The term optics refers to pretty much everything involving the refraction or concentration of light. For example, a prism refracts white light into a rainbow of color, while a lens concentrates a large amount of light into a smaller space. The surface of water refracts light as it passes through the air/water boundary, so when fishing in clear water the fish you see isn’t exactly where you think it is. This can be proven by dipping a stick into the water and observing how it seems to bend. Conversely, if you have ever used a lens to start a fire by concentrating sunlight into a very small point you understand the concept of focusing light rays.
Binoculars, spotting scopes, and optical rangefinders all utilize both lenses and prisms to magnify images. The same physics apply to rifle scopes. When light enters the outer, or objective lens, the image becomes inverted and somewhat fuzzy due to the rainbow effect of refraction. Prisms located inside the barrel of the device are used to correct this problem. The lens closest to your eye gathers the refracted light, inverting it again so the image you see appears correctly. The amount of magnification provided is indicated by the power rating. As an example, a power rating of 8×40 means the device will magnify objects 8 times, bringing them 8 times closer to the viewer. The second number gives the diameter in millimeters of the objective lens. The size of the objective lens governs how much light is gathered, so larger lenses work better in low-light conditions. However, large objective lenses are heavy and bulky, making the device hard to hold steady. Therefore, spotting scopes with large lenses usually have a tripod stand attached for stability.
Trail cameras are available in a variety of configurations. Some take flash pictures, others can shoot videos, while others can do both. Most are motion-activated and are effective up to about 100 feet. Newer versions are wifi capable, with some possessing the ability to transmit directly to your cell phone. The downside of the cellular trail camera models is the need for a service provider network connection to be available in order for them to transmit images.
While the majority of individuals use their cell phones to take photos, there are lots of people who still enjoy capturing images using cameras. One advantage of cameras is that telephoto lenses can be attached to work like a spotting scope to magnify and bring distant images into sharp relief. Filters can also be added to create different visual effects. Many telephoto lenses offer magnifications of 30x to 40x which is similar to the magnification achieved with a spotting scope.