I was asked recently to do a quick review of the pre-production magnetic circular filter set from Kase Filters. My set included a slim-line adapter (the set I was supplied with was a 77mm filter set and adapter), a circular polariser, a 10 Stop ND filter and a hard 3 graduated filter (just for demonstration purposes (not tested) in a nice Kase leather pouch.
I have tested the neutrality of the Kase filtration before (3, 6 and 10 stops), but I, and also a few fellow photographers, have had a recent play with the CPL and NDs, whilst out an about. The CPL is comparable to the screw-in 82mm G-CPL I tested last year (It’s the same filtration used in the Graduated Filter Wolverine Series and has been rated by, On Landscape Magazine, as on of the most neutral graduated filter system they have tested).
Whilst the Screw-in G-CPL gave about 2.5 stops of light filtration, this mag version has slightly less, about 1.5 to 2 stops, using in-camera exposure metering. I did find, however that you still see that large dark blue wedge in the sky, at wide angle, you would expect with using a CPL, meaning it’s doing what it is supposed to do. There are few instances I think where you need to use a CPL on it maximum setting, perhaps increasing clarity in haze or perhaps cutting reflections, where some of the very thick 105mm CPLs may give a bit more filtration. But in most situations, with what I capture anyway, this mag CPL I felt would be quite adequate.
The filters are much thinner than a standard circular filter, use toughened glass (NDs 0.7mm and the CPL 1.1mm thick) and very light (see table). They each have a built in magnetised rim and thus can be stacked (see above sequence). I was concerned, that when stacked, these would vignette at wide angle (knowing that my Kase screw-in filters (ND and G-CPL) vignetted at 16mm, when stacked). Using the Canon 16-35 f4, the step up ring, CPL then the ND filter there was not any perceivable vignetting.
The CPL is easy to turn beneath the ND and obviously, with no thread, there is no need for a rotating collar. This means the CPL can be made much thinner and thus the stack is thinner, thus less vignetting. Theoretically, with less glass, you potentially have less issues with aberrations too (not tested). They come with the usual anti-reflective coatings you would expect and made with high-grade optical glass.
|77mm Step-up Ring||6|
|ND Filters (77mm)||16|
|4 Piece kit||132|
|5 Piece Kit||148|
I have only used these for a few weeks, on an off, but I think enough time to assess their functionality, quality and usability. First off, the pre-production samples I felt lacked adequate magnetism. I showed these to others, who felt the same. The fitment was fine, with no vignetting when stacked, very easy to fit, take apart, and the step-up adapter was easy to thread on. My main initial issue was that the magnetic bond was too weak to be safe. A simple knock, especially with cold fingers, would easily knock the filter off and when stacked the extra weight made it worse.
I got back in contact with Kase UK and they contacted HQ. They had already noted this and said that the production version would be much stronger. This was down to an inadequate strength of the magnetic step-up ring. I was subsequently sent the full production version of the 77mm step up ring and immediately the magnetic bond was considerably stronger. I wouldn’t say it was so strong you would struggle to remove it. The K100 mag system, I tested before, was very strong, but lifting off the filter was difficult with cold fingers, as it was recessed. This mag system has gripable edges, so you can easily separate them. I felt this was now adequate to prevent loss of the filters in high winds or knocking them off by accident.
I was looking for any weakness in this system, as Kase always wants feedback, so they can improve their products. They do seem to listen and modify if necessary. Apart from the original step-up ring I couldn’t find any significant issues. One other small note is that the lens cap. Although the original cap fits the step-up ring, the recess is shallow with no threads. The Canon 77mm cap detaches too easily. I discussed this with Kase and they are producing a magnetic cap that clips on top. I think this wold be pretty cool, as it will be a low-profile cap, that can be stacked ontop, instead of the thicker and likely protruding OEM cap. A hood can be used which, for me, is a big bonus, to reduce flare and rain/spray from the sides.
The system also comes with their nice soft leather pouch with 5 compartments so it’s very easy to store the filters and stow.
The kit sizes will initially be for 82mm and 77mm lens threads and subsequently 67mm and 72mm with the assocated step-up adapters. Further adapters could then be purchased.
The system for me, as I don’t use graduated filters, seems, both on paper and in use, a great solution to a few issues I have encountered over the years with screw in filters. I have summarised what I think are the take-home points about this system. No system is perfect and can’t provide the ideal solution for every camera setup or situation, but I think improves many of the practical niggles you get with screw in filters.
- Lightweight, low-profile filtration
- Stackable filters without vignetting
- Easy to fit and disassemble due to a magnetic attachment (reduced cross-threading)
- Thinner glass
- Space saving kit design (all filters in one pouch)
- A lens hood can be used
- Not as water-tight as a screw-in system (if required)
- Filters can be (potentially) lost more easily as not screwed in
- Potentially slightly less polarization than a thicker screw-in filter
My understanding is there will be two retail versions; the 4 piece will be supplied with two ND filters, namely, a 3 stop and a 6 stop ND and a circular polariser and an additional 10 stop in the 5 piece version.
The cost of the systems is to be announced soon, but Kase UK suggest to me that the filter kits will be the most economical way of buying the filters, rather then individually, and will be in a similar price range to the screw-in filters. Stay tuned to the Kase UK Facebook page for future information.
Disclaimer: I was not paid to write this article nor was I given the filters to keep. I returned the filters in the condition they were sent to me by Kase.