Who is this page for

This page summarizes all frequently asked questions about the Nitehog products. The information provided here is intended to help you troubleshoot your Nitehog devices quickly and easily. If you cannot find an answer to your challenge, please refer to the user manual of your Nitehog product. If that fails to help you, please contact our customer support.


Typical faults and their external signs Possible reasons Possible solutions
When the device is turned on there is no image on the screen. There is no good contact with the battery;
Wrong polarity;
Depleted battery;
Brightness of the screen is set to minimum;
Problem with the battery cap
Display problem
Detector problem
The conditions of the contacts and the batteries is checked and if it is necessary they have to be cleaned;
The batteries have to be replaced with a new ones or recharged;
Adjust the brightness through the menu;
Battery cap replacement
Send the device for factory repair.
The image of the area is weak and foggy Sweating or dirt of the external surfaces of the objective and/or the eyepiece/collimator.
Sweating or dirt of the internal surfaces of the objective and/or the eyepieces;
Clean with napkin or LensPen the external surfaces;
Send the device to the factory for purging with dry nitrogen.
The image is smudged/ negative like image NUC is on external mode /Auto NUC is switch off/
NUC mechanism is stuck
Put the objective cap on and press the N button or switch to internal NUC and press the N button;
If on internal NUC the mechanics do not move when pressing the N button, return the unit to the factory for maintenance.
Switch to Automatic NUC mode
The image is smeared or grainy Wrong weather type or image filter is selected. Try other settings of image sscene types, filter or weather types until you reach the desired image appearance.
The panel buttons do not function Electronics boot failure
Electronics malfunction
Restart the device
Send the device for factory repair
The Pictures saving function is not working. Boot failure
Electronics malfunction
Restart the device
Send the device for factory repair
The Auto NUC is not working. External NUC mode is selected
Shutter is stuck
Switch to internal NUC and press N button.
Send the device for factory repair
The ZOOM is not working. Clip-on mode is selected
Electronics boot failure
Electronics malfunction
Select monocular mode
Restart the device
Send the device for factory repair/td>
The image on the display is blurred and out of focus. Device is not focused on the observed distance
The collimator back lens are dirty
Opto-mechanical malfunction
Focus on the target object
Clean the collimator lens
Send the device for factory repair
When connected to the unit, the Wi-Fi module shows no sign of turning on. Device is not switched ON
Battery is depleted
Wi Fi module malfunction
Port malfunction
Switch on the device
Charge the batteries or change them with charged ones.
Send the device for factory repair.
There are fewer or no de¬tails in the image and there is too much exposure of the object Contrast level is high Decrease Contrast level
Change scene type to Panorama
The scene background is too dark Low Contrast level
Low Brightness level
Increase Contrast level
Increase Brightness level
The image is too dark Low Luminance level
Low Brightness level
Increase display Luminance level
Increase Brightness level
The clip-on goes off when shooting Poor contact with the batteries
Problem with the battery cap
Display problem
Check batteries and battery compartment contacts and clean them, if necessary, with the cleaning cloth. Replace the batteries.
Check that the battery cap is tightly
Return the device for maintenance
There is a shift of the im¬pact point relative to the daily sight scope Incorrectly parallax adjustment
of the daily optic sight
Improper attachment of the clip-on
to the daily optical sight
Ammunition changed
The clip-on needs additional adjustment
Set the parallax correctly of the daily optic sight
Check the attachment of the clip-on to the daily optical sight
Check your ammo
Make additional adjustments with the alignment function
There are defective pixels on the display Concussion in the microbolometer
during shooting or other crashes
Correct defective pixels with the MBPR function in settings
Switch to Automatic BPR mode
There is a ghost effect on the image The device is in calibration mode
of the sensor with an external barrier
(external NUC mode), and access of
light through the lens to the sensor
is not blocked by a hand or cap
during the NUC procedure.
 – Block the access of light through the lens to the sensor by hand or cap during NUC procedure.
– Switch to AUTO NUC mode


Typical faults and their external signs Possible reasons Possible solutions
Thermal imager does
not power on.
Battery completely discharged. Charge the battery
Does not operate
from external power
USB cable damaged.
External power source discharged.
Replace USB cable.
Charge external power source (if necessary).
Image is unclear, with
vertical lines and
uneven background.
Calibration required. Perform image calibration according
to Section 9 ‘Calibration’ of the Instructions
Image is too dark. Low brightness level set. Adjust display brightness.
Colored lines
appeared on display
or image has disappeared.
The device was exposed to static
electricity during operation.
After exposure to static electricity,
the device may either reboot automatically,
or require turning off and on again
Poor image quality /
reduced detection
These problems may occur during
observation in difficult weather
conditions (snow, rain, fog etc.).
Smartphone or tablet
cannot be connected
to the device.
1.Device password has been changed.

