The planets come out a lot smaller than the moon and are largest when near or at "opposition"
I have also cropped them down a lot more, so that the effective magnification is much higher than the nominal x240 to x600.
Neptune, Uranus, Mercury are so small as to be hardly worth bothering with in my telescopes.
Currently, Saturn and Mars are very low, as viewed from London, and thus difficult to photograph without lots of turbulence.
The transit of Mercury shot was taken using a professional solar filter over my 720mm telephoto camera lens.