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Laowa 105mm f/2 T3.2 Smooth Trans Focus Lens Review

Laowa 105mm f/2 T3.2 Smooth Trans Focus Lens Review - John Riley reviews the Laowa 105mm f/2 STF lens designed to give creamy bokeh.

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Venus Laowa 105mm f/2 STF in Interchangeable Lenses

Handling and Features
Performance
Verdict
Specification

Laowa 105mm Stf Front Oblique View

Laowa are one of a few manufacturers who are producing very interesting and innovative niche lenses. The Laowa 105mm f/2 Smooth Trans Focus lens is one of a handful of optics that utilize an apodization element. This is said to help produce sublime bokeh whilst maintaining a critically sharp subject. Let's move deeper into the world of optics and see what this really means, and whether or not in practice there is a real benefit to be seen.

Laowa 105mm f/2 T3.2 Smooth Trans Focus Handling and Features

Laowa 105mm Stf On Nikon D810

The lens is a substantial one, manufactured using metal and intended to be extremely durable. It has 11 elements in 8 groups, including one HR (High Refractive Index), three LD (Low Dispersion), two floating elements and one special Apodization element. This last is a graduated neutral density element that becomes darker towards the edges, concentrating the light towards the centre of the frame and reducing or removing the Airy disc effects normally caused by diffraction. This is said to improve the bokeh, the quality of the out of focus areas, and leads Laowa to describe their new lens as “The Bokeh Dreamer”.

Hand in hand with this are two separate diaphragms. A conventional 8-bladed aperture controls the f/number in the usual way. Like the lens, which is manual focus only, this diaphragm needs to be stopped down manually to make a correctly exposed capture. The f/number relates to the physical aperture in the usual way, controlling exposure and depth of field.

The second diaphragm is a stepless 14-bladed manual design, marked in T stops, or Transmission stops. This actually gives the transmission value of a lens, the amount of light that actually reaches the sensor. This can be a different exposure to the f/stop, although in practice the two are considered the same in stills photography. In movie shooting, T stops are used, and the stepless diaphragm provided here is ideal for movie work. There are a limited number of T stops provided, from T/3.2 to T/8.

Laowa 105mm Stf On Nikon D810 With Lenshood

Either one or the other of these diaphragms is used, the unused one being left wide open. This does cause some handling issues, certainly on the Nikon D810 that was used for this review. The camera's exposure measurement was very unreliable with this lens and other methods, such as estimating exposure or even a separate meter, may be helpful. When using the f/stops, operating the stop down lever whilst manually focusing leaves the shutter release finger straining a bit to reach, but it does improve with practice. Using the T/stops is easier as the leaves stay at the position selected.

To complete the lens details, focusing is down to 0.9m (0.16x magnification), it weighs 745g and has a 67mm filter thread. The JJC lens hood provided is effective and bayonets on smoothly, but there is no click stop to keep it firmly in place. The lens is available, or shortly will be, in Canon, Nikon, Pentax K, Sony A and Sony FE fittings.

It will, of course, vary from camera body to camera body, but the Nikon D810 can be quite tricky to focus well with this particular lens. This means that we are slowed down. It could be ideal for portraiture, landscape and other fairly static subjects, rather than sports or wildlife. Despite at first being challenging in use, ways round it could soon be found and the lens proves to be rather satisfying to master.

Laowa 105mm Stf Rear Oblique View

Laowa 105mm f/2 T3.2 Smooth Trans Focus Performance

This lens is manual only in every respect, having no electronic communication with the camera, at least in Nikon mount. Focusing depends very much on the screen in the camera, and modern AF screens may not be the most suitable. Nonetheless, the moderate telephoto is sufficiently long to help the image snap in and out of focus.

Sharpness is very impressive throughout. Central sharpness starts off at an excellent level at f/2, approaching outstanding between f/2.8 and f/5.6, is excellent at f/8 and f/11, still very good at f/16 and only drops to fair at f/22. The smallest aperture is best avoided, as with many lenses, but is worth having there for situations where depth of field is the priority.

The edges are very close to the central sharpness figures, excellent all the way from f/2 through to f/11. Again, this drops to very good at f/16 and fair at f/22.

Sharpness tests using the T stops were also made. This makes no real difference to either CA or sharpness, and it all remains excellent throughout, centre and edge.


 

 
MTF Chart
MTF Chart

How to read our charts

The blue column represents readings from the centre of the picture frame at the various apertures and the green is from the edges. 

The scale on the left side is an indication of actual image resolution as LW/PH and is described in detail above. The taller the column, the better the lens performance. 

