Enter the two most important optical characteristics of your telescope here.

Click the button to calculate the eyepieces that you can effectively use with this telescope.

The focal ratio determines how well your telescope gathers light from extended objects. Focal ratios of 5 or less are considered "fast". They gather light well, but require high-end eyepieces for best results. Focal ratios of 8 or greater are considered "slow". They do not gather as much light from faint nebulae, but can be used effectively with economical eyepieces.

This eyepiece will give you the maximum possible magnification with your telescope. You will only be able to use this eyepiece under rare, exceptionally good seeing conditions. It is not an everyday eyepiece.

This eyepiece will give you the maximum reasonable magnification under normal, good seeing conditions. You can expect to use it regularly.

This eyepiece will give you the widest field of view with your telescope, and the brightest rendition of faint DSOs. This is somewhat dependent on the physiology of your eye. It assumes you have normal, young-ish eyes.