Most Nipon scopes are available with zoom or fixed power eyepieces which can vary from 9x to 78x. Scopes with zoom eyepieces have become popular in recent years especially for many bird watching. It's easier to find your object at low power (which gives a wider field of view) and then zoom in to see more details. This gives you much convenience and saves you trouble changing eyepieces for different magnifications.
However, it should be noted that even though zooms are optically very sharp, they have a relatively narrower field of view as compared with fixed power eyepieces at the same magnification level. Looking through a scope with a fixed wide angle eyepiece (eg. 32mm) is a joy with a bright and wide visual field! If you put two scopes together, one with a 20-60 zoom set at 30x power, the other with a 30x fixed power eyepiece, the difference is striking. You can actually get a wider field of view in the 30x fixed power eyepiece than you will with the zoom eyepiece even when the zoom is set at 20x.
In addition, at the higher end of the zoom power, the image tends to become fuzzy or blurred. This is normal because the amount of light which comes through the objective lens remains the same regardless of the zoom levels. As the image is magnified, the amount of information that contained within the same area of the image is reduced. Therefore, to get a good quality image, either zoom out, or use a fixed power eyepiece.
That's why we have provided a set of fixed power eyepieces as optional accessories in our store, with 16mm, 26mm and 32mm focal lengths. They can add greater values to your scope.