This 3-stop, 100 x 150mm X-PRO Square Reverse Graduated ND Filter with Frame from K&F Concept is made for the X-Pro Square Filter Holder System. This reverse graduated filter allows a selective area of density to be added to an image, making it an essential tool for enhancing landscape images. This filter's reversed soft edge tapers off to darken the selective area of the image by three stops, and it is well suited to darkening sunrises and sunsets for more saturated, impactful images.

Made of high-quality optical glass, this 100 x 150mm, 2mm thick filter features 28 layers of multicoating for optimal light transmission without adding any color cast. The coating also protects the filter from water, oil, minor scratches, and abrasions. It features a protective frame with large tabs that make it easy to install and remove from the X-Pro filter holder system.

0.9 Optical Density    28-Layer Multicoating    2mm Thick Optical Glass Construction    Moisture-Resistant Coating    Scratch-Resistant Coating    Reduce Exposure in Selective Areas    Allows Long Shutter Speed, Wide Aperture    Leather Case

• Fits the K&F Concept X-PRO Filter Holder System
• Plastic filter frame has a tab for easy handling
• High-quality AGC optical glass
• Nano-filter multi-coating reduces lens flare and ghosting for high light transmittance with no color cast
• 28-layer coating is scratch resistant, waterproof, oilproof, dustproof, and suitable for harsh environments and locations

Related Questions and Answers

Q: 1. Are these stackable? I'm looking for a ND+CPL

A: The K&F Concept ND & CPL Filter Kit for DJI Avata (3-Pack) are not stackable.

Q: 2. Inside dimensions? Also will use this for a butterfly set-up. Any structural problems with a butterfly using this updated corner? Using 1 square aluminum tube from hardware outlet.

A: None at all

Q: 3. What type of lens cap to use for the B+W 82mm XS-Pro Digital ND Vario MRC nano Filter ?

A: I am using the Slip-over cover which came with the Filter, however it is very annoying, since it falls off all the time. Please let me know if there is a suitable cover, which is held secure.

Q: 4. When stopped to the highest setting (5 stops) does the image degrade (sharpness, cross hatching)?

A: I've shot extensively with the 95mm, 72mm, & 67mm versions. You don't get any cross-hatching, but a definite vignette in the corners toward the 5 stop range when shooting photos. Video is not an issue as it crops to 16:9. Other than than, negligible colour cast & no sharpness issues.

Q: 5. Can I use a this filter for a Canon 24-105mm and Sigma 18-35mm lens?

A: Yes, but you need one more part to make it fit. You'll need what's called a step-up ring. Your Canon lens is a 77mm filter thread size and you need a step-up ring (super cheap to buy) that spans the difference (a 77mm to 82mm ring). Same for Sigma - need to find a 72-82mm step-up ring or you may have to buy two, a 72-77mm and a 77-82mm. You can shop for them here.

Q: 6. How can we clean the inside of the filter?

A: I must admit in a career of photography never needing to clean the inside of a rotating Polarizer. If for some really reason you actually had to clean the inside, that would be a task for a professional camera technician. No user serviceable parts are here.

Q: 7. Can this filter be used on wide angle lenses for example Sigma 10-20mm? I have tried cheaper alternatives with extremely poor results. Uneven darkening and camera (Pentax K-7) metering failing resulting in gross underexposure.

A: I've tried only 2 variable ND filters: this B+W one and a similar one by Genustech. Non-variable ND filters have fewer problems. From what I've read, most of the variable ND's, like the Genustech, have the shortcomings you describe. This B+W does not. It is consistent in how it transmits light across the whole filter without the usual cross artifact that darkens the image unevenly. I use this filter mainly for video with large sensor cameras; my only qualm with the filter is that it doesn't get dark enough for very bright scenes and that's partly due to my lowest ISO rating being 400. So I have to stop down the lens anyway, just not as much, but more than I'd like to. I can't vouch for no vignetting on a 10mm super wide lens. I get no vignetting at 17mm focal length on my 17-55mm Nikon zoom. B+W's engineering and build quality is usually superior to the rest.

Q: 8. Can I use this on my Nikon wide-angle lens 10-24mm without vignette?

A: Most likely, no. The rim on this filter being the variable midel, is much wider than a standard ND would be. You definitely need to find a fixed stop ND for a wide angle. Even with that, you may still have slight vignetting at the 10mm end.

Q: 9. I have a UV protective filter, Can i use it in addition to a Polarize filter? Stack all 3?

A: It's typically advised you don't stack filters due to diminishing transmission and risk of unwanted glare/artifacts/color-shifting/cross-polarization.

Q: 10. There's only one knob. Does that mean the other 1" square tube is permanently attached to the corner?

A: Both tubes are removable. One is secured with a t-handle and the other is secured with a set screw. This is designed to allow for the frames to be stored easily and half built, also so the t-handles don't interfere with one another.