Hunter, Gear Expert from United States, OH Public Profile

The Nitehog Viper-35 is the lightest and most compact thermal clip-on I have used with a length of 46mm and a width of 63mm and weight of 254g. Despite its size and weight, its build quality is robust and durable. The Viper is built from one solid piece of magnesium alloy, and its rugged design and construction are impressive. At just under 9 ounces, it adds hardly any weight to any rifle setup, which can be critical on long hunts.
The sensor has a solid 320x240 resolution that pairs with a 1024x768 resolution display. The Viper comes with (2) 18650 Li-Ion batteries. It runs on one battery at a time, and each battery will give the user a full 5 hours of runtime. In my experience, the battery lasted at 4 hours and 40 minutes under the second lowest brightness setting.
The Viper provides crisp and clear imagery with four different display modes ranging from white hot, black hot, red hot, and isotherm. Long range detection is at an impressive 1500 yards. Paired with a good quality riflescope, the Viper is more than capable of making highly accurate shots at 300-400 yards.
Nitehog states that there should be a sub MOA impact shift when mounting from one rifle to another and that claim held true in my experience. The thread pitch on the Viper is M33.5x0.75, which is common with European thermals. Installation is simple and can be achieved in seconds.
The Viper’s settings are simple to access and manipulate. There are 3 buttons along the top of the optic. Press a

The Rix Aurora A3 Thermal Binoculars come with an excellent blend of functionality, ergonomics, and intuitive controls. The sensor's resolution is a respectable 384x288, which pairs very well with the large 2.7" OLED display. Together, the pair result in very clear imagery, with up to 16x magnification. You'll definitely want a longer range to sample when zooming in to the max setting, as everything starts looking like a blur if you're viewing objects within 100 yards. The added soft touch coating, along with the textured design of the plastic inserts on the top of the binoculars make these excellent for use in humid or wet conditions. You have plenty of grip, and a comfortable hold on the surprisingly lightweight unit. The controls are very easy to find while looking through the unit, and the software is very intuitive to use. There are very basic settings and options, including to save and store photos and videos on the included 32GB of storage. You have four different thermal imagery settings for various conditions. These include:
1. White hot spot
2. Black hot spot
3. Red hot spot
4. Full Color hot spot
The battery life has proven to be excellent. With the combination of (8) AA batteries, along with the internal 3800mAh rechargeable one, you are able to get through a full 24-hour runtime. In my testing, I was able to run them for just under 23 hours, but under the 4th brightness setting. Keeping the brightness at level 2 or 1 should allow for the full 24