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 |
| Does the Viper GEN2 650 LRF require zeroing or re-zeroing? | • The platform guarantees point of impact matches the day optic (typically within 3 cm at 100 m) • Optics/rifles may differ slightly across setups |
• Mount once and use one of the three independent alignment profiles (G1, G2, G3) • Save the profile for each optic and switch between them in seconds |
| How do I perform the initial alignment (zeroing) of the clip-on to my day scope? | • Initial offset between day optic point of aim and clip-on point of impact | 1. Mount via M33.5×0.75 thread 2. Select profile (G1/G2/G3) in Settings → Alignment 3. Fire a group at 100 m, measure horizontal (X) and vertical (Y) offset 4. Enter clicks (1 click ≈ 2.6 cm at 100 m) in X/Y menus and Save & Exit |
| Can I use the same Viper on several different rifles or day scopes? | • Multiple rifle/optic combinations require distinct saved alignment settings | • Align once per optic/rifle setup, save to profile G1, G2, or G3, and switch between them without re-shooting groups |
| How does the integrated laser rangefinder and ballistic computer work together? | • Requirement for real-time target distance data and hold-over calculation without manual effort | • Measure target distance with LRF (Single or Scan mode) • Built-in ballistic computer processes distance, ammo profile, and environment to display hold-over on screen |
| How do I set up the ballistic calculator for my ammunition? | • Unconfigured or unselected bullet parameters in the ballistic computer profile | • Navigate to Features → Ballistic Calculator and select profile (A–E) • Input zeroing range, scope height, click value, bullet specs, BC (G1–G7), muzzle velocity, and correction unit • Verify trajectory solution at the range |
| What is the difference between Single and Scan LRF modes? | • Different target tracking needs (static vs moving target / vegetation cover) | • Use Single mode (short press Up) for a single measurement • Use Scan mode (hold button) to continuously update distance on moving targets or through cover |
| What is the measuring range and accuracy of the laser rangefinder? | • Target distance or environmental conditions exceeding LRF operating limit | • Ranging capacity is 5 m to 1200 m (±1 m accuracy, Class 1 laser) • Invalid measurements are indicated on display; check for target distance/reflectivity limits |
| What is the difference between Clip-on mode, Observation mode and Helmet mode? | • Operation in non-optimal viewing or mounting mode | • Select Clip-on mode for day scope mounting (1x fixed zoom, alignment profiles enabled) • Select Observation mode for monocular use (1x/2x/3x/4x zoom) • Select Helmet mode for head-mounts (status icon moved top-right) • Enable Fast Switching in Features menu for quick toggling |
| What is OSD Zoom and why do I need it? | • Day scope optical magnification scaling makes menus/icons too large or cut off | • Press OK + Up button to scale OSD interface across 5 levels (100% → 75% → 60% → 45% → 25%) |
| What is NUC and when should I perform it? | • Sensor non-uniformity causing image degradation over time | • Set to Auto NUC for automatic calibration at regular intervals • Perform Manual NUC by pressing the Down button at any time (no lens cover required) |
| What do the different Scene, Weather and Filter modes do? | • Unoptimized visual contrast for specific environmental or thermal conditions | • Choose Scene: Highlights (detection), Panorama, City, or AI Scene • Choose Weather: Normal / Wet / Hot • Choose Filter: Smooth / Normal / Sharp, combined with 8 color palettes |
| What about image quality in bad weather or dense vegetation? | • Rain, fog, low temperature contrast, or heavy brush blurring thermal targets | • Rely on high thermal sensitivity (NETD <15 mK class) • Enable AI Scene mode and adjust Weather/Filter settings to highlight targets |
| What is Target Lock and how does it help after the shot? | • Animal moves out of FOV after shot in complete darkness | • Enable Target Lock in settings • Recoil detection automatically places a red lock icon and directional arrow pointing to shot position |
| How does Recoil-Activated Video work? | • Missed video recording during sudden shots | • Enable Recoil-Activated Video • Continuous buffer saves ~10s clip surrounding shot upon recoil detection |
| Is there photo and video recording and how much storage is available? | • Low storage space warning or incorrect button shortcuts | • Take snapshot (long press Up) or video (long press Down) • 64 GB internal storage built-in; clear space when capacity warning displays |
| Do I need to calibrate the Leveler and Compass? | • Inaccurate Target Lock / orientation indicators, especially after firmware updates | • Calibrate Leveler on flat surface away from magnetic fields • Calibrate Compass by rotating unit in all directions until 100% complete |
| What is the Video Reticle and when can I use it? | • Video reticle not displaying or Wi-Fi failing to connect | • Enable Video Reticle in Clip-on mode to overlay aiming reticle on recorded video • Note: Enabling Video Reticle temporarily disables Wi-Fi (and vice versa) |
| What battery does it use and how long does it last? | • Power drain, reversed polarity, or battery degradation over time | • Use a single 18650 Li-Ion cell (5+ hours runtime) • Maintain polarity matching markings in battery compartment • Store dry and recharge every 2–3 months during long storage |
| How waterproof and weatherproof is it? | • Exposure to rain, snow, mud, or extreme ambient temperatures | • IP67 magnesium housing provides full dust protection and immersion resistance • Operating temp range is -20°C to +50°C |
| What is the real detection range? | • Difficulty detecting targets at extended ranges or under poor atmospheric contrast | • Maximum human target detection: up to 2100 m (1.80×0.50 m) • Maximum vehicle target detection: up to 4300 m |
| How heavy is it and will it affect my rifle balance? | • Concerns regarding setup weight and balance shift under recoil | • Magnesium body weighs 385 g (without battery), maintaining rigidity and minimal impact on balance |
| What is the startup time and how does Standby work? | • Unintended deep standby or display powering off during operation | • Cold boot reaches full function in <6 seconds • Toggle switch: ON / Standby / OFF • Deep standby triggers automatically if tilt exceeds ±45° sideways or ±60° up/down, or after 5 min inactivity |
| How do I update the firmware? | • Outdated device firmware | • Preferred: Update via NiteVision mobile app • Alternative: Connect to PC via USB-C and manually copy firmware files |
| Where is it made and what support can I expect? | • Maintenance, spare parts, or after-sales warranty service requests | • Designed and manufactured in the EU (Bulgaria) with local warranty and service 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 closed 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 source. |
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 distances. |
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 |
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.
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.
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 Black Hot and White-Hot palettes are the most preferred and easier to use and we recommend them. However, the palette selection is up to individual personal preference. We also recommend the Isotherm palette for easier target detection on distance up to 100m.
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.
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
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#
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.
FOV
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.