AbstractA short time spent using the instruments in the GEOmat range under field conditions has shown that the optics are of very high quality, and that the high degree of uniformity has several advantages. The lightness of the instruments and the new features described do however create doubts about the reliability of some new mechanical components, when the instruments are used for prolonged periods under adverse conditions. It will not be until such experience has been gained that it will be possible to say whether the introduction of the new features has been as successful as it deserves to be.