August 18, 2011
Mounting a Lee SW150 Filter Holder on a Canon TS-E 17

The Canon TS-E 17mm f4 L is a fantastic lens for landscape photography where an extreme wide-angle perspective is required. The main drawback with the lens is that it's not possible to use neutral density filters without a little DIY (do it yourself) work. I was inspired by Aender Brepsom's article where he modified a TS-E 17 lens cap to support a Cokin X-Pro filter holder, and have used a similar solution to mount a Lee Filters SW150 Filter Holder for the AF-S NIKKOR 14-24mm f/2.8G ED.

The problem with mounting filters on a TS-E 17 is the bulbous front element, and the solution begins with the bayonet-like mounting ring for the lens cap (Figure 1). I started by cutting an extra TS-E 17 lens cap just above the split in the cap (Figure 2). I cut the cap without disassembling it like Aender Brepsom did, and therefore I didn't have to re-assemble it when I was done. Then I beveled out the inside of the cap to increase the viewing angle. Then I cut a notch in the outer Lee SW150 mounting ring to make room for the lens cap release (Figure 3). The two inner pieces of the SW150 adapter for the Nikon 14-24 are not used. Then I cut "biscuit slots" in the bottom of the lens cap to create something for the epoxy to latch onto (Figure 4). The inside of the SW150 mounting ring is threaded, so there's already something for the epoxy to grab onto on that side. Then I slipped the modified lens cap down onto the modified SW150 mounting ring (Figure 5) with the ring and lens cap both in the same orientation as in Figures 3 and 2, respectively. It's a nice snug fit, and there's just enough room to access the lens cap release with my thumbnail. Then I filled the gap on the bottom between the modified SW150 mounting ring and the modified lens cap with epoxy, and I stayed away from the release mechanism (not shown). The DIY SW150 adapter attaches to the front of the TS-E 17 just like the lens cap (Figure 6). Then the main SW150 filter holder can be mounted from the body side of the lens (Figure 7). Alternatively, the filter holder can be attached to the DIY adapter and then the whole assembly can be mounted as one unit from the front of the lens. Here's a view along the filter supports (Figure 8).

With the lens stopped down to f8, there is no effect on the image when the lens has no shift or tilt, and I have not yet evaluated the effect of shift or tilt. There is plenty of excess plastic on the remnant of the lens cap, so I'll probably remove some more to reduce possible vignetting when shift and/or tilt are used.

Addendum

I have since removed some additional plastic from the remnant of the lens cap and have tested the lens at f5.6 with tilt and shift motions. It looks like there's no problem with vignetting. I took all vertical shots with the filter rails aligned to take the filter from the top, like for a graduated neutral density filter, and could see no difference between clean shots and shots with the filter holder installed, even at f5.6 with 5° of tilt and 10mm of shift simultaneously. The lens can go to a maximum of 6.5° of tilt and 12mm of shift. In my experience shooting real-life scenes, I haven't used more than about 3° of tilt, and the corners start to get a bit soft by 10mm of shift.

Addition on September 24, 2013

Lee Filters has announced on their website an adaptor to mount their regular Foundation Kit, which holds 4" or 100mm filters, on the Canon TS-E 17mm.