Metal and other reflective samples can be especially difficult to image, as wherever the light source is will be reflected on the sample. With this accessory however, the lighting is coming from 360 degrees around the sample, giving even lighting across the sample. This is especially useful for challenging samples like metal ball bearings.
Ultraviolet lighting is below 380nm outside the visible light spectrum and can be used to increase the image resolution beyond the limit of standard optical microscopes. This can be used to better see cracks in solder. UV light also increases the contrast of certain samples relative to their surroundings, due to the interaction of light with the molecules within the sample itself. One example is protein crystals.
Transmitted Polarized Lighting
Using a filter with the condenser, light can be restricted to a single direction of vibration. This filter can enhance an image by reducing light intensity and glare. This is especially useful with transparent biological samples, as different elements/features of the sample can be observed by changing the direction of the light.