BOSMA 7×35 Portable Monocular Telescope with Compass FCM BAK4 Prism Low light Night Vision for Hunting Bird Watching

Embroidery Tiger 7x35 parameters

Series Name:7X35Magnification:7XObj. Diameter:35mmPrism System: RoofFocus System: CenterF.0.V:136m/1000mAngle 7.8°Near Focus 4mExit Pupil 5mmEye Relief 18mm

What is a phase film?

The phase film is a special coating process that is plated on the roof prism. Its function is to effectively correct the phase difference between P light and S light during total reflection, improve color reproduction, increase imaging sharpness, and reduce stray light interference. The telescope's imaging is brighter, clearer, sharper, and more realistic.For roof prisms, the prism splits the light in the optical path into two beams, that is, the light is split into two halves in the prism, passes through the half-silver-coated prism surface and then meets and is combined into one. In the process of continuous reflection, the two beams of light will produce a phase shift phenomenon and a loss of light input, which will cause the image to become blurred. The phase correction coating is precisely to eliminate this phase shift phenomenon to the greatest extent. After the phase correction coating treatment, the image quality can be greatly improved, and the color reproduction can be more realistic and saturated, especially when observing in backlight, or looking at gray tones or When other animals, you will see more colors and details.If the prism is not processed by phase coating, a star halo effect will appear at the light source.

What is a BaK4 prism?

The prism adopts different glass materials, such as BK7 (commonly known as K9) and BAK4. Due to the different properties of glass materials (refractive index, Abbe number, physics, etc.), the resulting optical image difference is also very obvious.The influence of using BaK4 lend on Paul type telescope:In the Paul-type telescope, when observing the incoming halo under a strong light source, you will notice that the halo is cut into a square with the BAK4 prism (except for telescopes with a narrow field of view), and you can see the halo with the BAK4 floor mirror ◆ EK7 will cause part of the loss of light, while the optics brought by BAK4Higher quality.The effect of using BaK4 prism on roof telescope:The use of Bakd prisms in roof-top telescopes can reduce light leakage, increase the height, and make the vision more transparent, sharper and better.

1 Focusing hand wheel: Turn the focusing hand wheel to easily switch the scenery from near and far.2 Light hole: the light entrance of the compass3 Eyecup rotating handwheel: easy to use even with glasses4 Metal LOGO nameplate5 FMC multilayer antireflection film: FMC multilayer broadband antireflection film is adopted, which has high transmittance, high color reproduction, and clear and sharp colors.