Brand comparison
Stellar 4.0 vs Pulsar Thermion 2 vs Nocpix ACE 2: Premium Thermal Scopes Compared
If you're spending premium money on a thermal riflescope, the shortlist usually comes down to HIKMICRO's Stellar 4.0, Nocpix's ACE 2 and Pulsar's Thermion 2 LRF. Choose the Stellar 4.0 if you want a 1,200 m rangefinder and the finest 1280 detail. Choose the Nocpix ACE 2 if you want more eye relief and the widest 1280 view. The Pulsar Thermion 2 suits shooters who put eye relief first, especially on the 60 mm XL60.
We compare the 640 models first, then the high-resolution ones. Every figure comes from each maker's published specifications.
The 640 class: SQ50L, ACE 2 H50R and Thermion 2 XG50
All three put a 12 µm sensor behind a 50 mm lens, so their field of view and per-pixel detail end up almost identical. The differences are in sensitivity, refresh rate, eyepiece and rangefinder.
| Spec | HIKMICRO Stellar 4.0 SQ50L | Nocpix ACE 2 H50R | Pulsar Thermion 2 LRF XG50 |
|---|---|---|---|
| Sensor | 640×512, 12 µm, 50 Hz | 640×512, 12 µm, 60 Hz | 640×480, 12 µm, 50 Hz |
| NETD (as quoted) | <12 mK | ≤12 mK | <40 mK sensor; <20 mK system |
| Lens | 50 mm F1.0 | 50 mm F0.9 | 50 mm F1.0 |
| Field of view | 8.8° × 7.0° | 8.8° × 7.0° | 8.8° horizontal |
| Magnification | 3.5–28× | 3–24× | 3–24× |
| Eye relief | 55 mm | 60 mm | 50 mm |
| Rangefinder | Up to 1,200 m | Built in | Up to 800 m |
| Rated run time | Up to 9.5 h (25 °C) | Up to 8 h | 9 h (22 °C) |
On paper, the Stellar 4.0 SQ50L and the Nocpix ACE 2 H50R lead this class. Both quote NETD of 12 mK or better on a full 640×512 sensor. The H50R adds a slightly faster F0.9 lens, a 60 Hz refresh rate and 60 mm of eye relief. The SQ50L counters with a 1,200 m rangefinder and the longer run-time rating.
The Pulsar XG50 uses a 640×480 sensor, a few rows short of the other two, and its 800 m rangefinder is the shortest here. Pulsar quotes NETD differently, as a sensor figure and a whole-system figure, so it can't be lined up directly against the other two. Treat any NETD comparison across brands with care, since each maker measures under its own conditions; we explain why in how NETD affects the thermal picture.
Field of view and detail across both classes
The diagram below shows how much ground each scope covers at 100 m, with our estimate of the ground each pixel sees. Smaller is finer.
In the 640 class, the three are effectively level on both counts. In the high-resolution class they split: the Nocpix S60R sees the widest scene, the Stellar SX75L sees the finest detail per pixel, and the Pulsar XL60 sits between them with a 1024×768 sensor.
The high-resolution class: SX75L, ACE 2 S60R and Thermion 2 XL60
| Spec | HIKMICRO Stellar 4.0 SX75L | Nocpix ACE 2 S60R | Pulsar Thermion 2 LRF XL60 |
|---|---|---|---|
| Sensor | 1280×1024, 12 µm, 50 Hz | 1280×1024, 12 µm, 30/60 Hz | 1024×768, 12 µm, 50 Hz |
| NETD (as quoted) | <12 mK | ≤12 mK | <35 mK sensor; <20 mK system |
| Lens | 75 mm F1.2 | 60 mm F1.0 | 60 mm |
| Field of view at 100 m | 12.1° (21.2 m) | 14.7° (25.6 m) | 11.7° (20.5 m) |
| Magnification | 3.0–30× | 2–28× | 2.5–20× |
| Eye relief | 55 mm | 60 mm | 65 mm |
| Rangefinder | Up to 1,200 m, in the objective lens | Built in | Up to 800 m |
| Rated run time | Up to 7 h (25 °C) | Up to 8 h | 7 h |
The Stellar SX75L is the detail specialist. Its 75 mm lens gives each pixel about 1.6 cm at 100 m by our estimate, against about 2.0 cm on the S60R and XL60, so animals hold their shape furthest out on the SX75L. Its rangefinder is also rated to 1,200 m, well beyond the XL60's 800 m. Its main drawback in this company is the shortest run-time rating, up to 7 hours at 25 °C. For how far that detail reaches on foxes and pigs, see how far the Stellar 4.0 can identify a fox, pig or deer.
The Nocpix ACE 2 S60R takes in the widest scene, about 25.6 m across at 100 m, which makes it the strongest scanner here. It also offers a 60 Hz mode for following moving animals. The Pulsar XL60 brings the most eye relief, 65 mm, and a 2560×2560 display, but its 1024×768 sensor and 800 m rangefinder trail the other two on paper.
Eye relief and recoil
If you shoot heavier calibres, eye relief matters as much as the picture. The diagram below lines up all four eyepiece figures.
The Stellar 4.0's 55 mm suits most centrefire hunting calibres comfortably. If you shoot something with real kick, the Nocpix's 60 mm or the Pulsar XL60's 65 mm gives you more margin. Our Stellar 4.0 setup guide covers how to set eye relief once the scope is on the rifle.
