FLIR T420 / T440
As electronics continue down their ever-shrinking path, there is always a leap in size when you least expect it. The FLIR T420 takes the cake on a compact mid-resolution thermal camera, however with small units can come with big problems for bigger members of society like me.
Let me start with a disclaimer: I am a very tall man (6 feet 7 inches) with very big hands. Watching me use a smartphone it quite hilarious, the number of buttons I push when trying to write an email has driven me to madness at the best of times. I must say it’s better than the pre-smartphone era where phones got smaller and smaller, there was a point where I simply couldn’t push just one button on a phone, my wife laughing every time I had to send a text message.
Let’s just say that this definitely puts an interesting spin on operating hand-held equipment, and makes some design features of cameras and touch screens considerably more arduous than the manufacturers of said equipment wanted them to be. When it comes to infrared cameras, I am much more at home with either the gun style cameras or larger units, as the hand grips allow for a larger grip. Some hand-held models have a tendency to squeeze my hand if I use them for longer periods of time, something you will end up doing if you are wandering around large sites imaging.
If you look at the photo to the left, you can see that the T420 hand grip and strap are definitely not designed with someone my size in mind, and I am unable to simply slip my hand in and out of the holder. However if I take the strap off and then adjust it to my hand once I have a comfortable grip on the camera, I am able to hold onto the camera for long periods of operation with no problems. It’s a very lightweight unit, particularly useful for long hours in the field.
After a swift boot up, the screen and image are vibrant, a joy on the eyes compared to lower frequency models. The swivelling camera head with 120° swivel is a fantastic feature of the T420, and has a really nice feel to it. It also allows you a much wider angle of operation than its counterparts, and can be the difference between getting a good image or not in a tight location.
The 320 by 240 pixel detector gives spectacular detail when compared to the 160 by 120 detector cameras, and this is a great representation of what you get for the extra cost. I was able to get good sharp images of the inside of a computer, and the swivelling head made this even easier.
The control for range and span is quite touchy, and took some getting used to. Nudging the joystick in either direction only changes the temperature range or span by 0.1°C at a time, and holding it down will cause it to race wildly once it has moved a single degree. I don’t feel that this fine level control is necessary, and movements of 1°C at a time would be more than enough control over the range and span to get accurate images with little background interference.
The auto-focus is great, and is quite intelligent, much to the same degree that your standard photo camera will operate. The manual focus is driven by a digital scale button, which is a little slow to react but has great control.
Unfortunately, due almost entirely to my overly large hands, I found the touch screen operation of the menu to be quite difficult. The tip of my finger will always cover the button I am trying to push, and there is no way for me to know if I have touched the right button until the next menu comes up. The touch screen operation is a little slow (when compared to your average smartphone), meaning I am often waiting to find out if I have pressed anything at all. Also, the joystick operation is quite small, making it cumbersome for me to operate it freely.
FLIR has a tidy software package for viewing and manipulating images, and many people have become quite accustomed to its simple flow. Manipulating images, pairing images and exporting them to reports is easy and fast, although I would prefer if it automatically paired the visual images with the thermal images. I do run a fairly fast machine and it is worth noting that with any image manipulation software, your machine will have to work quite hard. I wouldn’t recommend having multiple images open at once on your little notebook laptop, you may run into performance issues.
Overall, the T420 is a fantastic unit, capable of capturing some quite stunning imagery. It is a great representation of its price point, and the swivelling head on the camera really makes it stand out for getting into smaller gaps to view difficult systems. However, if you are a large man like myself, it is probably better to stick to the gun-style cameras.
Comparison of a switchboard
Air Infiltration, Missing Insulation
This comparison is relative to building diagnostic imaging.
Small Component Resolution Test
Here is a good comparison of geometric or spatial resolution as we look at small components on PCB boards (in this case a PC motherboard).