The Antoniadi scale for seeing.

Descriptions of seeing conditions are very subjective. In order to try to standardise this area of observing, most planetary and lunar observers use the following seeing scale:


Perfect seeing, without a quiver


Slight quivering of the image with moments of calm lasting several seconds


Moderate seeing with larger air tremors that blur the image


Poor seeing, Constant troublesome undulations of the image


Very bad seeing, hardly stable enough to allow a rough sketch to be made

When observing, the seeing conditions should be noted in the observing log.

Close this window to return to the dictionary