Way back when, when I started working with rectangular filters I thought it would be a brilliant idea to build the holder so that it snapped onto the lens’s hood mount instead of screwing into the filter threads. After all, when you have a filter holder attached, you can’t use the lens hood anyway.

I apparently wasn’t alone in my desire to use the lens hood mount to attach a filter holder. Late last year, I was approached by Héctor González of 3D Printed Ideas (3DP Ideas). He was in the process of spinning up a new business centered around 3D Printing and producing Cokin Z-Pro filter mount adapters that attached to the hood mount on various Canon lenses. Suffice to say, it didn’t take much to convince me of the genius of the idea.

Full disclosure; unlike most of my reviews, this item was not purchased by me at retail. It was provided by the manufacturer for me to test and evaluate, at no cost to myself.

One note I would point out, one of the big advantages of 3D Printing these filters, is that Hector can refine the design at will without having to have dies recast and inventory cleared out. In the time between when my holder was printed (in early December of 2013) and when I’ve completely my review, Hector has refined the design further to better block any stray light that may enter from the bayonet mount.

Cokin’s systems aren’t the most elegant solutions for those who use wide-angle lenses. The design of the Cokin holders essentially stacks the adapter, then the holder core, then the filters. As a result, the holder slots and filters are pushed further away from the front of the lens, where they more easily intrude in the lens’s field of view. The poor handling of ultra-wide angle lenses (wider than about 20mm on a full frame camera) is one of the reasons I switched from Cokin’s system to Lee’s system where the design affords an overall shallower mounting situation.

The 3DP Ideas mount adapter goes a long way to rectifying the inherent design flaw in Cokin’s system. By attaching to the hood mount, it doesn’t rely on the filter threads at all. Instead, the adapter has been designed to position the front of holder core just ahead of a standard thickness screw in circular polarizer. Moreover, the filter can be mounted without removing the attached protective filter or in conjunction with a standard circular polarizer instead.

Hector sent me an 83mm diameter mount for testing. This specific mount works on a number of Canon lenses including the EF 24-105mm f/4L IS USM, EF 100-400mm f/4.5-5.6L IS  USM and EF-S 10-22mm f/3.5-4.5 USM (see 3DP Ideas site for full compatibility information).

I used a Canon EF-S 10-22mm f/3.5-4.5 USM on an EOS M with an EF-EOS-M mount adapter for the vignetting testing. The 3DP Ideas mount places the front plane of my Cokin holder about 8.5mm ahead of the front plane of the 10-22’s filter threads. This leaves enough clearance for a standard depth circular polarizer (typically 7mm) without coming close to the back of the filter in the first slot.

The following series of images show the performance of the holder + filters.

Note in these images, the left side of the holder has been configured for 2 filter slots, and the right side has been configured for 3 filter slots.

The holder performs a little worse than using the Cokin screw in ring without a protective filter or CPL. A 2-slot configuration (left) didn’t vignette, but a 3-slot configuration (right) would. Though honestly, a lot comes down to how you want to classify a vignetting as a fail, is less better or is less still some and therefore not acceptable?

• 3DP Idea adapter & holder
• Cokin Adapter & holder
• No filter, holder, or adapter

Adding a protective filter to the lens the situation reverses compared to the filter free setup. While there’s often a lot of hot debate over whether you should use a protection filter, I do as a lot of the time I’m using my lenses there’s salt spray and blowing sand, and it’s a whole lot easier to rinse a protection filter off to clean it than worry about cleaning the front element.

In any event, as shown in the set below, while the 3DP Ideas adapter still causes the slots to vignette in the 3-slot configuration (right), the standard Cokin screw in ring vignettes in both the 2- and 3-slot configurations.

• Protection + 3DP Idea adapter & holder
• Protection + Cokin Adapter & holder
• Protection, no holder, or adapter

Adding a CPL, or even a simple protective filter, to the mix, pushes the Cokin ring further away from the lens, resulting in vignetting from both the 2- and 3-slot configurations. Since the 3DP Ideas mount isn’t affected by filters, the situation remains the same as the first test; the 2-slot configuration (left) doesn’t vignette, and the 3-slot configuration (right) does.

• B+W CPL + 3DP Idea adapter & holder
• B+W CPL + Cokin Adapter & holder
• B+W CPL, no holder, or adapter

My testing showed that to remove vignetting completely with the Cokin holder and the 3DP Ideas mount you would need to work no wider than 12mm with the EF-S 10-22 on a crop sensor.

3DP Ideas could further improve the 3-slot vignetting situation by offering a shorty mount, though doing so would certainly preclude the use of a screw in filter.

Fit and finish on the sample part I received was good. Hector is, at least at the time of the writing, using Polyjet 3D printing technology to make these parts. The surfaces are quite smooth, and the material seems to be reasonably solid. However, heating the material past about 125°F will cause it to soften and eventually fail. I don’t see this being a significant issue in day-to-day use, but it’s something to be aware of in extremely hot climates, especially if the adapter is kept in a black pouch that might be in the sun for long periods.

I did a limited, non-scientific, testing to see if there were any obvious problems with cold performance to the extent that I could test. Extreme cold, something my freezer certainly doesn’t reach, often makes material brittle and much easier to break. I left the ring in the freezer at 0°F (-18°C) for a couple of hours before twisting it slightly to see if it appears any more brittle than at room temperature. While the adapter is certainly stiffer, at these temperatures it doesn’t appear that becoming brittle will be a problem.

The 3DP Ideas mount adapter leaves about 4.25mm of clearance between the rear of the Cokin core and the threads on the lens. If you’re using a low profile protective filter or polarizer (anything 5mm thick or thinner), you’ll be able to attach the mount adapter to the lens, the slide the Cokin holder on over it. Otherwise, you’ll need to slot the adapter into the filter holder before attaching. Since the adapter uses the bayonet mount, only a quarter turn is necessary to lock it in place.

That said, while the bayonet mount is certainly the biggest strength to these adapters, it’s also their biggest weakness. How well the mount adapter stays put depends heavily on the condition of the lens’s hood mount.

A metal mount, such as the one found on my EF 24-105mm f/4L IS USM, doesn’t wear a lot and makes for a very solid fit—so much so that it was almost hard to get the adapter off the lens. On the other hand, the well-used plastic hood bayonets on my EF-S 10-22mm f/3.5-4.5 USM and EF 100-400mm f/4.5-5.6L IS USM, were worn to the point that rotating the holder on the adapter, would actually rotate the adapter off the mount.

I don’t see much that Hector could do to adjust the design to improve the situation. Making the mount tighter would just make it harder to put on an un-worn lens. The best solution if your particular lens mount is loose, seems to be to just stick a small piece of gaffer tape to the adapter and lens to keep it in place.

Hector from 3DP Idea’s has done a solid job addressing some of the deficiencies in Cokin’s mounting method. Though clearly, there’s only so much he can do in an effort to fix Cokin’s holder before designing his own holder is more effective.

Hector is currently offering 3D Printed plastic adapters for Canon lenses that use -83 and -88 hoods for Cokin’s Z-Pro and Lee holders. These all run about $40 plus shipping. He’s said he’s working to extend his product line to include Nikon versions of these adapters, plus he’s working on an aluminum version of the Lee adapters with only enough offset for a slim line (5mm) filter to fit behind it.

You can buy these adapter direct from 3D Printed Ideas’ website.