Frequently Asked Questions

Got a question about any of our products, how they work, where you can find them, or how you can visit our offices? You can check out our frequently asked questions below, conveniently collated to help you find an answer as quickly as possible. If you don’t see what you are looking for, feel free to contact us with your own query using the form at the bottom of this page.

How is thermal imaging beneficial to birdwatchers?

Thermal imaging devices easily detect the metabolic heat produced by birds, making them perfect for birdwatching, no matter your skill level. Because these devices do not emit any artificial light or infrared illumination, birdwatchers are able to carry out their observations or surveys by night, without the risk of startling any birds or other wildlife. For more information, click here.

Do you drop ship?

TJ Focus is part of Thomas Jacks Ltd — a UK trade-only distributor. We do not send any items to members of the public; therefore, we do not offer drop shipping. If you are a retailer and wish to sell our products to the public, please get in touch at, or call us on 01789 264 100.

Can I come and test out your products if I am interested in purchasing?

Thomas Jacks Ltd are happy to help customers if they wish to test out any of our products. However, please note that an appointment is needed; if you arrive at our offices without an appointment, we will unfortunately not be able to see you.

Can thermal imaging devices see through glass?

No, glass does not let infrared radiation within 8-13ɥm pass through it, therefore no thermal imaging device is capable of seeing through glass.

Can thermal imaging devices see through walls?

A thermal imaging device is only able to detect a body’s surface radiation. It is possible to detect a crack in a wall, or to locate defective thermal insulation, but seeing through walls is not possible.

Can bright sunlight damage a thermal imaging device?

Pointing a thermal imaging device at a powerful source of energy (for example: a unit emitting laser radiation, or the sun) with the lens caps open can have a negative impact on the accuracy of the device.

Can I use a thermal imaging device in extreme temperatures?

Although many modern thermal imaging devices are able to operate effectively in extreme conditions and temperatures, we do not recommend using a device in temperatures exceeding +50°С, as temperatures this high may damage the unit.

Why do I need to calibrate my thermal imaging device?

Calibrating a thermal imaging device allows it to level the background temperature of the microbolometer, eliminating image flaws such as vertical stripes and ghost images (wherein the faint image of an object will remain visible on screen even when it is not being observed). Intervals between the need to calibrate depend on operating time — the longer a thermal imaging device operates in continuous mode, the less frequently a calibration is needed.

Does a thermal imaging device emit anything dangerous?

A thermal imaging device is completely safe. It does not emit anything, only receives and analyses incoming infrared emissions from objects.

What is a refresh frame rate?

A thermal imaging device’s refresh frame rate, measured in Hertz (Hz), tells the user how many times a second the thermal image is refreshed on the unit’s display. A higher refresh rate makes observation of fast moving objects more comfortable. The lowest frame rate is 9Hz. It is important to know that thermal imaging devices with a refresh rate of 30Hz and 50Hz may have export limitations depending on the laws in your region.

Why is image quality not as good in lower temperatures?

Observed objects’ thermal signatures will increase faster at positive temperatures, allowing for higher temperature contrast and an overall greater image quality when compared to that of a thermal imaging device used in colder temperatures. In lower temperatures these objects usually cool down to roughly equal temperatures, leading to lower temperature contrast and thus resulting in the degradation of image quality.

Can I use a night vision device during the day.

Depending on the type of night vision device in question, it should be possible to use it during the day. Digital night vision can be used during the day without causing any damage to the internal elements. Image intensified night vision devices feature a very small hole in the lens cap, allowing the device to be used during the day if this lens cap is closed. However, it is not recommended, as frequent use of an image intensified digital night vision device in this manner will significantly shorten the life of the tube.

Need More Help?

If we haven’t been able to answer your question here, or you are after for more information regarding any of the points discussed above, please feel free to get in touch. Simply fill out the form below with your request, and a member of our support team will be in touch. Alternatively, you can contact us via phone or email.

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