[intotheabyss]

To use the Sun, the focal point would have to be situated about 542 AUs. Certainly not impossible, and the resolution would be quite good, good enough to see surface details of an exoplanet.

[fluoridation]

542 AU is 0.008 LY. Not sure any planets you see there would count as exo.

[wcoenen]

That's where the focal point is, where we can capture the light, not where the exoplanets are.

[fortytwo79]

And could you imagine the bokeh on a portrait?!