November 18, 2025 Primal Hunter

What Is a Good Thermal Scope?

Choosing the right thermal scope isn’t about grabbing the priciest one on the shelf, it’s about matching it to how and where you hunt.

Chasing foxes or pigs out on wide open plains? Or getting in tight through thick bush? Just knocking over rabbits inside 100m, or looking to spot pigs out past 300m?

All of these things matter when picking the right thermal. Go too low end and you’ll struggle with range and clarity. Go too high end and you could spend thousands more than you actually need to.

Let's go through the key things to keep in mind when choosing a thermal scope.

1. Image Quality

Image quality is the backbone of any good thermal scope. A few key specs make all the difference:

Thermal resolution — this is the number of pixels in the sensor. More pixels = clearer detail when spotting game.

NETD (Noise Equivalent Temperature Difference) — this measures how sensitive the scope is to tiny temperature differences. A lower NETD means the scope can pick up finer detail, even in fog, cold mornings, or thick bush.

Pixel pitch — this is the size of each sensor pixel. Smaller pixels usually mean sharper images and better clarity at distance.

Good image processing and enhancement tech also help you pick animals out of background clutter - especially in scrub, long grass, or dense bush.

Below is a general guide to the common specs you’ll see on thermal scopes

2. Detection and Identification Range

Detection and identification range tell you two important things:

How far you can pick up heat signatures
How far you can positively ID what you’re looking at — whether it’s a pig, fox, roo, or just a warm rock.

A longer range doesn’t automatically mean a better scope. What matters is how you hunt. If most of your shots are inside 100–150m, you don’t need a scope rated for 2km detection.

But if you’re chasing pigs out on big open paddocks, a longer detection range can be a real advantage.

Remember, the advertised ranges are usually tested in perfect conditions. In the real world, weather, humidity, fog, and terrain (like long grass, hills, or scrub) can all reduce how far you can see or ID a target.

Choose a scope that matches your actual hunting conditions, not just the biggest number on the box.

3. Field of View (FOV) and Magnification

Having the proper Field of View (FOV) and magnification is crucial in ensuring a comfortable viewing experience.

A wider FOV with low base magnification is perfect for close range or dense bush. It lets you see more of what’s in front of you and makes it easier to track moving animals at short distances.

A narrower FOV with higher magnification is better for long range hunting. As you’re scanning from a long distance it is easy to cover a lot of ground, therefore a wider FOV may not be so crucial in this situation. In fact, a narrower FOV and higher magnification can help in these instances for faster target acquisition and identification.

Choosing the right balance depends on where you hunt and how far you typically shoot - the below FOV comparison illustrates this perfectly.

Spotting game using the Guide TD Gen 3 Thermal Monoculars

4. Laser Rangefinder

A built in laser rangefinder makes judging distances quicker and more accurate.

It’s especially handy for long range hunters. If you hunt new or unfamiliar terrain, it can save time and help with more precise shots.

But if you rarely need a rangefinder, you can often save hundreds of dollars by choosing a thermal scope without this feature.

5. FAQs

Now that you’ve got a better handle on choosing the right thermal scope for your hunting needs, let’s wrap things up with the top three questions we get from Aussie hunters.

These should help clear up some of the common concerns and give you the confidence to make an informed decision.

Q1: Which scope will let me ID targets at X distance?

Answer: As a rule of thumb, the recognition range for medium game (like feral pigs) is about half the detection range listed in the specs.

The identification range is roughly half of that again. Keep in mind, weather, terrain, and image processing all affect real-world performance.

Q2: Can I use one thermal scope on multiple rifles? Do I need to re-zero each time?

Answer: Yes! Most quality scopes let you save up to five ballistic profiles for different rifles.

With a quick release mount, you can swap rifles without re-zeroing - just make sure you mark/mount it in the same spot each time on your picatinny rail.

Q3: How do thermal scopes mount?

Answer: Most use a standard 30mm tube with rings or proprietary mounts that attach directly to a picatinny rail.

Hunter using Guide TU635L 3.0 Thermal Scope

Final Thoughts

A good thermal scope isn’t ‘one size fits all’ - it’s about matching the scope’s features to your specific hunting style and needs.

👉 If you’d like to browse our full thermal range, check out our collection here.

👉 Still unsure which scope is right for you? Give us a call on (03) 7071 0777 and we’ll help you find the perfect fit for your hunts.

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