2. The device is in an area with a large
number of Wi-Fi networks that
may cause interference.

1.Delete the network and reconnect
using the device password.
2.To ensure stable Wi-Fi operation,
relocate the device to an area with
fewer Wi-Fi networks, or into an
area with none.
Wi-Fi signal nonexistent
or interrupted.
Device is outside the area
of Wi-Fi coverage. There are obstacles
between the device and the receiver
(e.g., concrete walls).
Relocate the device into direct line
of sight of the Wi-Fi signal.
When used in low temperature conditions,<“>
image quality of the surroundings
is worse than in positive
temperature conditions.
In positive temperature conditions,
objects being observed (surroundings and background)
heat up differently because of thermal conductivity,
thereby generating a high temperature contrast.
Accordingly, image quality produced by the
device will be higher.
In low-temperature conditions, objects
being observed (background) do, as a rule,
cool down to roughly the same temperature,
because of which temperature contrast is
substantially reduced and image quality
(detail) is poorer. This is a feature
of thermal imaging devices


Check the sharpening filters settings.

Make sure you have a proper focus on the observed object and the outer optical surfaces are clean. Use the internal NUC function to “refresh” the image.

Depending on the scene and weather conditions the image characteristics may vary. The sophisticated auto gain and brightness algorithm compensates all scene variables, but Nitehog has also manual adjustments of these values as well as weather type function. Take some time to adjust these values in order to improve the image or set the default values.

Mount and alignment

When mounting the device on a day sight/ scope/ camera you must take into account the size of the outer diameter in order to select the correct mounting adapter (Rusan adapter).

17HMR, .223, .243,.270 Win, 7mm Rem, .308Win, .30-06, .300 Win, 9,3×62.

When mounting the device on a day sight/ scope/ camera you must take into account the size of the outer diameter in order to select the correct mounting adapter (Rusan adapter).

Please, refer to the user manual.

All Nitehog clip-on devices are designed and built with precision and maximum deviation from the centre of the day scope up to 3cm in direction, depending on the day scope’s optical axis. However, to match precisely the optical centres of the two devices, you can use the specially dedicated Alignment function.

If the day sight is already zeroed, you need just to proof the accuracy. To do that, please use materials that can easily absorb heat or emit such, or easily cooled down or reflectors, in order to have better contrast on the target while using the thermal device. Such materials are metal plates, heat patches, aluminium foil, bottles with hot water, ice blocks.

No, the average hit point remains the same after attaching/detaching of the clip-on on the rifle scope. If you encounter problems with the precision, please contact your local dealer or Nitehog team.

  1. Caiman X-Core: 12.4×9.3 deg / 21.7×100 m
  2. Chameleon X-Core: 17.7×13.3 deg / 31.1×100 m
  3. Viper A-Core: 11×100 m
  4. Python 19 A-Core: 20.1×100 m

External NUC option is enabled. To clear the image, place the objectives cap in front of the objective and press “N” button or select Internal NUC option from the menu and press “N” button. Please refer to the User Manual section NUC (Non-Uniformity Correction).

Turn off the NIR sharpening filter.

The Auto NUC function is enabled and performed scheduled.

If you happen to lose contrast or image sharpness it is recommended to perform the NUC function to “refresh” the image.

Yes. The external NUC function allows silent NUC by disabling the mechanical shutter. In this mode the NUC algorithm is performed

Actually, the human eye cannot find distinctive difference between these refresh rates. Nitehog Caiman and Chameleon devices are with 50Hz interlaced refresh rate and Viper and Python with 60Hz progressive refresh rates.

By using the USB system cable, Laptop/PC and the Nitehog GUI. Please, refer to the user manual for further information or contact your local vendor.

Changing palettes is performed through the palette submenu in the Image menu. Please, refer to the device user manual.

The SRF (stadiametric rangefinder) is calculating rough distances depending on the object’s size. However, it is pretty accurate and has a proximity difference of 5m @ 100m. A reason for improper measurement could be the selection of wrong object size from the predefined target objects.

The Wi Fi module and the Video connect transmitter is connected to the device through the dedicated fischer connector port on the right side of the device. When connected to power up the Wi Fi module or the video transmitter simply turn ON the unit, since they are powered by the device. Please, note that the battery time might be strongly reduced when using Wi Fi module or the Video transmitter module.

