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5 things to know before buying your first thermal optic

how do i decide when buying my first thermal optic

Thermal optics have revolutionised the way we see and interact with the world, especially in fields like hunting, wildlife observation, and security.


These cutting-edge devices allow users to detect heat signatures, even in complete darkness or adverse weather conditions. However, buying your first thermal optic can be a daunting task, given the variety of options available in the market. Thats why we want to find you the best thermal monocular out there for you.


Thermal imaging operates on the principle of detecting and visualizing heat emissions. It doesn't rely on visible light like traditional optics, making it highly effective in low-light conditions or situations where visual obstacles like smoke, fog, or dense vegetation obscure your line of sight.


By understanding this fundamental concept, you'll appreciate the utility of thermal optics in a wide range of applications.


To help you make an informed decision, we've compiled a list of five crucial things to know before buying your first thermal optic:


  1. Decide on Your Purpose:

 view of a thermal scope when hunting

The intended use of your thermal optic is one of the most critical factors in your decision-making process. Different activities require different features and attributes:


  • For Hunting: Hunters often need to identify game in low-light conditions, so they typically opt for thermal scopes. These scopes are designed for precise target acquisition, and while they may have a narrower field of view, they excel in clarity and detection range.


  • For Surveillance: Security professionals and law enforcement personnel require tools that enable night time surveillance. Thermal monoculars are popular among these groups due to their versatility. They provide a wider field of view, making it easier to spot and track subjects in varying scenarios.


  • For Wildlife Observation: Outdoor enthusiasts looking to observe wildlife typically gravitate toward thermal binoculars. These offer a broader field of view and the added benefit of dual thermal and optical zoom capabilities, making them ideal for spotting and observing animals in their natural habitat.


  1. Resolution:

pixel differences for a thermal optic

Resolution is a crucial factor in the performance of a thermal optic. It determines the level of detail you can discern in the thermal images it produces. Higher resolution optics provide clearer and more precise images, which can be especially important for activities like hunting or surveillance.


The resolution is usually measured in pixels, and typical thermal optics offer resolutions ranging from 320x240 pixels to 640x480 pixels. A higher resolution enables you to spot smaller objects at greater distances and distinguish fine details in your thermal imagery.


Resolution is a critical specification in thermal optics for several reasons:

 hikmicro falcon fh25 view

  • Image Clarity: Higher resolution optics provide more detailed and clearer thermal images. This enables you to see finer details and subtle temperature variations in the objects you are observing. In applications like hunting, wildlife observation, or security, clear imagery is crucial for accurate target identification.


  • Target Identification: The ability to identify and distinguish between objects, especially small or closely spaced ones, is heavily reliant on resolution. This is particularly important in security and surveillance applications where identifying individuals or specific objects is essential.


  • Effective Range: Resolution also impacts the effective range at which you can detect and recognize objects. Higher resolution optics allow you to see and identify targets at longer distances compared to lower-resolution counterparts.


  • User Experience: Viewing higher-resolution images is more comfortable and easier on the eyes, leading to reduced eyestrain during prolonged use.



The resolution of a thermal optic is influenced by several factors:

 pixel pitch of a thermal optic

  • Sensor Size: The size of the thermal sensor inside the optic plays a significant role in determining resolution. A larger sensor can accommodate more pixels, resulting in a higher-resolution image.


  • Pixel Pitch: Pixel pitch refers to the spacing between individual pixels on the thermal sensor. Smaller pixel pitch allows more pixels to fit into a given sensor area, increasing resolution. However, smaller pixel pitch can also lead to increased costs and may require more advanced sensor technology.


  1. Detection Range:

detection range of a thermal optic

The detection range of a thermal optic is the maximum distance at which it can identify and capture heat signatures effectively.


This feature is essential for tasks like spotting game in hunting or identifying distant threats in security applications.


Detection ranges vary significantly between models, so it's crucial to select an optic with a detection range that suits your specific needs. Keep in mind that environmental conditions, such as fog or rain, can affect the actual performance of the optic.


Several factors influence the detection range of a thermal optic:

 thermal contrast and temperature for a thermal optic

  • Optical Design: The quality and design of the optic's lens and optics can significantly impact detection range. High-quality lenses and precision optical components can maximize the optic's ability to capture and transmit thermal information.


  • Sensor Sensitivity: The sensitivity of the thermal sensor (often measured in NETD or Noise Equivalent Temperature Difference) is critical. A more sensitive sensor can detect smaller temperature differences, allowing the optic to identify objects at greater distances.


  • Thermal Contrast: The temperature contrast between the target and its background affects detection range. Objects with a significant temperature difference from their surroundings are easier to detect. For example, warm animals in a cold environment or humans against a cooler backdrop are more easily seen.


  • Atmospheric Conditions: Environmental factors such as fog, rain, and humidity can reduce detection range by scattering and attenuating thermal radiation. Understanding how atmospheric conditions affect your specific location is essential.


