Neutral density filters cut visible light, allowing for longer exposures, but also increasing the possibility that infrared light will affect your exposures and introduce noise. Hoya’s SOLAS IRND series of ND filters handles this by also blocking IR wavelengths.
Available in density ranges from 0.3 (1 stop) to 3.0 (10 stops), the series is engineered to provide neutral color throughout the range, meaning your images will have consistent color when switching between filters of different densities. List price: From $48.90. Contact: Hoya, hoyafilterusa.com.