The selection principles for stereo microscopes mainly include the following aspects:
Resolution requirements: The resolution of stereo microscopes is usually between 120-200 line pairs/mm, depending on the model and configuration. High-end models such as the Zeiss Discovery series are equipped with an APO chromatic aberration correction system and have a resolution of up to 225 line pairs/mm. When choosing, the actual application scenario should be considered. For example, a microscope with high resolution should be selected for occasions where high-precision observation is required.
Magnification and zoom range: The magnification range of stereo microscopes is generally between 6.5x and 225x, and can reach 450x with additional lenses. The zoom ratio is usually 6.3:1 to 20:1. If frequent magnification adjustments or sample manipulations are required, it is more appropriate to choose a microscope with a larger zoom range.
Working distance and depth of field: The working distance is inversely proportional to the resolution, and the working distance is in the range of 92-110 mm under standard configuration. Lower magnifications usually provide greater depth of field and are suitable for observing stereo samples.
Light source and lighting method: The quality of the light source and the lighting method will also affect the actual resolution. The LED light source works best when the color rendering index reaches 90 or above. The ring lighting and segmented control functions have a significant impact on the observation effect.
Ergonomic design: Considering the ergonomic design of the microscope, the eyepiece inclination angle is usually most comfortable at 35 to 45 degrees. Microscopes used for a long time should be equipped with ergonomic accessories to prevent repetitive strain injuries.
Brand and quality: Choose reliable and stable brands, such as Zeiss, Leica, etc., which are guaranteed in terms of optical performance and durability.
