in the balcony frame; the Hti is noticeably less sharp.
I used the attachment's regular mode throughout, not HQ. The thing is, although HQ gives a better image, the thermal camera is less convenient to use in that mode. Also, as I mentioned, it seems to be software processing. Comparing in HQ mode would make the Hti look even worse.


These are situations closer to real-world use, since I take photos of houses and walls much less often.
Testing a 1.5 kW load.


And a thermal image of the load as a whole


But the thermal image of the power module is more interesting. Not only can you clearly see the transistors, but even the op-amp pins at a 1.27 mm pitch are visible. The manufacturer claims that macro photography mode lets you inspect components as small as 0201.
Well, even in a "quick shot" of the whole board, you can easily see the op-amp leads. Sure, they're larger than 0201, but this isn't a macro shot either.


Here's a comparison of thermal images of the power supply from a recent review. You can easily pick out individual components on the circuit board, while on the Hti they mostly blend together—even though its sensor has 76.8k pixels versus 49.2k for the attachment, or 1.5 times as many.


For the next experiment, let's look at a board with very small components. As far as I can tell, they're at least 0402, although when I'm soldering them they feel like 0201. In this case, though, it doesn't really matter. This is the board from a DL24 electronic load.


1. View of the microcontroller chip and its surrounding components.
2, 3. This is the maximum magnification. The distance between the board and the lens was around 12–15 mm, though I didn't measure it precisely.


1, 2. The Bluetooth chip and its surrounding components.
3. The power supply section and op-amp; this was the part I was most interested in.


I was interested in the op-amp section because it's fairly easy to heat up one of the resistors by simply shorting the transistor's gate.
The heated resistor is clearly visible.


Someone will surely ask, what about the promised 0201 components? Easy: move the thermal camera farther away from the board so the 0402 components on it appear smaller. And what do you know, they're still perfectly visible, and it's easy to tell exactly what's heating up here.
I'll go further: I'm almost certain I would have been able to spot heating not only in 0201 components, but even in 01005 ones.


The process is much clearer in motion, even though the video has been converted to GIF. In reality, it's even better. By the way, a reminder: all the tests were done in regular mode, not HQ.


Of course, you'll ask: what about the Hti? Well, that's a complete mess. What's more, I bought a couple of lenses for it before the war, and recently one of my regular readers 3D-printed a holder for them.
The lenses were bought with focal lengths of 50.8 mm and 160 mm, and a diameter of 20 mm. I'll say right away that the 160 mm lens seems not to work at all, although in reality it just has almost no effect.
What's more, with the thermal camera under review, you just turn the lens, but here you're stuck with a fixed focal length. In other words, to get a sharp image, you have to adjust the distance between the thermal camera and the object.



This is the best result I got with the board shown in the previous photos.
1. 50.8 mm lens
2. 160 mm lens.
3. Without the lens.

You can see that with the first option, you can make out some details. I even think I could spot this tiny resistor heating up without much trouble, but unfortunately, the image is much worse.
With the second and third options, things are really difficult. Sure, you can identify large objects, but making out anything small is much harder. Of course, you could find a more suitable lens, and I’ve seen people get some pretty decent thermal images online. But it’s inconvenient.


I read that software for Hti works with this thermal camera, so I installed it. Unfortunately, all I got was static, like on an old TV. The image does try to come through, but it looks like it’s buried in heavy interference. The regular camera works perfectly.
There’s PC software too, but I haven’t figured it out yet. As far as I understand, when connected to a PC, the thermal camera shows up as a webcam. But the question is, why would I need that feature at all...


I found a promo code, T2SPLUS50, that takes $50 off. I won’t claim it definitely works, but it seems to work for me. I also don’t know how long it will remain valid.
The question of the handle is still open, since there are two listings: one is cheaper, the other is more expensive, and I suspect the second one comes with a handle while the first doesn’t. Though personally, I don’t think the handle is necessary. I actually found it more convenient without one, but that depends on how you plan to use it...



Conclusions.
First, I won’t sing its praises. I’ll give you an objective account based on using both thermal cameras, as well as the very first one.

So, what’s the advantage of a standalone model, whether it’s an Hti or something similar? Surprisingly, it’s the fact that it’s standalone. It doesn’t matter what software you have on your computer, whether your smartphone battery is charged, or even what connector it has. Yes, being standalone is a major advantage. It’s also convenient to leave it on the desk, ready to pick up, switch on, take a picture, and put back down. Another big advantage is the regular camera, which genuinely helps me.

The thermal camera attachment would have lost, of course, if it weren’t for one BUT. Yes, just one, but a very significant one: image quality. In this case, even with a lower-resolution sensor, the image quality is more than enough to beat that of my standalone thermal camera. Though I should probably say that it’s not just the sensor—or rather, not so much the sensor as the lens with adjustable focal length.

In my view, the thermal camera I’m reviewing has these drawbacks:
1. The power can’t be switched off, so you’ll have to unplug it every time.
2. The 180-degree rotation setting isn’t saved.
3. When rotation is enabled, video is recorded without rotation.
4. The software is generally unstable, but that’s a software issue.

I’ve already covered the advantages, so I won’t repeat them.
So, in short: if you need high image quality and are willing to put up with the shortcomings listed above, I recommend it. I have no complaints about the image quality or the wide range of settings. It’s especially useful for finding problems on circuit boards with very small components. And since the focus is adjustable, you can also check for heat leaks in your home.
If image quality is less important to you than ergonomics, I’d go with a standalone model.

If I were this company, I’d consider making a standalone version. It would definitely raise the price by at least 50%, but I’m almost certain there would be buyers.
I’ve already written about compatibility issues with smartphones. It’s best to install the Xtherm software before buying. If it installs without any problems, the thermal camera will most likely work too.

That’s all from me. I really hope this was useful, and as always, I’ll be happy to answer questions and consider suggestions for tests.