PX275 - I8 - optical elements in instruments

considering an optical bench, which involves a number of optical elements past aperture, before detection
each active optical element will affect the light paths, and therefore, the image formation at the detector
the result is the convolution of successive convolutions
optic systems modelling is equal to convolutions

F (f * g (x)) = \tilde{f} \tilde{g}

the eventual result is source $* psf (x)$ , which is the point spread function
this function can be very complex due to many optical elements in the light path
the output will be the input $* psf +$ noise
image deconvolving/deconvolution involves working backwards from the observed image to obtain the source
the observed image has finite resolution and signal to noise may contain artefacts and imperfections
therefore, it can be done, but with limitations