What color filter should be used with a UV light source when photographing fluorescence at a crime scene?

Using a yellow filter when photographing fluorescence with a UV light source is effective because it helps to isolate the specific wavelengths emitted during the fluorescent reaction. UV light excites certain substances in way that causes them to emit visible light at different wavelengths.

The yellow filter allows the emitted fluorescent light to pass through while blocking out some undesired background light or reflections, particularly those in the blue and green spectrum. This enhances the visibility of the fluorescence in the captured image, making it easier for investigators to analyze the scene and any evidence present.

In contrast, other filters such as red, green, or blue may not effectively isolate the desired fluorescent responses, potentially allowing extraneous light to interfere with the clarity of the fluorescence. This can lead to less useful images that do not accurately represent the evidence being documented. Thus, the choice of a yellow filter is key in obtaining high-quality images for forensic analysis.