Panasonic Leica Summilux 15mm f/1.7 review

 In March 2014, Panasonic officially announced a new lens designed for Micro 4/3 cameras in partnership with Leica: the Panasonic Leica DG Summilux 15mm f/1.7. Almost a wide-angle lens, it is the only prime lens in the Summilux range that doesn’t offer an f/1.4 aperture. Although we have been publishing Sony E-mount reviews recently, I thought it would be useful to review a few Micro 4/3 lenses before selling them. Please note that this lens can be mounted on both Panasonic and Olympus Micro 4/3 bodies, since the Micro 4/3 mount is shared by both brands, although a few restrictions, mentioned later, make it less suitable for Olympus bodies. Here is our full page covering all current Micro 4/3 cameras.

When I was using DSLR cameras, there was a clear weight and size difference between that gear and my Micro 4/3 setup. With Sony A7 mirrorless cameras, the size and weight gap between bodies has narrowed, and now that very compact, lightweight E-mount lenses are easier to find, the Micro 4/3 format feels a little less compelling to me, even if it is still interesting.

Here, I’ll review this Panasonic 15mm f/1.7 mounted on a Panasonic G90, a 20MP Micro 4/3 mirrorless camera. There will be very few brick walls or charts, which mainly serve to illustrate optical defects. Instead, I’ll be offering a more field-oriented review. On that note, I have also just published a full review of the Panasonic G90.

The images shown were shot in RAW and developed in DxO PhotoLab 5, using the standard color rendering profile with optical defect corrections enabled, except when those defects are being shown and in the gallery images.

Launched at around €600, this is not exactly what I would call an affordable lens, especially since it is “only” a 30mm full-frame equivalent with depth-of-field rendering closer to an f/3.5 lens (although the f/1.7 aperture still applies for exposure). Its price has not dropped much either, despite the lens now being more than ten years old. For example, you can find a “real” 35mm f/1.8 Samyang in E-mount for around €350 (I know, I bought one myself!).

The most obvious alternatives are the Olympus 17mm f/1.8 and Panasonic’s 14mm f/2.5 and 20mm f/1.7. The Panasonic 14mm and 20mm lenses were designed to be very light and, above all, extremely compact. They are what we call “pancake” lenses, and they are so small that they can almost be mistaken for body caps. In my opinion, the Olympus 17mm is the most direct comparison, and it costs less than the 15mm f/1.7.

This 15mm is a fairly special lens, designed for street photography, with a few features that are not that common in this format. Equivalent to 30mm on a full-frame sensor, it offers a fairly standard focal length, close to the 28mm and 35mm views often favored by street photographers. The maximum aperture is also fairly wide, although that is quite common on Micro 4/3 lenses, since the smaller sensor makes it possible to offer faster apertures without making the diaphragm too large at this type of focal length. Recent Panasonic and Olympus cameras generally benefit from in-body stabilization, and that helps you use slower shutter speeds while avoiding motion blur, limiting the need to raise the ISO and helping preserve image quality.

Panasonic’s partnership with Leica often results in very nice lenses. This 15mm benefits from a high-quality metal build, denser than plastic but still impressively lightweight. At only 115g, it will feel at home on just about any Micro 4/3 body.

The lens includes 3 aspherical elements and a nano coating to help deliver a high level of detail. Its 7-blade diaphragm naturally produces fairly round bokeh at wider apertures, but it quickly becomes more polygonal at medium apertures.

As with all Panasonic lenses made in partnership with Leica, it has an aperture ring. Be careful, though: it will not work if you mount the lens on an Olympus camera. In that case, you will have to change the aperture using the dial on the camera body, just as you would with any lens without an aperture ring. The ring clicks in 1/3 EV steps and is quite small, which is normal given the length of the lens, but it is pleasant to use.

The focus ring is not very large either, but it is smooth enough and easy to turn with one finger. There is also an AF/MF switch on the side. The lens hood is unusual too: it is rectangular, so it cannot be reversed to save space in your bag, but the cap can be attached both to the front of the lens and to the hood, which is quite convenient. Fitting both a focus ring and an aperture ring onto such a short lens is a challenge for the manufacturer, but also for the photographer. Even without particularly large fingers, it is easy to move one ring while trying to adjust the other. Personally, I ended up changing focus quite often while adjusting the aperture.

As a lens designed for reportage or street photography, the autofocus had to be responsive and, just as importantly, discreet. The AF reacts very quickly and quietly. In AF-S mode, focusing is fast and accurate. It is a real pleasure to walk through the street with this lens: you point, focus, and shoot in less than a second!

In AF-C mode, things are a little different, but the lens itself is not really to blame. It still acquires the subject quickly and quietly, but it starts pumping as soon as it has to track it. This comes from Panasonic’s autofocus system, which is limited to contrast detection. Although it works well for this type of technology, it still requires regular back-and-forth movements in front of and behind the subject. That does not necessarily prevent the camera from focusing correctly when you press the shutter, but it can be very distracting while shooting.

