Metal Threads For Your Plastic Adapter

As wonderful as the Viltrox 28mm F 4.5 lens is, it isn't perfect. As I mentioned in an earlier post, the lens has has no means of attaching a filter. This could be a big thing because the fixed F 4.5 aperture is pretty wide, and it would be helpful if a neutral density filter could be attached to provide a means of controlling the exposure other than ISO and exposure time. 

A company called Filmatura has addressed to problem my offering an adapter ring that can hold a 52mm filter and slips onto the Viltrox 28mm F 4.2 lens barrel. It is not machined from metal, but is instead created using a 3-D printer using a plastic similar to a weed-wacker cable. And while those 52mm threads can be created with reasonable dimensional accuracy, they are still plastic, and therefore subject to wear whenever a filter is screwed in or out. Cole of Alt Cine Cam suggests that users install a metal 52mm to 55mm step up ring to prevent damage to the soft plastic threads. 

Buy yours here.

Now 55mm accessories are not as common as those in 52mm, Nikon's default filter size from many years ago. As you know, filters are threaded at both the front and rear to facilitate stacking. The lens side has male threads, while the side facing the world has female. The filter's optical glass disk is usually held in place with a narrow, threaded retaining ring can be unscrewed using a lens spanner wrench like the one pictured here*. By spreading or compressing the two spanner blades, you can adjust the width to accommodate almost any filter size. I found this spanner on Amazon, but many REAL camera stores may have these spanners available for sale, but be sure to call first. In a pinch, you can clamp two thin screwdrivers in the jaws of a bench vice, but these spanners are not that expensive, and useful for other projects.

Now for the filters. While you're at the camera store, ask to see if they have any old colored filters for black and white photography, with yellow, red, and green the most common. They can be difficult to sell because so few people use black and white film, and for most photographers, the effects can be simulated by using a monochrome preset in a digital camera. Very often these filters are just thrown in a drawer, and some dealers may just give them away. Don't worry if they are scratched since you will discard the glass anyway. Just be sure that the filters you choose do not have dented rings which can impede the removal of the retaining ring. 

I would up digging through a tub of discarded filters and lens hoods at a local camera store and found a like-new Hoya filter which I paid $5.00 (ouch!) for. Oh well, it's still cheaper than the worst new filter on eBay.

Once you've found a suitable filter, adjust your spanner to engage the two tiny slots located on the retaining ring. Look carefully, as they are very narrow. Use a piece of discarded rubber glove to hold the filter ring in the palm of your hand. Now engage the retaining ring slots with the spanner and carefully, but firmly, unscrew the inner retaining ring. After several turns you will now have an adapter with both male and female threads which you can screw  permanently into your plastic filter holder. The brass/aluminum filter ring you've just installed will certainly outlast the softer plastic threads.

Here's the actual video. If you can cut to the chase, advance to 1:28. 

*  I've also seen manufacturers use thin wire snap rings, perhaps as a cost saving gesture, or possibly to prevent warping of the glass.

Post Script: My order for the adapters was made on May 8, 2025 and delivered on May 20. Twelve days from the Czech Republic. Oh, a signature was requied upon receipt.