Living with Photography: Fujian's 35mm F/1.7 CCTV Lens

By Norman Chan

Testing a $25 toy lens from eBay, which produced some surprisingly cool results.

Two weeks ago, New York-based Lomography launched a Kickstarter to raise money to manufacture modern versions of the 19th century Petzval portrait lens for use with DSLRs. The Lomography Petzval lens takes its design and engineering inspiration from a 1840s lens that revolutionized portrait photography with a then-unheard of aperture of f/3.7. To achieve that speed, the hefty brass lens was designed to have a fairly narrow field of view due to a high field curvature, meaning that only a small portion of the entire frame could be in focus. That look--a very sharp center focus surrounded by visually distinct vignetting and bokeh--is something that Lomography is touting as a prized feature of its new Petzval lenses, and there's no doubt that the portraits taken by these lenses stand out.

But the new Petzval lens also costs $400. While that isn't on the high-end of specialty lens prices, it is a hefty investment considering plenty of other standard lenses you can buy with that budget. After sitting on the Kickstarter pledge for a few days, I decided to back out. That decision was also prompted by a reader who pointed me in the direction of a cheap lens for NEX cameras that he claimed could produce a similar effect. And by cheap we're talking about $25, shipped. That sounded unbelievable. Given that my Sony NEX camera has taken a back seat to my full-frame 6D, it was about time to have fun with it again.

This is the Fujian 35mm f/1.7 C-mount lens. It's a cheap lens made in China for use in, of all things, CCTV security cameras. The C-mount is just a male screw thread about 1-inch in diameter, used in old 16mm cameras, CCTV cameras, and even laboratory equipment. The small size of the mount makes it suitable for adapting to micro four-thirds and NEX cameras without much vignetting (more on NEX than m4/3), and these lenses sold on eBay regularly come with mFT or E-mount adapters. I bought mine on eBay for $25 with an E-mount adapter and two small 5mm macro extenders. As it turns out, a similar lens is also sold by a company called SLR Magic, but costing $150. Fujian 35mm advocates have called these out as being basically the same lens, so opt for the $25 import instead of the rebranded/modified one. What you're paying for with SLR Magic's lens is quality control and a native mount.

Mounting the lens is a cinch--there's not much hardware here. You simply screw the lens onto either the adapter plate or the macro extenders, and then click that plate into the NEX camera body like any other E-mount lens. There are no electronics built-in, but you do get two grippy plastic rings for focus and aperture. The rings are labelled with focal distance and aperture number, but they're not aligned and there are no markings on the lens to show you what setting you're actually at. It's basically all trial and error with this lens when stopping up from f/1.7 all the way to f/16. Still, the metal lens is solidly-enough built and easy to remove from the camera.

But how about the photos?

Given the relatively open aperture of f/1.7, my instinct was to shoot everything as wide as possible. The NEX kit zoom lens only opens up to f/3.5 at 17mm, and even the $1000 24mm Carl Zeiss lens we've rented before only opens up to f/1.8. The 35mm focal length on the Fujian has a near 100% coverage of the NEX's sensor, so it's the rough equivalent of a 35mm E-mount lens (or ~50mm full-frame).

At its widest aperture, the Fujian gives a very shallow plane of focus, as shown in the photo below. Here, you can see the distinct bokeh that the Fujian is known for. And while the bokeh is "buttery" smooth, I wasn't impressed by the sharpness of the in-focus area in this photo. Even at ISO 200 and a shutter speed of 125, the in-focus areas looked slightly blurred and had pretty nasty light flaring. I soon realized that this was due to framing--the field curvature of the lens makes it look like the bokeh is radiating from the center of the frame, as opposed to the point of focus. That also means that only the very center of the frame is going to get the best optical focus of the lens. The Fujian requires framing for the focus at the center and then cropping in post for optimal sharpness--I presume the Petzval lenses will as well.

Unlike other lenses, closing up the aperture didn't increase sharpness at all, either. Below are two examples of photos taken at f/1.7 and (roughly) at f/5.6. Closing the aperture flattens the scene up just a little, but the quality of the glass just isn't good enough to yield good images when less light is let in. In practice, I found that aiming for a f/2-f/2.8 was the sweet spot for the Fujian lens and shooting moving subjects. Another note: the shortest focusing distance for this lens is about a foot and a half.

Here are a bunch of photos I took with the Fujian outdoors, shot in RAW and post-processed a bit in Lightroom after the fact. You can see how susceptible the lens is to light flares and hazy bokeh in bright daylight. Another caveat of the C-to-E-mount design is that focusing to infinity doesn't actually work properly. Normally, when you want to take a photo of something in the far distance, you snap the focusing ring all the way to infinity. With the Fujian and E-mount adapter, infinity is actually focused at the one-foot mark on the lens ring--going past that will focus past infinity, meaning the area of focus is past the image plane. (This isn't useful for normal shooting, but does have some implications for macro.)

The photos turned out OK--but nothing that really jumped out at me as being special. At this point, I wasn't too hot on this lens, regardless of the price.

It wasn't until I started using the macro extenders that came with this kit that I started really liking this lens. The kit came with two 5mm adapters, and even with both attached, the macro effect wasn't as extreme as the 13mm EF-mount extender I have been using with the Canon. Here's a photo taken with both 5mm extenders attached, of a small 1/6th scale figurine head.

With a singular 5mm extender attached, I was able to get some really nice "macro" shots. Put on the 35mm Fujian, this had the effect of what looked like a 85mm portrait lens (my guess, since I don't have a lens to compare it to). At macro, you're limited by both how close and how far you can place the lens away from a subject, since infinity focus doesn't apply. But given that the Fujian focuses past infinity, I was able to take photos about two and a half feet away from subjects, which yielded really nice "half-portraits":

The sharpness and bokeh were really great in these photos, even though I couldn't fit a whole head in frame in either portrait or landscape. I could see this lens being great for child or pet portrait photography, though.

The fun I had playing around with the Fujian was well worth the $25, and it's something I'll keep as just another tool for the NEX to complement my other camera and lenses. Going back to the NEX for an extended period of time also called to attention how much better an optical viewfinder is than an LCD screen, especially when working with wide apertures. Without focus peaking set to highest sensitivity, there's no way I could've been able to grab some of these photos.

Are there other cheap toy lenses that you've tested and want to recommend? Post your recommendations and share your own experiences (and photos!) of these lenses in the comments below.