For this review, the lens was tested on a Nikon D810 using Imatest.

 

The distortion level measures a very low -0.162% barrel. This is excellent, with virtually no bending of straight lines at all. CA (chromatic aberration) is also virtually zero, hovering around one tenth of a pixel, which is insignificant. Another excellent result.


 

 
CA Chart
CA Chart

How to read our charts

Chromatic aberration is the lens' inability to focus on the sensor or film all colours of visible light at the same point. Severe chromatic aberration gives a noticeable fringing or a halo effect around sharp edges within the picture. It can be cured in software.

Apochromatic lenses have special lens elements (aspheric, extra-low dispersion etc) to minimize the problem, hence they usually cost more.

For this review, the lens was tested on a Nikon D810 using Imatest.

 

Flare was totally absent and cannot be seen in any of the shots taken. The coatings and hood are clearly efficient.

So, is the bokeh as sublime as suggested? Looking at the images I would say yes. The Apodization filter does seem to make a difference. There may also be a very slight difference between using the different diaphragm mechanisms. It's a subtle distinction, but the T stops might just have the edge. This may though also depend on subject matter.


Venus Laowa 105mm f/2 STF Sample Photos

Value For Money

Unique lenses can be difficult to place in context, but we do have two other lens options to compare with, albeit for specific marques.

In 1999 Minolta (later Sony) introduced the Smooth Trans Focus 135mm f/2.8 (T/4.5) lens at £939. In 2014 Fujifilm added the Fujinon XF 56mm f/1.2 R APD lens to their range, priced at £875.

Against this, the Laowa is priced at £549-649 depending on mount, which seems very reasonable.

Laowa 105mm f/2 T3.2 Smooth Trans Focus Verdict

Laowa certainly knows how to make exciting and different lenses. It's always good to see lenses that go beyond the pure technicalities, offering some unique “feel” or “character” to images. The Apodization filter is very clever, it works and the bokeh offered is indeed superb, whilst the sharpness of the main subject is not compromised in the slightest.

Despite some handling inconvenience, the lens is fun to use and a challenge to become proficient with. It may not be for everyone, but for those willing to get to grips with it the reward will be in that sublime, creamy smooth bokeh.

Laowa 105mm f/2 T3.2 Smooth Trans Focus Pros

Excellent sharpness throughout
Sublime bokeh
High-quality construction
Flare-free
Very low CA
Very low distortion

Laowa 105mm f/2 T3.2 Smooth Trans Focus Cons

Awkward manual handling
No click stop on hood
Metering unpredictable

FEATURES  
HANDLING  
PERFORMANCE  
VALUE FOR MONEY  
VERDICT  

The Laowa 105mm f/2 T3.2 STF lens is an unusual and high-quality optic with sublime, creamy bokeh.

 

Venus Laowa 105mm f/2 STF Specifications

ManufacturerVenus
General
Lens Mounts
  • Nikon F
  • Canon EF
  • Sony Alpha
  • Pentax K
  • Sony E Mount
  • Sony FE Mount
Lens
Focal Length105mm
Angle of View23
Max Aperturef/2
Min Aperturef/22
Filter Size67mm
StabilisedNo
35mm equivalentNo Data
Internal focusingNo Data
Maximum magnification0.16x
Focusing
Min Focus90cm
Construction
Blades8
Elements11
Groups8
Box Contents
Box ContentsNo Data
Dimensions
Weight745g
Height98.9mm

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Comments


josa 5 25 Czech Republic
5 May 2016 10:58AM
Great bokeh!

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I need clarification: Does the lens (when using F-Stops) stay wide open until shutter is pressed regardless of the aperture selected; thus making use of the DOF preview button (say on D7000) to take a accurate light metering? Can the lens be used in this order: compose -> focus -> DOF stop down/meter/adjust -> shoot ? lol, thanks.
11 May 2016 9:26PM
This may well depend on the camera body. I used a D810 and the metering was very erratic, so I opted for estimating instead based on the open aperture meter value. Meter at open aperture, close down x number of stops and adjust shutter speed x number the other way. The f aperture needs a constant press on the D810 stop down lever to give the aperture required, which combined with manual focusing and releasing the shutter needs a bit of practice. The T stop just stays at the aperture selected, which actually is a bit easier as a consequence. It's not the easiest of lenses to master, but it's a great lens that's worth getting to know. Hope that helps!
The aperture blades dont stay open when stopping down, do they? (like a ais or G lens) this would make my comment mute.
11 May 2016 10:16PM
The f number ones do, unless the stop down lever is kept pressed in. The T numbers stay as set.

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