How to overcome low resolution with a light microscope?

It is not optical resolution which is the problem BUT COLOUR RESOLUTION.Natural light contains all the wavelengths visible to humans and some which human eyes cannot detect but which can give rise to extra colours in the sample by fluorescence. Most artificial light sources do not have the correct colour balance and lack the short wavelengths which cause fluorescence.So the answer in brief is that natural substances can only be seen and photographed properly and with the correct colour balnce by the light of nature.