Laowa 105mm f/2 STF

Updates
05/17/2017: Field Test & Gallery Images added

Laowa 105mm f/2 STF Field Test

Fully-manual portrait lens offers great image quality & beautiful bokeh

by Jeremy Gray | Posted 05/17/2017

f/2.0, T3.2, 1/640s, ISO 100. This image has been modified. Click for originals: JPEG and RAW.

The Laowa 105mm f/2 T3.2 Smooth Trans Focus lens is a distinct optic -- as are all the lenses in the Chinese company's lineup, actually -- and it performs quite nicely as a portrait lens or general telephoto prime. The fully manual lens employs an apodization element, which is unusual and allows the lens to produce particularly pleasing out of focus areas, or bokeh, while maintaining subject sharpness. After testing the lens on my Nikon D800E, I have come away impressed although with caveats that render the lens difficult to recommend for every shooter. Let's look at this unique lens and what it offers photographers.

Key Features and Specifications

• 105mm focal length with a full-frame image circle
• Maximum aperture of f/2, but maximum T-stop of T3.2
• Two manual diaphragms, one with eight blades and the other with 14
• Manual focus lens with engraved focal distance and depth of field markings
• Metal construction
• Close focus distance of 2.95 feet (0.9 meters); maximum reproduction ratio is 1:6.3
• Available in Canon EF, Nikon F, Pentax K, Sony A and Sony E mounts
• Costs around US$700

Construction and Handling

The Laowa 105mm f/2 STF lens is ruggedly built, constructed with a metal barrel and ridged metal rings. While I can't be certain about the lens's longevity given my brief amount of time with it, it feels like it would hold up to extensive use very well. It's rare to buy a new lens that feels as solid as the Laowa 105mm. In addition to its metal construction, all the lens's markings are engraved.

Less impressive is the included lens hood, which is plastic and does not lock onto the lens. The hood doesn't screw onto the end of the lens very well and gets caught on the lens cap. Removing the cap before attaching or removing the lens hood is recommended. The lens hood does its job, but compared to the lens itself, it feels cheap. Another small issue I have with the design of the lens is that the only visible marking for mounting the lens is on the mount itself, where there is a small red dot. It would be nice if there was a mark on the barrel so it would be easier to position the lens for mounting.

Metal construction and a fast maximum aperture comes at the cost of weight. The Laowa 105mm f/2 is not particularly large, measuring 3.89 inches (98.9 millimeters) in length with a diameter of 2.99 inches (76 millimeters), but it is quite heavy at 1.64 pounds (745 grams). The lens barrel doesn't change length while focusing the lens, but the front element does move. The lens barrel doesn't rotate while focusing, so you won't have to worry about an attached 67mm filter rotating while focusing.

On my D800E with vertical grip, the lens balanced nicely. But on a smaller DSLR, such as a Nikon D5600 that I have for a Field Test, the lens can create a front-heavy combination. Overall, the lens's construction is impressive.

As I mentioned, the focus ring is ridged. It is roughly 1.25 inches (32 millimeters) wide and offers plenty of surface area to get a nice grip. The ring rotates smoothly, but also with a good amount of resistance, which makes it easy to make very small, precise adjustments to focus. Plus the lens is marked with many engraved focus distances, so that helps too, because manual focusing on modern digital cameras can be rather tricky (more on that later).

One aspect of the focus ring which is a mixed bag is how much rotation is required to move from one end of the focus range to the other. In total, it's about 270-degrees of rotation to go from the close focus distance of 2.95 feet (0.9 meters) to infinity. This means that you can make very precise adjustments to focus, but it also means that going from a 3-foot focus distance to a 5-foot focus distance, for example, requires a lot of rotation which can be slow and cumbersome in the field. It can be difficult to hold the lens steady enough to dial in focus when shooting handheld because of how much rotation is sometimes necessary, especially when shooting a close subject with which you are trying to fill the frame.

