Choose by Magnification
Shaking becomes prominent when the magnifcation goes beyond 8x on general binoculars, making it difficult to be used comfortably or for a long period of time. Using binoculars with an IS function or purchasing an adapter with a tripod when using high-magnification binoculars might help in reducing the image shaking issues.
There are various binoculars models available with different combinations of magnification, objective lenses, and effective diameters to fit in any situation and usage.
Difference between Binoculars Magnification and Camera Zoom
The magnification of binoculars refers to the size of the images appearing the same when the actual distance is reduced to 1/[magnification]. For example, images will appear as same size when the same object is viewed at a distance of 10 m with the naked eye, and at a distance of 100 m when viewed at 10x with binoculars. Remember that the 10x and 15x zoom factor on a camera indicates the zoom factor of the lens’ wide angle base point, making the criteria different from the magnification of binoculars.
Comparison with Camera Lens Focal Length
When a 50mm standard lens (35mm equivalent), which is the closest angle of view to the human eye, is assumed to be 1x, the value multiplied by the magnification of the binoculars is equivalent to the focal length of a 35mm camera lens. For example, a 10x binoculars magnification is equivalent to a 500mm super-telephoto lens. The longer the focal length, the more likely to have camera shake, hence making IS function a more crucial criteria when choosing a binoculars.
Note that these are merely estimates. The figures might differ depending on the type and model of binoculars.