We have come across another problem with the shutter: Not only is it variable when it shouldn’t be – i.e. we have complete frame dropouts and we have a spread in observed counts from sources that are constant – stars at short exposure time excluded here due to scintillation – but we also now have examples of FITS file headers that show the measured to exposure time to be 0.000000000000001s when it is patently not – for instance, the image is fine and shows a well-exposed Moon.

This limits our possibility to use the ‘not simultaneous’ modes of observing – i.e. BBSO and modified BBSO.