At the same magnification, the larger the objective lens effective diameter, the easier it is to see in dark surroundings. You can choose a model that fits your intended use.
Just as cameras, at the same magnification, the larger the lens diameter, which serves as the entry point of light for the binoculars, the easier it is to see in dark surroundings. Large diameter binoculars with an objective lens effective diameter of 40mm or more are recommended for dim locations such as star observation and birdwatching in early morning hours.
A: At the same magnification, the larger the effective diameter, the brighter the image is.
B: Even at the same effective diameter, IS function is able to reduce shaking to obtain clearer image.
With the same effective diameter, binoculars with an Image Stabilizer function provide a more stable image viewing experience. It also makes binoculars easier and more enjoyable to use under dim light conditions. A larger diameter binoculars model with IS function would provide even clearer images!