  • Object Size and Shape: Larger or more distinctive objects are easier to detect at longer distances. Similarly, the shape and orientation of objects can affect their visibility in thermal imaging.


  • Target Emissivity: Emissivity refers to an object's ability to emit thermal radiation. Objects with higher emissivity, like most animals and humans, are easier to detect. In contrast, shiny or reflective surfaces may have lower emissivity and may be more challenging to identify.


  1. Refresh Rate:

refresh rate for a thermal optic

The refresh rate of a thermal optic determines how quickly it updates the displayed thermal image. A higher refresh rate, typically measured in Hertz (Hz), results in smoother, more fluid imagery.


This feature is particularly crucial when tracking fast-moving targets, such as wildlife or intruders, as it minimizes image lag and blurring. Most thermal optics offer refresh rates between 30Hz and 60Hz, with the latter being preferred for applications where rapid target acquisition such as hunting boars, rabbits etc.


Why is Refresh Rate Important?


Refresh rate is a critical factor in the performance of thermal optics and plays a significant role in various applications. Here are some reasons why refresh rate matters:


  • Smoothness of Image: A higher refresh rate leads to a smoother image, reducing image lag and blurring. This is particularly important when you're tracking fast-moving targets, such as wildlife, game, or security threats. A smoother image ensures that you can follow the target's movements without missing crucial details.


  • Enhanced User Experience: A faster refresh rate enhances the overall user experience, making it easier to identify, track, and engage targets. It reduces eye strain and improves your ability to make quick decisions, making it especially valuable in situations where timing is critical.


  • Reduced Motion Sickness: Low refresh rates can cause motion sickness or discomfort when using thermal optics for extended periods. A higher refresh rate helps alleviate these issues by providing more natural and visually comfortable viewing.


  • Better Target Acquisition: In hunting and tactical applications, the ability to quickly acquire and engage targets is vital. A high refresh rate ensures that your target appears without delay, giving you an edge in target identification.


Common Refresh Rates:

 example of refresh rate for a thermal optic

Thermal optics offer different refresh rates, typically ranging from 30Hz to 60Hz. Here's what you can expect from common refresh rates:


  • 30Hz: This is the standard refresh rate found in many thermal optics. It provides a decent level of smoothness and is suitable for a wide range of applications. It's often more affordable compared to higher refresh rate models.


  • 60Hz: A 60Hz refresh rate is considered high-speed and offers exceptionally smooth, fluid imagery. This is particularly important for fast-paced activities, such as shooting sports, tracking fast-moving game, or tactical operations. However, optics with a 60Hz refresh rate tend to be more expensive.



  1. Field of View (FoV)

field of view for a thermal optic

Field of view refers to the area that a thermal optic can capture and display within a single frame. It's typically measured in degrees or the width of the image in meters at a specified distance.


The FoV represents the extent of the scene you can observe through the thermal optic at any given moment.


A well-considered FoV is essential for several reasons:


  • Target Acquisition: In hunting, a wider FoV allows you to spot and identify targets more easily. It reduces the time it takes to locate subjects in the thermal image.


  • Situational Awareness: A broader FoV enhances your overall situational awareness, providing a better understanding of your surroundings. This is particularly valuable in dynamic or high-risk environments.


  • Tracking Moving Targets: For tracking fast-moving objects, a wide FoV is critical. It helps to keep subjects in view and ensures you don't miss important details or changes in the scene.


  • Scouting and Observation: In wildlife observation or search and rescue scenarios, a generous FoV enables you to cover more ground and observe a larger area at once.


How FoV Varies Among Thermal Optics:

field of view examples for a thermal optic 

The field of view can vary significantly between different thermal optics, and it depends on various factors such as the lens configuration, sensor size, and the overall design of the device. Here are the common types of thermal optics and their typical FoV characteristics:


  • Thermal Scopes: These optics are primarily designed for target acquisition and tend to have a narrower FoV. They offer excellent clarity and detection range but may not cover a large area in a single frame.


  • Thermal Monoculars: Handheld and versatile, monoculars typically provide a wider FoV than thermal scopes. They are excellent for scouting, spotting, and general observation tasks.


  • Thermal Binoculars: Designed for observation and surveillance, thermal binoculars offer the broadest FoV of all thermal optics. They provide an expansive view and the flexibility of dual thermal and optical zoom capabilities.


  • Clip-On Thermal Scopes: These can be attached to your existing optical scope, essentially converting it into a thermal imaging device. The FoV is influenced by the characteristics of your optical scope.



When it comes to purchasing a thermal optic, it's essential to focus on the key features that will best suit your intended application. These features will significantly impact your experience and the effectiveness of your thermal optic.


By understanding the importance of these features and carefully assessing your requirements, you can make an informed decision and choose the right thermal optic that meets your needs, whether you're hunting, observing wildlife, or ensuring security and safety.


 Remember that the right thermal optic can enhance your capabilities in low-light or challenging conditions, providing you with a valuable advantage in your chosen activities.

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