For looking at cells? Here is the feature you want: https://en.wikipedia.org/wiki/Phase-contrast_microscopy https://en.wikipedia.org/wiki/Phase-contrast_microsc

For looking at cells? Here is the feature you want: https://en.wikipedia.org/wiki/Phase-contrast_microscopy https://en.wikipedia.org/wiki/Phase-contrast_microscopy In the "Related methods" section of that article, you can see several things that look like nice modern upgrades that are probably expensive.