Like other manufacturers, Freewell claims that their variable ND filters are very color-accurate. However, VND filters are always critical to color shifts and therefore we should take the marketing announcements with a grain of salt. To truly know, we would have to test how accurate the VND filters are in the real world. Magnetic Filter System K2 – Source: Freewell Futureproof A polarizer is a great filter to help cut glare and enhance colours. By rotating the filter you are able to target different areas of glare in your frame. A polarizing filter is also extremely useful when shooting in an area with lots of highlight since it helps to get a more balanced exposure. The main things to consider when looking at filters are: colour cast, quality, ergonomics and sharpness.

Concerning sharpness and clarity, there is no discernible difference with the Freewell VND filters attached. Images appear just as sharp as you’d expect. Circular polarizers Consequently, we’ll need to judge this filter set on two aspects: the functionality of its magnetic attachment system, and the quality of its VND filters (and filters in general). What Do You Get? J. Matthew Gore I did not encounter the dreaded “X” pattern with these filters. Unfortunately, I did find that many of my wide angle images had dramatically different light across the frame, usually manifesting as a dark bar from the top center to the bottom center of the frame. See the examples below. That being said, it’s near impossible to accidentally bump this filter off. The magnets are quite strong and definitely require a firm hold to come apart. Since this polarizer is magnetic, it’s perfect to rotate in either direction with no worries of the filter unscrewing. Taken with the Freewell Magnetic Circular Polarizer (CPL) The red circle shows where the above climbing photo was taken. A big issue with circular gradient filters is that users can’t adjust where the gradient is in the frame — it’s fixed. With the K2 Island Slot, users can adjust a filter’s height to change its effect on their photos and videos, and even rotate the entire assembly. The K2 also includes an integrated spirit level, or “gradienter tool,” to ensure level gradient filters.The downside to this filter is the colour cast. I personally am not a big fan of the green cast so I’ll have to correct that in post, each time I use this filter. If you do not like to post process your images, this may be a bigger issue to you.

To test color accuracy, I captured a number of RAW images using a Canon EOS R5 in a controlled studio environment. Both the camera and light were set to 5600 kelvin, and the same exposure settings were used at all times (with the exception of shutter speed to match exposure). All images shown below are straight-out-of-camera with no adjustments in post. Quite frankly, K&F Concept’s filters performed much better than expectations. They can easily stand their ground against filters from better-known brands. These results are excellent. In Use Bernard Dery | Light And Matter CPL at 20mm For polarization, do not add a filter to the base ring. If one has been inserted, remove it. Next, flip a “VND” filter over to its “CPL” side, then attach magnetically. CPL filters don’t require alignment, and can rotate a full 360 degrees without hard stops. Looking at the 2-5 stop filter, I can get a range of 2 stops (a little before the 2 stop position on the ring) all the way up to 5 and 1/3 stops (at “5” on the ring), so the filter covers a range greater than the claimed 3 stops.Remove the base ring filter, and there’s now one pane of polarized glass (which is effectively a circular polarizer is).

In colder temps and time restricting locations, being able to just pull off a filter and slap another one on saves a ton of time. It would save your numb hands from trying to thread on and off filters, like you’ve had to do in the past. Generally, a consistent color cast will disappear when you apply auto-white balance in camera or color correction in post. However, color casts may change the relationships between true white and colors similar to the cast and reduce contrast between them. Take this into consideration when shooting. J. Matthew Gore Conclusion and Recommendations Additionally, VNDs are a good value, for you’d have to buy eight solid NDs to match the same range of densities provided by these Freewell VNDs. You may still need at least one or two solid NDs for more challenging environments (as explained earlier), but the Freewell VNDs provide more exposure control for less money and hassle. Colour cast is the hue that the filter gives your image. Kind of like how your sunglasses change the tint of everything you see, filters do the same for our cameras. Colour cast isn’t always a bad thing, however; some colour casts are more pleasing than others. When I tested the PolarPro and Moment VND filters in the past, I found that neither of them were perfectly accurate in terms of their f-stop designations. Both filter brands promised 3 full f-stops (EVs) worth of density, but only provided 2 1/3rd stops.The ND32 did a good job of increasing contrast and clarity — especially in the trees and green foliage. The five-stop reduction in exposure also allowed the camera to shoot at a larger aperture. When five stops aren’t necessary, you may use the CPL from the 2-5 stop VND filter for similar results. User experience All told, Freewell is effectively providing with this system four VNDs (two with diffusion, two without) and two circular polarizers filters for hundreds less than buying each filter type individually. Lens compatibility and vignette performance