The aperture and Smooth Trans Focus (T stop) rings have engraved markings as well but are unsurprisingly much narrower than the focus ring. The ring closest to the lens mount is the aperture (f/stop) ring and has spaced ridges for grip. It clicks every full stop, which is nice tactile feedback to have. The T stop ring is roughly the same width and is positioned nearly halfway between the focus ring and aperture ring. The entire T stop ring is ridged and it is declicked, meaning that movement from T3.2 to T8.0 is entirely smooth. The lens is marked at T3.2, T4, T5.6 and T8.

The Laowa 105mm STF lens has 11 elements across eight groups, including an APD element, a high refractive element and three low dispersion elements. The lens is designed to offer sharp images with minimal aberrations while maintaining a smooth out of focus rendition and buttery smooth bokeh. It delivers on all counts, as I will discuss further in the next section, but you can see its MTF chart and optical structure below.

While it is not easy -- at least not for me -- to come to grips with the specific mechanics of an apodization element, what it essentially does is create smoother transitions from in focus to out of focus areas. This is most evident when looking at out of focus highlights. The apodization element gets darker as you move toward its periphery, which changes how the aperture is rendered in an image. With a typical lens, an out of focus area has hard edges, but when shooting through an apodized lens, the aperture is not a hard black edge but rather a gradual fade from fully translucent to black.

The lens's aperture mechanism uses an 8-bladed design whereas the stepless T-stop diaphragm utilizes a 14-bladed design. This second diaphragm impacts how much light is transmitted to the sensor versus a traditional f-stop aperture which impacts more considerations, such as depth of field.

Click for full-size JPEG files of each image above: T3.2, T4, T5.6 and T8.

f/2.0, T3.2. An aspect of the Laowa 105mm that I didn't care for when shooting wide open on a full-frame camera is the cat's eye effect of out of focus areas. This is reduced when stopping down the T stop, but it can be a bit distracting when using the lens wide open.

f/2.0, T8.0. You can see that the effect is not present at T8, but at that T stop, the pleasing bokeh effect of the lens is essentially lost.

Left image (f/2.0 and T3.2) versus right image (f/2.0 and T8). Here it is evident how changing the T stop effects the background. Further, the T3.2 image was shot at 1/2000s whereas the T8 image was shot at 1/250s.

Image Quality

An advantage of a lens with apodization is that you can maintain very sharp in-focus areas while rendering out-of-focus areas very smoothly. The Laowa 105mm f/2 STF delivers in this regard. While it can be a bit tricky to nail focus, when you do, you're rewarded with outstanding sharpness and detail.

f/5.6, T3.2, 1/250s, ISO 100.

100% crop of image shot at f/2.0, T3.2, 1/200s, ISO 100. Click to view full-size: JPEG and RAW.

As you can see in the images above, this is a sharp lens. Further, it exhibits minimal distortion, which is to be expected given its 105mm focal length.

The lens doesn't exhibit particularly bad light falloff, even when shooting wide open on a full-frame camera. For portraiture, one of the prime uses of the lens, it isn't necessarily a bad thing to have a bit of falloff. If you don't like the vignette, it's easy enough to correct during post-processing. Stopping the lens down does even out the exposure across the frame a bit.

Example of vignette at f/2.0, T3.2.

Example of vignette at f/8.0, T3.2.

When using this lens, I had no issues with chromatic aberration or purple fringing. I did find that the lens didn't deliver a particularly high contrast image, but colors were rendered nicely. That is a subjective evaluation of the lens, and naturally others may feel differently about the optical qualities of the Laowa 105mm, but I found the images it produced to be pleasing to the eye.

This 100% crop of a RAW image shot at f/2, T3.2 (processed with ACR defaults) shows very little purple fringing. Consider too that there is not a lens correction profile applied, so there is zero lens correction being applied to the file.

In the Field: Portraits with the Laowa 105mm f/2 STF

When shooting portraits with the Laowa 105mm f/2 STF, some usability issues arose and my limited experience shooting portraits was exposed. Naturally, an aspect of the lens that's great is its very shallow depth of field. That's a double-edged sword though given its manual focus design. A model moving even a fraction of an inch can make a big difference when shooting with the 105mm f/2 STF. Unlike autofocus-equipped lenses, your camera won't deal with this for you as you shoot, but rather you must continually dial in focus -- not an easy feat through a viewfinder, even on a full-frame DSLR. Fortunately, by placing your focus point over your subject, you can use the in-viewfinder focus indicators to help. It can be satisfying to capture a sharp shot, but the nature of the lens means that you will be slowed down in the field.

f/2.0, T3.2, 1/320s, ISO 100. This image has been modified. Click for originals: JPEG and RAW.

