A brief description of optics for hunting and spotting, because what we are really looking for is maximum optical quality and for this, we must first know its components. The aim of the optics is that the binocular instrument, telescope or rifle scope and the human eye form a whole and are perfectly adapted to each other.
Basic principles of optical instruments
We begin by discussing the optical and mechanical principles of optical instruments. The elements that make up an optical instrument are:
- The lens systems
- The prisms.
- The clamping structure.
The lens system consists of:
- The objective lens, oriented towards the object we want to observe.
- The eyepiece lens, oriented towards the eye.
- An intermediate reversing system, so that the objective lens can be viewed in its natural position.
1.1. Lens lens.
The function of the lens is to collect light. The light rays passing through the lens form a precise, small, inverted image that must be corrected before reaching the eye.
1.2 Reversion system.
The reversing system is responsible for reversing the captured image. In binoculars and spotting scopes, the reversing system consists of prisms; porro system and roof prism system. In spotting scopes, it consists of lenses.
1.3 Ocular and diaphragms
The eyepiece acts like a magnifying glass, magnifying the image we wish to observe at greater distances to make it more precise and closer.
The optical system contains several diaphragms that function as "defined apertures. The aperture diaphragms regulate the amount of light and also serve as the basis for the positioning of the lenses. The diaphragms make the image "useful" that if the image is bright and contrasted from edge to edge in the field of view it is because we are looking at a high quality instrument.
1.4 Out Loupe
The bright circle seen in each eyepiece is the exit pupil. The exit pupil of a pair of binoculars is clearly visible when looking into the eyepiece from a distance of about 30cm. In rifle scopes the value is more variable, depending on the magnification and the diameter of the objective lens. The diameter of the exit pupil is a constant mathematical result, relating the objective to the magnification. It does not provide information about the quality of the instrument.
The exit pupil has characteristics that provide information about the quality of the optical instrument; it should be uniform, round, bright and neutral in colour. The appearance of shadows or different tones indicates the use of poor quality prisms.
Now we can choose those binoculars, spotting scopes or spotting scopes that best suit our needs. We are ready for a good hunting or bird watching! If you want you can take a look at our optics products:
- Prismatics
- Telemeters
- Telescopes
- Viewfinders
