[0.32 lb] I use this filter for multimedia work so I only have to carry one ND filter and can simply rotate the front to change the density. My favorite part is the built in stops. I've used other fader / variable ND filters that just spin and spin like a normal polarizer filter. With this filter you know when the filter is maxed out on either end. Perhaps the person in the previous review with the x-photograph had a faulty filter without proper stops. I also like that this filter has the same front threads allowing me to use the same lens cap. That's not the case with some filters, such as the Genus, which has a larger front. This also means you can't use your lens hoods (at least on the Canon 24-70 and 70-200 L lenses) with the Genus, but you can with the Heliopan. The ability to use my lens hood is invaluable, as I often work in harsh conditions, blocking not only the sun, but also dirt from motocross tracks, paintballs, etc. from my lens. I compared the Heliopan, Singh-Ray, and the Genus Filters for both sharpness and flare blocking ability. Photographing a test target (tripod, shutter release, mirror lockup) I found the Heliopan to be the sharpest, with the Sing-Ray being very close. Both easily out-performed the Genus. The Sing-Ray did the best job at blocking flare, with Heliopan in second, and Genus in last.

[0.32 lb] I use this filter for multimedia work so I only have to carry one ND filter and can simply rotate the front to change the density. My favorite part is the built in stops. I've used other fader / variable ND filters that just spin and spin like a normal polarizer filter. With this filter you know when the filter is maxed out on either end. Perhaps the person in the previous review with the x-photograph had a faulty filter without proper stops. I also like that this filter has the same front threads allowing me to use the same lens cap. That's not the case with some filters, such as the Genus, which has a larger front. This also means you can't use your lens hoods (at least on the Canon 24-70 and 70-200 L lenses) with the Genus, but you can with the Heliopan. The ability to use my lens hood is invaluable, as I often work in harsh conditions, blocking not only the sun, but also dirt from motocross tracks, paintballs, etc. from my lens. I compared the Heliopan, Singh-Ray, and the Genus Filters for both sharpness and flare blocking ability. Photographing a test target (tripod, shutter release, mirror lockup) I found the Heliopan to be the sharpest, with the Sing-Ray being very close. Both easily out-performed the Genus. The Sing-Ray did the best job at blocking flare, with Heliopan in second, and Genus in last.

[Brass] Paired this with the Canon EF 24-70mm f/2.8L II USM Lens. This is made with Zeiss glass and you can really see the difference with other variable ND filters (no color casting versus the rest!) Typically ND filters cause loss of sharpness when but images produced with the heliopan are nice and sharp!

[Brass] Paired this with the Canon EF 24-70mm f/2.8L II USM Lens. This is made with Zeiss glass and you can really see the difference with other variable ND filters (no color casting versus the rest!) Typically ND filters cause loss of sharpness when but images produced with the heliopan are nice and sharp!

[Unthreaded] After shooting w/ decent 3-stop ND filter, I realized the importance of quality filters. The image turned out noticeably unsharp. Not AS important for video work, but I planned to use it for both. So I researched and found a review that said the Heliopan and Singh Ray variable ND's were the sharpest w/ least amount of color shift. I ended up with both a 77mm and 67mm Heliopan. It's expensive, but you get what you pay for. My still images are sharp, and video's look great. Worth the cost. One thing to note, I bought my 77mm a while back, and did not have the stops at the extreme ends of rotation, but was easy to rotate. My 67mm I ordered recently, and I noticed there's friction to rotate it, but it had small screws stops. I wish it was easier to rotate.

[Unthreaded] After shooting w/ decent 3-stop ND filter, I realized the importance of quality filters. The image turned out noticeably unsharp. Not AS important for video work, but I planned to use it for both. So I researched and found a review that said the Heliopan and Singh Ray variable ND's were the sharpest w/ least amount of color shift. I ended up with both a 77mm and 67mm Heliopan. It's expensive, but you get what you pay for. My still images are sharp, and video's look great. Worth the cost. One thing to note, I bought my 77mm a while back, and did not have the stops at the extreme ends of rotation, but was easy to rotate. My 67mm I ordered recently, and I noticed there's friction to rotate it, but it had small screws stops. I wish it was easier to rotate.

[Glass] I love the ability to control exposure time with just a turn of the filter ring given I already choose the f-stop to control DOF. Excellent build quality provides a smooth turning operation and given the brass ring easy on/off of the lens.

[Glass] I love the ability to control exposure time with just a turn of the filter ring given I already choose the f-stop to control DOF. Excellent build quality provides a smooth turning operation and given the brass ring easy on/off of the lens.

[0.32 lb] Pictures were taken with and without the 77mm Vario Neutral Density Filter by Heliopan. The pictures with filter were jaw dropping beautiful! The colors were deeper, brighter and clearer!

[0.32 lb] After renting one of these a few times for video shoots, I decided to bite the bullet and buy one. I use it on my Canon EF 24-70 f/2.8 II lens and that allows me to shoot at wide apertures even in daylight conditions so I can get the selective focus desired. Since it is a variable ND filter you can quickly adjust from direct sun to shade or clouds without having to stop and attach a different filter. Is it the highest quality glass out there? I suspect it's not, but I see no significant loss in image quality and seems well-built for extensive usage. For me, it's a way more desirable option than fumbling with a set of individual ND filters.