When holding the lens and constantly moving the focus ring, it is a bit too easy to accidentally move the STF or f/stop rings. Further, sometimes my Nikon D800E metered oddly with the lens. Considering how much I have used the D800E, I'm inclined to point the blame at the lens rather than the camera. Your experience may vary, but it is worth pointing out that metering was not always consistent during my shooting. Further, I needed to use +0.67 exposure compensation often.

f/2.0, T3.2, 1/640s, ISO 100. 50% crop of a modified image. When shooting wide open, the depth of field is very shallow.

With that said, I very much enjoyed shooting portraits with the Laowa 105mm f/2 STF lens. It's a very sharp lens when focus is dialed in correctly, and it produces creamy out of focus areas. I also enjoyed how the lens rendered scenes, especially regarding color. The lens doesn't have quite the same saturated, high-contrast punch as some other lenses I've used, but that is not necessarily a bad thing.

f/2.0, T3.2, 1/100s, ISO 100. This image has been modified. Click for originals: JPEG and RAW.

Laowa 105mm f/2 STF Hands-on Summary

What I like:

• Capable of producing very sharp images
• Excellent bokeh
• Very good build quality
• A nice portrait prime lens
• Precise focus ring

What I dislike:

• While great for dialing in focus, the focus ring requires a lot of rotation to go through the focus range
• It is a bit too easy to accidentally rotate the STF and f/stop rings while shooting
• Cats eye bokeh near edges of frame on full-frame
• Fully manual lens means just that, which may not be everyone's cup of tea
• Poor lens hood design

The Laowa 105mm f/2 STF lens is an interesting prime optic. It delivers exactly what it promises - sharp in-focus areas with silky smooth out-of-focus areas. For photographers willing to shoot with a fully manual lens, the Laowa 105mm f/2 STF might be right up your alley.

f/2.0, T3.2, 1/400s, ISO 100. Click for full-size images: JPEG and RAW.

Personally, I enjoyed working with the lens. Sure, it can be frustrating to have to dial in focus when shooting a moving subject and with such a shallow depth of field, even a slightly moving portrait subject can prove problematic. But if you are okay with some missed shots, you will be treated to beautiful images. The lens can deliver very sharp images and there is something innately satisfying about dialing in everything manually and getting a great shot.

f/2.0, T3.2, 1/1000s, ISO 100. This image has been modified. Click for originals: JPEG and RAW.

If you are looking for a portrait prime lens, give this Laowa 105mm f/2 STF a long look. The price is right, the build quality -- sans the hood -- is very good, and the lens shoots beautiful photographs.

• • •

Laowa 105mm f/2 STF - Overview

(From Venus Optics / Laowa lens literature) The new Laowa 105mm f/2 Smooth Trans Focus Lens incorporates a unique optical design with an apodization (APD) element next to the aperture. The APD element resembles the function of an ND filter which becomes thicker towards the perimeter, gradually reducing the amount of light transmission towards the periphery to produce a soft, natural and beautifully diffused out-of-focus rendition (called bokeh).

The new Laowa 105mm f/2 Smooth Trans Focus Lens offers two separate diaphragms. The stepless 14-bladed perfectly circular aperture, in conjunction with the apodization element gives this lens the ability to produce smooth and pleasing bokeh. It is also useful for videographers to control the amount of light that passes through the lens. The 8-bladed aperture is to determine the effective aperture opening (f-number) and the depth-of-field.

The lens houses 11 elements in 8 groups with 1 High Refractive element, 3 Low Dispersion elements and 1 Apodization element. This optical design is proven to deliver images with extreme sharpness and minimal chromatic aberrations. The enclosure of the lens is made of metal to strengthen its durability. Canon EF, Nikon F, Sony FE, Sony Alpha and Pentax K mounts are available.