DZOptics Kerlee 35mm f/1.2 Lens Review

Handling and Features
Performance
Verdict
Specification

There are some very interesting fast, manual focus lenses coming from Chinese optical manufacturers. Now DZ Optics are offering what must be the fastest 35mm lens ever, the Kerlee 35mm f/1.2. We put this impressive looking lens to the test to see how it performs and how useful that bright maximum aperture proves to be.

DZOptics Kerlee 35mm f/1.2 Handling and Features

We have a 35mm f/1.2 full frame lens, available in Nikon F, Canon EF, Sony E and Pentax K mounts. It is fully manual focus. This is the fastest lens ever offered in a 35mm lens, at least for full frame SLR cameras. It is clear from the mount options that the lens is aimed at the full frame DSLR, although it will of course also be usable on many APS-C models in the same ranges. The review copy was supplied in Sony E mount, along with a Sony Alpha a7r body. Manual operation was not the easiest with this camera, but the technique of using open aperture to focus and then stopping down to take the picture worked quite well. The aperture ring is click stopped, so focusing and then counting ten clicks gives f/8, a likely commonly used aperture, so in practice it becomes quicker as we become more familiar. The click stops can also be switched off, which is a boon for video shooters.

In any event, the mount is totally manual, with no electronics. So the aperture stays where it is put and there is no stop-down mechanism. The aperture blades actually look very impressive, being 14 in number. This gives an almost perfectly round aperture, so bokeh is likely to be very smooth.

A 35mm lens is a versatile optic, for many being a “wide standard” lens. It can be used in a variety of ways, for almost all subject matter from street photography to landscapes. The f/1.2 aperture aids focusing manually and will have implications for bokeh and whisper-thin depth of field. Flat on subjects could be tackled in very low light levels whilst still keeping a fast enough shutter speed to avoid camera shake. Interestingly, the manufacturer quotes the optimum optical quality as being between 1-5 metres, from quite close to medium distance.

The lens is a good looking beast, obviously heavy at 690g for its size and made of solid metal and glass. There are 11 elements in 10 groups, including one ED (extra low dispersion) and two high refractive index glasses. The 14 diaphragm blades look as impressive as those we might find on old brass lenses of a very different era, but here they are crisp and new and, as mentioned, bode well for smooth bokeh. Closest focus is 0.3m, giving a maximum magnification of 0.12x. Being totally manual, the only control is the on/off switch for the aperture click stops. This switch is quite small and the finish on the review sample was not quite up to the rest of the lens.

Otherwise, overall quality of finish was very high, with just that small question mark over the click stop switch. The provided bayonet lens hood, also metal, fits smoothly onto a very substantial front bayonet fitting. However, unlike most bayonet fits it will rotate continuously, there being no stop. There are click positions, but the actual fitting needs a very small turn indeed to secure the hood. Once this is realised, the fitting is smooth and positive.

Focusing at f/1.2 is very easy. As expected, the depth of field is so small that focus is a very precise point. The technique of focusing at open aperture and then counting click stops to the desired setting means that the lens can be used without taking the camera from the eye. In terms of handling, the Kerlee 35mm f/1.2 is as efficient as any manual focus lens can be.

DZOptics Kerlee 35mm f/1.2 Performance

In general, the lens produces very crisp and pleasing images, with an extremely smooth bokeh effect enhanced by the wide apertures available and the virtually circular aperture. Distortion measure at -2.1% barrelling, noticeable but correctable in software. It errs on the right side of things as we tend to accept some barrel distortion in wide angle lenses.  

In terms of sharpness, when we look at the central performance this lens is head and shoulders above the norm for ultra-fast manual focus primes. Even at f/1.2 sharpness is good and by f/2 is snaps into place and is excellent. From f/2.8 to f/5.6 central performance is outstanding, remaining excellent as we move from f/8 to f/11. Results are still very good at f/22.

The edges do not match the centre, being quite soft from f/1.2 through to f/5.6, just a fair performance. Sharpness however becomes good at f/8, very good at f/11 and is still very good at f/22.

If fine detail at the edges is required, then stopping down to f/8 to f/11 would be the best option, with a peak at f/11. The edges are relatively soft at the other apertures, yielding fair results. Best results are to be had between f/2 and f/11 if the main subject is central, and here the end result will be superb as the central sharpness is very impressive indeed.

MTF

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 Sony Alpha A7R II using Imatest.

CA (chromatic aberration) is quite noticeable at the edges, being over 2 pixels wide. Again we can look to software to reduce this when required. At the centre though, correction is approaching perfect, being less than one third of a pixel wide at most apertures.

CA

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 Sony Alpha A7R II using Imatest.

The Achilles heel of the lens, its weakest point, is probably in terms of flare. It is quite susceptible, despite the fine lens hood. In quite a few images, even though the sun is well shielded, flare makes its way into the image area. So some caution is needed when shooting against the light.

DZOptics KERLEE 35mm f/1.2 Sample Photos

Value For Money

At the time of writing, no final price is set, but if we anticipate something around £450-485 ($629 US) then a comparison could be made between the Kerlee lens and the alternatives for the mounts it will be available in. For a start, there is no other 35mm f/1.2 lens for full frame, any other lenses having been for rangefinder cameras. So the nearest comparison is between this and the 35mm f/1.4 lenses.

The Sigma 35mm f/1.4 is priced at £599, the Canon EF 35mm f/1.4 L USM at £959, the Canon EF 35mm f/1.4 L II USM £1799, the Nikon 35mm f/1.4 G AF-S £1399 and the Sony 35mm f/1.4 G £1099. All these are AF lenses.

There is also the Samyang 35mm f/1.4 AS UMC manual focus lens at £349.

On this basis the Kerlee 35mm f/1.2 would be very good value, being also quite unique with its f/1.2 aperture. However, this is not a price written in stone, so we shall have to wait and see.

DZOptics Kerlee 35mm f/1.2 Verdict

This is a fine lens, well made, with outstanding central performance. It suffers at the edges, although to be fair, when not photographing lens charts, which are flat of course, the real world results are very satisfactory. Sharpness is not really the main drawback, just a tendency to flare and quite a bit of CA at the edges. The very bright f/1.2 aperture is unique and may well be very useful in low light and for shallow depth of field effects. The bokeh is lovely and smooth.

In summary, a lens that can be used to make beautiful images, but do watch that flare.

DZOptics Kerlee 35mm f/1.2 Pros

Outstanding central sharpness
Beautiful bokeh
Virtually no central CA
Unique bright f/1.2 aperture
Crisp and positive manual focusing
Well made

DZOptics Kerlee 35mm f/1.2 Cons

Can be soft at edges
High edge CA
Susceptible to flare

 

FEATURES
HANDLING
PERFORMANCE
VALUE FOR MONEY
VERDICT

With outstanding central sharpness and beautiful bokeh, the Kerlee 35mm f/1.2 is a lens with a unique bright f/1.2 aperture.

DZOptics KERLEE 35mm f/1.2 Specifications

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