Design and buildThe Panasonic Leica DG Summilux 25mm f1.4 lens is a well built and sturdy lens. It's the equivalent of a 50mm focal length on micro four thirds cameras.
Compared to the Panasonic 20mm f/1.7 lens, this is twice as heavy at 200g, and twice as tall. It has a nice weight, but not heavy to tilt the camera (GF1) forward.
The build and construction quality is similar to the Panasonic 45mm f/2.8 lens, after all they share the same Leica branding.
The manual focusing wheel is nicely-damped, even smoother than the 20mm lens. The groove is rubber and collects dust easily.
There's no optical image stabilization.
The filter thread is 46mm so you can add on stuff like the lens hood, should you not like the default plastic lens hood provided.
AutofocusAutofocus is almost instantaneous. The front lens element is fixed, and the focusing is internal.
Operating noise is minimal and can't be picked up by the camera's mic.
Autofocus during movie mode isn't that fast but it's not just this lens. Manual focus is focus-by-wire and it's a pleasure to focus with the responsive focus ring.
Below's a set of photos to look at the sharpness. On the left is from a bottom corner edge. On the right is the centre. The photos are taken on a GH2 with a remote.
Centre sharpness is optimal around f/2.8, corner sharpness at f/4.
Below's a comparison of corner sharpness between the Panasonic lens compares with with the Voigtlander Nokton 25mm f/0.95.
Corners for the Nokton 25mm is never sharp and only gets better at f/8.
Chromatic aberration comes in the form of purple fringing at f/1.4 and f/2. Interesting, subjects that are in focus show more purple fringing.
DistortionThere's no discernible distortion.
VignettingThere's vignetting at f/1.4 that becomes barely noticeable at f/2.8.
BokehThe bokeh is creamy. It probably has the best bokeh compared with other lens.
It has a shallower depth of field than the 20mm lens. If you can get the subject isolation and bokeh right, there's often a 3D feel to the photos.
In the photo above, I wasn't quite close to the guy, but you can still get a bit of a background blur.
I would highly recommend getting a ND filter if you want to shoot wide open at f/1.4. I've a Hoya 4X ND filter that I use frequently outdoors. The ND filter enables you to shoot at wide apertures to create the bokeh, while preventing over exposure.
Lens flareIn the right conditions, there's flare, but rare. The lens has a Nano Surface Coating to reduce flare.
Anyway, you can always use the lens hood provided. I find that lens hood a bit too big so the non-vented metal one below is what I'm using. It looks more streamlined than the vented hood from the 20mm lens. The hood doesn't not cause additional vignetting.
VideoThis is a video shot with the lens on a GH2. There's a bit of underexposure and I blame that on my skill. I've used a ND filter at several occasion, maybe that explains why.
The lens is quiet and great at shooting videos. The f/1.4 and its equivalent bokeh can really be useful in isolating subjects.
Other things to noteOne minor downside is the minimum focus distance of 30cm, compared to the 20mm lens' 20cm or the Nokton's 17cm.
QuirksThis lens can be noisy when used on Olympus cameras. The noise is caused by aperture blades opening and closing. On Olympus cameras, to achieve a consistent exposure, it constantly adjusts the aperture size and that produces the noise.
On Panasonic cameras, the lens works silently. To get that noise, you have to press the Shutter Speed Effect button and adjust the aperture sizes manually.
Compared to the Panasonic 20mm f/1.7f/1.4 vs f1/7 is about two thirds stop of a difference. That's minor difference but sometimes matters.
The 20mm is smaller and lighter. The 20mm is wider and more flexible in the sense that you can get the 25mm field of view by just cropping (unless you follow the code of thou-shall-not-crop). To get the same view, you don't have to crop much, and you don't have to walk much also.
The sharpness of both lens are comparable, probably only discernible only to the most observant eyes.
The main difference is the bokeh. The 20mm lens has a slightly harsh bokeh compared to the beautiful creamy one from the 25mm lens.
If you already have the 20mm lens, it might not be worthwhile to get a new (pricey) lens for the bokeh.
Compared to the Voigtlander Nokton 25mm f/0.95The Nokton lens is two times heavier, 410g vs 200g. It's longer, 70mm vs 54.5mm. The build is excellent and looking through all that glass can be mesmerizing (intangible).
The Nokton is a manual focus lens which takes some time getting use to it. Auto-focus is more convenient I must say, seeing that I'm already spoiled by auto-focus.
The aperture ring on this big guy which means you can change your aperture while shooting videos. Manual focus is useful for shooting videos. Using manual focus is generally faster (for video) and you can always be sure you're focusing on the right subject - there's not going to be any auto-focus hunting. Big advantage if you require that change of depth of field from shallow to deep.
For bokeh, both are quite evenly matched.
The Nokton has a 1 stop advantage which can mean the difference of getting or not getting a shot during low light. However, shooting at f/0.95 comes at a cost of a slightly hazy image (some prefer to call it a glow).
I typically use the Nokton at f/1.4. Centre sharpness improves dramatically when stopped here. At deep focus, the corners aren't particularly sharp. This lens just isn't as good at corners. But for my purposes, which involves posting photos to the web, it's not a big issue. If you're printing, then, yes, you should check out more sample images.
If don't already have any 50mm equivalent lens, I would recommend the Panasonic one. It's smaller, lighter and the auto-focus is really convenient.
Conclusion and who this lens is for
The main consideration when getting this lens is, well, it's effectively 50mm. Shooting with this lens made me realise my preferred focal length is actually from 24-35mm.
I'm using the 25mm lens primarily outdoors and in open spaces. I've used it at exhibitions and the focal length was quite limiting for that sort of situations - I had to change to 24mm to be able to capture more of the scene. For shooting indoors, it's better to get a 28mm or wider.
This lens is an amazing low light performer. The large aperture ensures it has no problem focusing in low light, and you're only limited by the autofocus capabilities of your camera.
The lens is pricey but the image quality it delivers matches the price.
At a glance
+ Well built, sturdy
+ Nice weight
+ Silent and fast focus
+ Large aperture, great for low light shooting
+ Excellent image quality
+ Beautiful creamy bokeh
+ Good centre sharpness
+ Comes with lens hood and pouch
- Edge softness when shooting wide open
- Vignetting at wide open
- Chromatic aberration not corrected on Olympus body
AvailabilityPanasonic Leica DG Summilux 25mm f/1.4 lens is available on Amazon (US | UK | DE | FR | IT | JP)
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