Yes, it is normal the unit to get warmer during prolonged operation or exposed to direct sunlight.

The front lens should be cleaned only with the provided cleaning napkin or LensPen instrument. Do not use strong alcohol or abrasive substances!!!

No, you do not need an additional magnifier. Nitehog thermal imaging front attachments have an observation mode in the functionality, in which the image resolution is scaled to the maximum display resolution, and the user observes a sufficiently large and focused image.


You can check the device firmware by contacting the Nitehog Service Team, or from the device info box in the Menu.

You can check the for newer firmware version of your product by contacting Nitehog Service Team.

If there is a new firmware version available you can check by Nitehog and send your device to the factory or to our service center.

If new firmware update version is available, you can send your device directly to the factory or to our service center for an update.

Gecko 35 Pro app is only available for Android devices. You can download it from HERE.


No, when switched off the device does not use the batteries. However, it is recommended to remove batteries when the device is not used in order to avoid possible battery leakages.

We strongly advice to use only the batteries provided by Nitehog. There are a lot of similar rechargeable batteries on the market but with slightly different size (longer batteries) that can cause damage to contact springs and boards in the battery compartment.

Yes, Caiman and Chameleon devices ca use 2x CR123 Lithium batteries. Please, refer to the user manual for further instructions.

No, batteries should be removed from the device and charged with the charger provided in the delivery set. Please, refer to user manual.

It is possible that you did not place the cap correctly with too much effort and this caused the cap destruction.

Make sure that the cap is positioned correctly, apply moderate effort and turn it in the direction indicated in the user manual.

Send the device for factory repair or contact your local dealer for spare battery cap.


Detector & Optics

Important parameters are divided into two groups:

1. Detector

Detector resolution – refers to the fine detail and clarity of the thermal image and of course the higher resolution the more sensitive elements you have (pixels) this leads also to wider FOV and farther detection distances.

Pitch size

Pitch size – the size of the sensitive elements (pixels) on the FPA. The smaller the elements are the detector is more compact, allows more elements to be placed on the FPA, allowing higher resolution and detailed image.


NETD – is a measure of the sensitivity of a detector of thermal radiation in the infrared terahertz or microwave portions of the electromagnetic spectrum. It is the amount of incident signal temperature that would be needed to match the internal noise of the detector such that the signal-to-noise ratio is equal to one.


2. Optical

Objective’s focal length

The focal length of an optical system is a measure of how strongly the system converges or diverges light. For an optical system in air, it is the distance over which initially collimated rays are brought to a focus. A system with a shorter focal length has greater optical power than one with a long focal length; that is, it bends the rays more sharply, bringing them to a focus in a shorter distance.


F# -In optics, the f-number (sometimes called focal ratio, f-ratio, f-stop) of an optical system is the ratio of the lens’s focal length to the diameter of the entrance pupil.


Field of View –The field of view (also field of vision, abbreviated FOV) is the extent of the observable world that is seen at any given moment. In case of optical instruments or sensors it is a solid angle through which a detector is sensitive to electromagnetic radiation.

The matter of choosing resolution is up to customer’s preference and his needs. The resolution is important to achieve better image performance, including more details that will allow seeing smaller objects on farther distance. The higher resolution will mean also wider field of view. However, another important parameter that goes together with the resolution is the pitch size.

12 µm pitch detector allow the usage of smaller focal length lenses to achieve good distance performance, making that way the device more compact and lightweight. Smaller pitch allows more pixels and their density on the same surface on the focal plane array, therefore better image performance, including more details that will allow seeing smaller objects on farther distance.

Nitehog provide 5* years warranty for its devices.
* For more information the check warranty conditions in our website!

The main difference between these two devices is the objective’s focal length. The bigger focal length the farther distance of detection and recognition can be achieved.

All Nitehog devices are with an IP66 rating, meaning they are water-resistant.

Yes, thermal imaging technology can be used both at night and during the day. For best image performance, adjust the image settings (palettes, contrast, brightness, weather type).

Thermal imaging devices can be used during the day, but direct focused sunlight in the objective can damage the detector. Therefore, it is strongly prohibited to point the objective directly towards the sun.

No, thermal imaging devices work with direct visibility and sometimes can detect heat signature behind very thin obstacles, such as cloth, thin metal and other thin materials that transmit heat. However, seeing through solid walls and other obstacles is not possible.

No, normal glass is a barrier for the infrared waves and reflects them. Therefore, if you look at the window with thermal imager you will see your own reflection.