The choice of the instrument for research is crucial. It is included/understood well that the size of the mirror is determining as for the depth of research. The study of objects with great shifts towards the red and thus with weak flux thus supposes to use large telescopes.
Size of the field, i.e. the surface of sky seen by the telescope, is also of primary importance. Research is made randomly and numbers it objects depends on the volume of universe covered at the time of the observations. The use of telescopes with large fields thus makes it possible to increase the chances of discoveries.
Let us see more precisely how these parameters influence the effectiveness of detection of supernovæ.
The signal on noise