What corrective action is performed to improve focus when shooting with UV light?

When shooting with UV light, using the infrared (IR) distance adjustment is essential due to the differences in how various wavelengths of light are focused. UV light has a shorter wavelength than visible light, which can lead to focus inaccuracies if a camera is not correctly calibrated for it. The IR distance adjustment helps account for these discrepancies, allowing the photographer to focus properly despite the unique characteristics of UV light.

In contrast, cropping the image would not address any focus issues—it merely alters the composition after the photo is taken. Adjusting the aperture affects exposure and depth of field but does not address focus accuracy specifically related to UV light. Changing the shutter speed only influences the duration that the sensor is exposed to light, without correcting any focusing errors that arise when capturing images under UV light. Thus, the IR distance adjustment is the most effective corrective action for ensuring proper focus in UV photography.