Which one we'd buy
For most fox and pig shooters buying in the 640 class, we'd start with the Stellar 4.0 SQ50L: full 640×512 sensor, 12 mK sensitivity, a 1,200 m rangefinder and the longest run-time rating of the three. Pick the Nocpix ACE 2 H50R instead if eye relief or a 60 Hz picture matters more to you than rangefinder reach.
In the high-resolution class, choose the Stellar SX75L if identifying animals at long range is the job, the Nocpix S60R if you spend most of your time scanning wide country, and the Pulsar XL60 if you need the most eye relief and can live with 800 m of ranging. The chart below sums it up.
The full Stellar 4.0 line-up is covered in our HIKMICRO Stellar 4.0 review, and the choice between its two sensors in SQ50L vs SX75L. For more options across every budget, see our guide to thermal scopes with rangefinders, from budget to premium.
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Stellar 4.0 SQ50L Stellar 4.0 SX75L Nocpix ACE 2 H50R Nocpix ACE 2 S60R Pulsar Thermion 2 XG50 Pulsar Thermion 2 XL60Premium thermal scope comparison FAQ
What's the difference between the Stellar 4.0 SQ50L and Pulsar Thermion 2 XG50?
The HIKMICRO Stellar 4.0 SQ50L has a 640×512 sensor, a rangefinder rated to 1,200 m and 55 mm of eye relief. The Pulsar Thermion 2 LRF XG50 has a 640×480 sensor, an 800 m rangefinder and 50 mm of eye relief. Both use a 50 mm F1.0 lens with an 8.8° horizontal field of view, so the view is near identical.
Stellar 4.0 SQ50L or Nocpix ACE 2 H50R: which is better?
They're closely matched. Both the HIKMICRO Stellar 4.0 SQ50L and Nocpix ACE 2 H50R use a 640×512 sensor rated at 12 mK or better behind a 50 mm lens. Choose the SQ50L for its 1,200 m rangefinder and longer run-time rating. Choose the H50R for 60 mm of eye relief, a 60 Hz refresh rate and its F0.9 lens.
How far do the Stellar 4.0 and Pulsar Thermion 2 rangefinders reach?
HIKMICRO rates the rangefinder on every Stellar 4.0 model to 1,200 m, and Pulsar rates the Thermion 2 LRF XG50 and XL60 to 800 m. Rated maximums apply to large, reflective targets, so expect shorter readings on a fox or pig in grass, though both cover normal hunting distances comfortably. The Nocpix ACE 2 also has a built-in rangefinder.
Which thermal scope has the most eye relief?
Among these scopes, the Pulsar Thermion 2 LRF XL60 has the most eye relief at 65 mm, followed by the Nocpix ACE 2 series at 60 mm, the HIKMICRO Stellar 4.0 at 55 mm and the Pulsar Thermion 2 LRF XG50 at 50 mm. More eye relief gives your brow more room under recoil, which matters most on heavier calibres.
Which 1280 thermal scope shows the most detail?
By our estimate from the makers' specs, the HIKMICRO Stellar 4.0 SX75L does. Its 75 mm lens means each pixel covers about 1.6 cm at 100 m, against about 2.0 cm for the Nocpix ACE 2 S60R and the 1024×768 Pulsar Thermion 2 LRF XL60. Finer pixels let animals hold their shape further out, which helps with identification at long range.
Which premium thermal scope has the widest field of view?
In the high-resolution class, the Nocpix ACE 2 S60R has the widest view at 14.7°, about 25.6 m across at 100 m. The HIKMICRO Stellar 4.0 SX75L covers 21.2 m and the Pulsar Thermion 2 LRF XL60 20.5 m. In the 640 class, the Stellar 4.0 SQ50L, Nocpix ACE 2 H50R and Pulsar XG50 all sit at about 8.8° horizontally.
Why does Pulsar quote a higher NETD than HIKMICRO and Nocpix?
Pulsar quotes NETD in two ways: a sensor figure, under 40 mK for the Thermion 2 LRF XG50, and a whole-system figure under 20 mK. HIKMICRO and Nocpix quote a single figure of 12 mK or better. Each maker measures under its own conditions, so the numbers aren't directly comparable. Lower NETD helps most on humid, low-contrast nights.
Which of these thermal scopes has the longest battery life?
On the makers' ratings, the HIKMICRO Stellar 4.0 SQ50L leads at up to 9.5 hours at 25 °C, followed by the Pulsar Thermion 2 LRF XG50 at 9 hours and the Nocpix ACE 2 at up to 8 hours. In the high-resolution class, the Stellar SX75L and Pulsar XL60 are rated at 7 hours. Ratings use different test conditions.
Which thermal scope is best for following moving animals?
The Nocpix ACE 2 has the edge on paper, with a 60 Hz mode on both the H50R and S60R. The HIKMICRO Stellar 4.0 and Pulsar Thermion 2 LRF refresh at 50 Hz, which is still smooth for most hunting. A wider field of view also helps keep a running animal in frame, where the Nocpix S60R leads the high-resolution models.
This comparison is based on the published specifications from HIKMICRO, Nocpix and Pulsar; per-pixel figures are our estimates from those specs.