 options.projector_type = 2</span><span> and then set </span><span style=' font-family: monospace;'>options.projector_type = 1</span><span> and compute backprojection. This, however, is untested and may especially not work when using implementation 1. If you wish to use different projectors, it is recommended to use implementation 3 and set </span><span style=' font-family: monospace;'>options.precompute_lor = false</span><span>.</span></div><div  class = 'S1'><span>The optional PSF deblurring phase can als