To optimize spot separation, the detector should be positioned so that the limit of diffraction from the crystal is just within the plate. Sometimes the crystal may diffract beyond the limits of the experimental setup. It is very important that the detector is not positioned so close to the sample, in an effort to obtain the highest resolution, that the reflections are not adequately resolved. A separation of at least 10 pixels is typically required. A collection strategy should be generated using the strategy option of mosflm .
Strategy can determine both the starting angle and and rotation range for a complete data set.
Also, the testgen option in mosflm should be used to check the number of overlapped reflections, which may be a problem at shorter wavelengths. If overlaps are a problem one may use a smaller rotation range. The low-resolution data sets are collected with the detector further from the sample and the exposure time greatly reduced.