Final answer:
To decrease magnification, move the eyepiece farther from the objective lens. Enhancing spatial resolution can be achieved by using a higher numerical aperture, shorter wavelengths, oil immersion techniques, and ensuring high-quality lenses and stable atmospheric conditions.
Step-by-step explanation:
Decreasing magnification would involve moving an eyepiece farther from the objective lens, which generally makes the image appear smaller. However, to increase spatial resolution, and therefore the clarity of an image, one could use a lens with a higher numerical aperture (NA) or use light with a shorter wavelength.
Microscopes, specifically, can improve resolution by using an oil immersion technique, where a drop of oil is placed between the specimen and an oil immersion lens. The oil has a refractive index similar to that of glass which mitigates the scattering of light due to the air gap, thus increasing resolution. Furthermore, using an electron beam, as with an electron microscope, provides a shorter wavelength than visible light and significantly enhances resolution.
Lastly, lens quality and avoiding atmospheric disturbance are essential for maintaining high resolution at great magnifications. A better lens quality will generally result in a clearer image, as will stable atmospheric conditions.