K&F CONCEPT 37MM, True Color Variable ND2~ND400, ultra-thin adjustable filter, optical glass

The K&F Concept 37mm and 40.5mm True Color Variable ND (Fader ND) Filters allow precise control over light entering your camera lens. These ultra-thin optical glass filters reduce exposure by 1 to 8 stops without affecting color, making them ideal for long-exposure photography, cinematic video, and creative depth-of-field control.

Take complete control of exposure with the K&F Concept Variable ND (Fader ND) Filters, available in 37mm and 40.5mm sizes. Designed for photographers and videographers, these neutral density filters reduce light without altering the color balance of your scene. With an adjustable range from ND2 to ND400, you can smoothly control exposure from 1 to 8 stops or more, allowing longer shutter speeds or wider apertures to achieve creative effects such as motion blur in waterfalls, flowing clouds, or shallow depth-of-field. Constructed from premium optical glass and featuring an ultra-thin frame, these filters prevent vignetting even on wide-angle lenses. Unlike post-processing software, these filters physically control light at the lens, giving a natural, professional result right in-camera. The front element rotates smoothly for precise adjustment, functioning like a polarizer to regulate incoming light efficiently. Essential for outdoor, landscape, and cinematic shooting, these filters ensure accurate color rendering while providing maximum creative control.

Key Features:

• Adjustable Variable ND (Fader ND) filter
• Smooth light reduction from ND2 to ND400 (1–8+ stops)
• Preserves true color without distortion
• Ideal for long exposures and shallow depth-of-field
• Ultra-thin optical glass to prevent vignetting
• Works as a polarizer with rotating front element
• Enables natural in-camera control of light, unlike post-processing
• Perfect for photography and videography