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. 

A Taller Stack (of pancakes)

Order Up: My new (fourth) pancake lens, a Viltrox 28mm F 4.5, has gotten rave reviews since its introduction in 2024. As a photographer, there has to be some good reasons to justify its purchase. To wit: 

• It is cheap: The MSR, if that applies to web-exclusive purchases, is just shy of $100.00, or maybe less if you shop around. I've seen them as low as $70 on eBay, as of today. I opted to pay the full Benjamin on Amazon to ensure prompt delivery.
• It is sharp: Reports have universally praised the lens for its sharpness, and it lived up to the hype based on my limited experience.
• It has autofocus: This lens is probably the lowest priced autofocus mirrorless camera lens. It bumped the former low priced champion, the 7artisans 27mm F 2.8.
• It offers full-framed coverage: This is the big one. On a Fuji APS sensor body, its a "short normal" lens. On a full-frame Sony it is a true wide-angle lens. For me, this makes the lens better aligned with my street photography philosophy of "Wider Is Better".

Meh To Blah: You have to be realistic about your expectations on a lens made to fit this price point.

• Type C USB Port: Like my TTartisan 28mm 2.8, this lens can update its firmware using a USB port, although Viltrox chose to put the interface in the lens mount. If you do buy this lens and find yourself needing an firmware update, view this video first. It makes the process appear almost simple. 
• Fixed 4.5 aperture: I do not know if this was a concession to the price point or the lack of internal space. Nonetheless, the lens has a fixed, non-adjustable aperture of 4.5.  If we were to follow the tried and true "Sunny Sixteen Rule", setting your camera to an ISO setting of 100 would require a shutter speed of shorter than 1/800 of a second for a proper "bright sunlight" exposure. I have a partial work-around, which I'll discuss -later. Don't expect any dramatic front-to rear depth of field photos with such a large aperture.
• Long Minimum Focusing Distance: The online specifications set the minimum focusing distance to about .3 meters, or about one foot. Not an issue for a  general purpose lens, but a limitation worth remembering.
• Sliding Lens Blinder. In spite of its tiny size, the designers managed to squeeze in a sliding blinder that protects the lens. There is a knob on the front lens bezel that, when rotated clockwise, retracts the blinder allowing the lens to extend slightly and assume the "ready position". I neglected to mention this in my first post, but as you will see, this feature will become inaccessible as I start adding accessories to the lens.
• No Provisions For Filters: With a fixed aperture of 4.5, a neutral density filter could certainly help control exposure, assuming that one could be attached. While Viltrox made no such provision, some clever people at Filmatura created an adapter to mount a 52mm filter to the Viltrox lens barrel. Check out the video here.

Out Of This World. I make joke. Here is a photo, taken from the website, of the 3-D printed Filmatura adapter. It is threaded to accept 52mm filters from the front while having a friction fit on the barrel of the Viltrox lens on the other end. Currently, it is in transit from somewhere on the planet, so the cloud background is sem-appropriate. When it arrives, I will have a 52mm polarizing filter I can play with, and an assortment of 49mm accessories adapted for use from a 49mm female threaded Fuji X100 filter pack. When the adapter arrives I will experiment with my filtration options.  I do not know if any of my current accessories will induce vignetting in the frame corners, so I'll just have to see what I'll need to buy so I can make everything work together. 

Christopher Frost has an excellent review of the lens. View it by clicking here.