Introduction BS-2074 series microscopes are high level microscopes which are specially designed for college education, medical and laboratory research. With excellent optical quality, large field of view, excellent objective lens performance, clear and reliable imaging. Ergonomically designed to provide better comfort and experience, focus on the user's operating habits, and constantly optimize the details. The modular design allows for various viewing modes such as brightfield, darkfield, phase contrast, fluorescence and simple polarizing. The intelligent design makes the microscope teaching more flexible and the teaching effect is better. Low maintenance costs and environmentally friendly. Features 1. Excellent Optical Design. (1) NIS infinite Optical System. NIS infinite plan objectives can provide high contrast and very flat image up to FN22mm, the system always brings you sharp, high resolution and high signal to noise ratio imaging. (2) 22mm Wide Field of View. The microscopes achieve the wide field of 22mm view with 10× eyepieces. The eyepiece adopts a flat field distortion-free design to prevent the edge of the field from being imaginary and stray light. (3) Various Observation methods. Besides bright field observation, dark field, phase contrast, fluorescent and simple polarizing observation methods are optional. (4) Multifunctional Universal Condenser. BS-2074 series microscopes adopt a universal condenser for bright field, dark field and phase contrast. The observation methods could be quickly switched by changing the dark field and phase contrast slider. The phase contrast and bright field slider is universal for 4×-100× objectives, simple and fast to use. The aperture diaphragm of the condenser is easily set to get exact value of diaphragm to correspond with different objectives. (5) LED EPI-Fluorescent Illumination. The LED EPI-Fluorescent Illumination is safe and convenient. There is no need to warm up or cool down, and also no need to align the bulb. The life time of LED bulb is up to 5000 hours. There are two filters position available and switch is fast and easy. 2. Infinite Plan Objectives. The BS-2074 series microscopes have been fully optimized for various of microscopic applications, especially for beginners and the users with long time operation. The objectives provide high quality images and are easy to use. 1) Plan Objective. With infinite plan objective, clear and flat image is over the entire field of view, image reproduction is better. (2) 100× Water-immersion Objective. Ordinary 100× oil-immersion objective needs to use cedar oil as the observation medium. After use, it needs to be cleaned with ether alcohol or xylene, which is easy to cause air pollution and improper cleaning. The water-immersion objective uses water as the medium, it is easy to clean, it also reduces the damage to the user's health and environmental pollution. (3) 40× LWD Objective. The working distance of 40× objective can be up to 1.5mm, avoiding the contamination from residual immersion oil or water when converted from 100× to 40× objective. 3. This is an unbounded microscope. Multifunctional digital head is optional, the user does not have to be confined in front of the microscope. Instead, it can be used for mobile microscope teaching and outdoor field observation through mobile terminals and external mobile power. The objective, eyepiece and observation tube have been effectively anti-mold treated, so it can ensure a consistently clear image and extend the life of the microscope, even when working in hot and humid environments. (1) Multifunctional Digital Head. The built-in camera, supporting Android, IOS, Windows operating system, wired a