To sum up, if you want better AF tracking, this lens will work better on an Olympus camera with phase detection, such as the E-M5 III or the recent OM-1 Mark II, but you will have to give up changing the aperture with the lens ring. If you are not trying to track a specific subject, you can mount it on any compatible camera and it will be very effective.

Image quality is good, although the Leica name may lead you to expect a little more. The center is slightly soft before f/2.8, and the edges even more so, especially toward the corners. It is better to stop down to f/4 for the most consistent results. Diffraction starts to appear from f/8 and hurts sharpness at f/11, and even more at f/16. Even so, the overall image quality remains good enough in many situations. To get the most out of the 20MP sensor in recent Micro 4/3 cameras, however, it is better to stay between f/4 and f/5.6 in reportage-style conditions. If your subject is really centered, you can use a wider aperture, such as f/2.8.

Here is a photo of my test scene.

Here is a 100% crop from the center of my test image at different apertures. Just move your mouse over the different aperture values to change the image (it’s magic!).

The bokeh is not especially soft, and you need to be fairly close to your subject to get a pronounced blur and shallow depth of field. In that situation, however, it is still possible to separate your subject from the background quite nicely.

Distortion is very strong, so you will lose quite a bit around the edges after correction. Even so, the overall image quality remains good enough in many situations.

Vignetting is noticeable at full aperture, as expected, then decreases at f/2 and even more at f/2.8. After that, it remains fairly stable: slight, but still visible even at f/8.

Chromatic aberrations are very slight. I noticed a little purple fringing, especially near the edges on white objects. Nothing dramatic, since it can also be corrected in post-processing with software such as Lightroom or DxO PhotoLab, which I use. Here is the small amount that can be seen in a 100% crop.

Flare appears when you shoot toward the sun, but it is much less visible when the sun is outside the frame. The lens hood does not change the results much.

For astrophotography, coma is quite significant at full aperture, with stars becoming elongated and taking on little wing-like shapes. Stopping down to f/2 improves things very slightly, but the improvement is more noticeable at f/2.8. Keep in mind that this lens was not designed for this type of use.

Sunstars are well defined when the lens is stopped down to f/11. At wider apertures, even f/8, the rays are more diffuse.

Focus breathing is very slight. You can see the frame tightening a little, but it is almost imperceptible and really not very distracting.

I have already mentioned them above, and honestly, I do not know those other lenses well enough to give you a perfectly informed personal opinion. Still, I can summarize the reviews I have read:

• The Olympus 17mm f/1.8, probably its main competitor, does not seem to offer better image quality or faster AF, but it costs less and has similar physical characteristics to the 15mm.
• The Olympus 17mm f/1.2 is a much higher-end lens and delivers some of the best image quality available. It is one of the strongest options in Micro 4/3 at the moment. It is, however, much more expensive, larger, and heavier.
• The Panasonic 20mm f/1.7 is more compact, lighter, cheaper, and very good for what it offers. However, its AF seems to be much more erratic.
• There are also zoom lenses that cover the 15mm focal length. I will not mention them all, but Panasonic offers the 10-25mm f/1.7 and 12-35mm f/2.8, while Olympus offers the 12-40mm f/2.8 and 12-45mm f/4. All of these are fairly high-end lenses and deliver very good image quality. If you are looking for versatility and image quality, these zooms are all excellent choices. It all comes down to size, weight, and price, with the 10-25mm in particular being extremely expensive.

In short, Panasonic and Leica released a very nice lens. It is quite versatile, well designed, and pleasant to use for many types of shots. For around €550, you get a wide maximum aperture and very good AF, all in a high-quality barrel. That said, the price still feels a little high for an f/1.7 prime, especially when the Olympus 17mm f/1.8, which is also well designed, costs around €150 less and delivers more or less similar performance.

For even less, Panasonic’s 20mm f/1.7 will be even more discreet while still offering good image quality, but it will be much less responsive because of its somewhat outdated AF. If you are looking for a simple, practical lens, the 20mm will be the better choice. But if you like beautiful objects that say “I am a photographer,” this 15mm will feel worth its price.

As mentioned many times now, if you enjoyed our review, feel free to use the links in the article (or below) when buying. This supports our work and helps us create more articles like this one. Of course, it will not cost you anything extra.

I’ll see you soon for another Micro 4/3 review—there’s more to come. If you are looking for lenses, feel free to take a look at our article about the best Micro 4/3 lenses.

See you soon,

Written by Sylvain PONS

I've been passionate about photography since 2010, learning as I went along. Today, I dedicate myself to guiding others in their choice of camera gear and sharing a variety of tips to improve their photography skills.

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