Stability and accuracy of the UVBY system

In order to evaluate the transformation errors for stars of various types and classes, the author has simulated observations made with standard and non-standard equipments. Large deviations which cannot be corrected are observed mainly for objects outside the range 0.0 < b-y < 0.4 and in the u filter. The rectangular passbands have many advantages however. They can be very stable and are accurately reproducible. Hence the problem of nontransformable outputs may not exist between such systems. Since many uvby observations are to be collected with such equipments, it could be advantageous to define a new standard "rectangular" uvby system along with the conventional one.