The unique selling point of the Leica DL8 and its
precursors, the DL7, LX100 and LX100.2
is the Leica DC Vario-Summilux f1.7-2.8, 10.9-34mm Asph zoom lens.
Designed by Leica in collaboration with Panasonic, the lens
first appeared on the LX100 in 2014. With a focal length range of 10.9-34mm, it
covers an image circle of 19.2mm on a standard 4/3 sensor which has a diagonal
of 21.6mm. As there is no lens mount and no focal plane shutter, the rear
element of the lens can be placed very close to the sensor. These design
features enable the lens to have an unusually small f-number range of 1.7-2.8
and the camera to have a multi-aspect ratio feature in which 4:3, 3:2 and 16:9
ratios all have the same effective 19.2mm diagonal on the sensor.
These two features continue a theme which has characterised
PanaLumix and Leica D-Lux models for almost 20 years. Prior to 2014 smaller
sensors were used, making the lens designers task a bit easier but lacking the
image quality of the 4/3 sensor.
I am a long time user of these cameras. I bought the LX100,
LX100.2 and D-Lux 7 as each came onto the market and took them around Australia
and several other countries including Iceland.
I experienced two problems with each of these cameras. The
first is unreliable autofocus in low light and when the camera is presented
with bright specular highlights. The
second is inconsistent lens sharpness. Each of my cameras suffered from
problematic softness in some or several parts of the zoom range and some or
several parts of the image frame. This was frustrating to put it mildly
especially as nobody else seemed to be reporting these problems.
So it was with some trepidation that I decided to get the
DL8.
As to the autofocus I have to report that while the DL8 is
more reliable than previous models, it is not perfect and in the course of a
photo session I still see several mis- focussed frames in low light and when
there are bright or specular highlights under the AF area.
The lens has provided a more positive experience. My copy of
the DL8 lens has no obvious faults. It is well centered throughout the zoom
range. It is consistently sharp in a large central area of the frame at all
focal lengths with evenly distributed mild softness in the periphery most
noticeable at the wide end of the zoom range.
The optimum aperture for sharpness is f5.6 at all focal
lengths.
I suspect that
problems with the lenses on my previous cameras are related to quality
control not design. Both Panasonic and Leica have been a bit coy about revealing
the design details of the lens but as described in the DPR review of the LX100
in 2024, it appears to have 10 elements in 6 groups, with each group being able
to move separately during zooming. In addition the lens has a double extending
barrel design which sees it almost triple in length from 27mm at 10.9mm focal
length to 80mm at a 34mm focal length.
So we have a lot of parts moving in complex fashion and a
requirement that each of those parts must be located with near-microscopic
accuracy for the lens to perform as designed.
My guess is that Leica might have spent more resources on
lens construction and quality control for the DL8 than has been the case with
the three previous models which use this lens.
So I subjected the lens on my DL8 to more rigorous testing than usual. I photographed my usual test chart, pointed it at the sun and gave it many different and challenging types of subject to reproduce. I also compared it to several other lenses in my ongoing investigation of compact cameras from different brands.
My overall impressions of the lens are positive. It is
entirely usable at the widest aperture at each focal length.
Optically my copy is very good to excellent at focal lengths
of 35-75mm (FFE) and good to very good at 24-28mm (FFE) focal lengths.
Resistance to flare from the sun in or just outside the
frame is very good. I can induce a bit of veiling and color flare with the sun
in the right location but in most situations sun flares are not a problem.
The lens/sensor/processor combination is prone to color fringing in some situations.
With the aperture at or near the widest available and the focal length towards
the wide end of the zoom I frequently see red color fringing around bright
highlights. I notice this quite often indoors with bright sources of artificial
light. This is difficult to correct and is different from the blue/green color
fringing which I see on high contrast edges such as foliage against a hot sky
outdoors.
The built-in profile corrects Raw files well for distortion and peripheral shading.
The image stabiliser works well, allowing slow speed hand
held photos indoors if desired.
Single shot autofocus is fast and usually but not always
accurate. Dark subjects with a bright background and bright or specular
highlights under the AF area box can produce misfocussed frames. We need to be
aware of this when using the camera and check focus to see if a re-shoot is
required.
The lens can focus very close but only at the wide end of
the zoom, with the front element almost
touching the subject at 24-28mm (FFE). This limits the lens’ usefulness for
macro work but can be handy for occasional close-ups when a macro lens is not available.
I include here the issue of moiree although it is not a lens
problem but a phenomenon seen with some cameras which lack or have a weak
anti-aliasing filter on the sensor. I noticed when testing that fine print on
my test chart is reproduced by the DL8 with false color moiree and lorikeet
(bird) feathers are reproduced with a false pattern. I have not seen the
problem in general photography but it can occur whenever the regular pattern of
a subject generates interference with the regular pattern of the Bayer filter
array on the sensor.
I assume the DL8 has no AA filter or a very weak one.
This does enhance the ability of the camera to reproduce
fine subject details but also increases
the risk of moiree.
Comparisons
I have been running a multi-camera comparison between the
DL8, Lumix G100 with Lumix 12-32mm f3.5-5.6 and Canon R50 and Canon R10, each with the Canon
RF-S 18-45mm f4.5-6.3. The DL8 has the obvious advantage of a 2-2.5 stop wider
aperture than the kit lenses, but when compared at the same apertures and
output size there is very little difference between them although on my tests
the kit lenses are marginally sharper with less color fringing. Even the much
derided Canon RF-S 18-45mm is actually very good within the constraints of its
focal length and aperture range.
A few years ago low f-stop numbers would have given the DL8
a big advantage as it can usually operate at a wider aperture and therefore
lower ISO sensitivity setting producing less noise than cameras with small
aperture kit lenses.
But noise reduction using artificial intelligence has
changed the game. With Adobe>Enhance>Denoise AI I am now getting clean, sharp results from
the crop sensor Canons and the Lumix G100 at ISO 12800.
Summary
The lens is the most distinctive feature of the Leica DL8
and one of the more interesting consumer camera lenses to have been produced
over the last 20 years or so. It is very
good but not perfect although I think we can probably agree that perfect is the
enemy of good.
It allows the DL8 to be used at low ISO sensitivity settings
indoors and permits greater foreground<>background separation than is
possible with kit zoom lenses.
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