What does the Panasonic 42.5 mm f/1.7 portrait lens have to offer? The Panasonic 42.5 mm f/1.2 Noctilux is brighter, has the same focal distance and is, where build and image quality are concerned, perhaps the best micro-43 lens of today. But it is also the most expensive. If you are searching for a less expensive alternative for making great portraits, with which you can also isolate the subject from the background, then you'll do well with the much less expensive Olympus 45 mm f/1.8, which offers an exceptional level of quality for its relatively low price. What does the Panasonic 42.5 mm f/1.7 have that those other two do not?
Panasonic 42.5 mm f/1.7? Surprise!
I suspect that at the Panasonic design table, they expressed the desire to design a lens with a higher image quality than the Olympus 45 mm f/1.8 (and that would not be easy), and at the same time, with a remarkably lower price than the Panasonic 42.5 mm f/1.2. The Panasonic Lumix G 42.5 mm f/1.7 Asph is indeed bright. And the focal distance is perfectly suited for making portraits. But does the Panasonic 42.5 mm f/1.7 fulfill the imaginary ideal?
Build and auto focus
The Panasonic 42.5 mm has a metal mount and a lens body with a matte black metallic finish. The lens is so light that I'm not certain whether it's really metal. But in any case it's solidly built and beautiful. AF is lightning fast and silent. The focus ring for manual focusing is sufficiently broad and turns smoothly. The focus system is electronic, so that there is no hard stop at infinity or at the shortest distance. The front lens does not turn during focusing, which is nice for the use of a circular polarization filter or a grayscale filter.
The optical design consists of 8 lenses in 8 groups and includes an aspherical lens element for the reduction of chromatic aberrations and distortions. In addition, the aspherical lens element optimizes the clarity and the colors. A number of accessories (sun cap, lens caps and storage bag) are included. Panasonic gives a two-year guarantee for this lens.
No photographer is able to keep his or her hands perfectly still. At shutter times longer than 1/100 of a second (indoor shots, or shots in low light), you can use the built-in optical image stabilization (POWER O.I.S.) in order to compensate for vibrations, for the sharpest possible result. Power OIS is particularly interesting for owners of a Panasonic camera, since Olympus cameras are equipped with effective in-camera image stabilization.
Vignetting is actually not present. At full aperture, you might recognize the half stop of vignetting in critical situations (blue skies during a sunny vacation, or a small bit of cat's eye bokeh in the corners of night shots made at full aperture) if you process your RAW files with 3rd party RAW converters, but otherwise, you won't. The Panasonic 42.5 mm Nocticron, the Olympus 45 mm f/1.8 and this new Olympus 42.5 mm f/1.7 all perform ideally on this point. The Panasonic 42.5 mm f/1.7 even does a bit better than the Nocticron, which you can primarily recognize from the cat's eyes in the corners.
The lens design assumes visible (1.7%) barrel-shaped distortion, but in the jpg files or the RAW files that you open in Silkypix, Lightroom or Photoshop, it can't be seen. This is the explanation for the lower scores for RAW files without lens corrections for this lens in comparison with the Olympus 45 mm f/1.8 and the Olympus 42.5 mm f/1.2 Nocticron. Correction for this distortion has no negative effect on the final image quality, since the end score for this lens, including all lens corrections (SPOILER ALERT) is nearly as high as that of the Nocticron.
Bokeh at a short focal distance If you use a lens with a focal distance lower than 50 mm, then it becomes more difficult to get a small focal depth. Even so, with this lens, you can create a very nice background blur, as long as you creep up close to your subject.
It's advisable to actually use the included sun cap—first for the protection of the front lens from damage, but perhaps even more importantly, to combat the flare (at the top of the image in the practice shot shown here) and ghosts (the purple, aperture-shaped fleck) that can occur with bright backlighting. Nobody's perfect.
The center sharpness at full aperture is nearly optimal, but in our measurements it increases a bit more after stopping down 1 stop. In practice, you will not notice that sharpness difference in practice. The sharpness at the edges at full aperture is visibly less high than in the center—although certainly not bad—and increases. At f/4, you see no difference in sharpness any longer between the center and corners. Where sharpness is concerned, the Panasonic Nocticron (highest center sharpness), Olympus 45 mm f/1.8 and the Panasonic 42.5 mm f/1.7 (a bit better in the corners before correction for distortion, but a bit less than the other two after correction for distortion) differ little from each other.
The MTF50 was tested by setting the image ratio of the test camera to 2:3, so that the measurement results can be directly compared with the measurements results of lenses on a camera with an APS-C or full-frame sensor. If you use the camera in the standard ratio of 4:3, the number of lines per image height is higher.
Lateral chromatic aberration, red and blue edges at sharp contrast transitions in the corners of the image, is not found with this lens. In the measurement results, the lateral chromatic aberration was the highest at the smallest apertures (f/11), but in the practice shots, I never came across lateral chromatic aberration with this lens. Bright (<f/2.8) lenses tend to have trouble with longitudinal chromatic aberration: purple edges in front of the focal point and green ones behind it. This is also called color bokeh. As you can see in the practice shot above, the Panasonic 42.5 mm f/1.7, just like the Nocticron and the Olympus 45 mm f/1.8, is not completely free of color bokeh. But the phenomenon is well suppressed and actually never disturbing present.
Bokeh: Panasonic 42.5 mm f/1.7 vs 42.5 mm f/1.2
The aperture of the Panasonic Lumix G 42.5 mm f/1.7 is constructed of seven rounded blades for a soft and natural rendering of blurred parts in a shot. You thus place the attention fully on the subject and any disruptive items in the background are nicely blurred. Above, we have made a comparison of the bokeh of the Panasonic 42.5 mm f/1.2 Nocticron with the bokeh of the Panasonic 42.5 mm f/1.7. Not bad, eh? OK. The Nocticron bokeh is nicer, but shows a bit more cat's eye character due to a tiny bit more vignetting at full aperture. With a better model, fantastic portraits can be made with this attractively priced lens.
"Color bokeh": almost no bright lens can avoid it.
Conclusion Panasonic 42.5 mm f/1.7 review with Olympus OM-D E-M1
Look in our list of reviewed lenses or in our list of reviewed micro-43 lenses in order to compare the performance of this lens with that of other lenses.
WYSIWYG score: This table shows the performance of this lens if you store the files in the camera as jpg, where you have applied all available in-camera lens corrections. This score gives you for this lens/test camera combination: "What you see is what you get".
Pure RAW score: This table shows the performance of this lens if the file is stored in the camera in RAW format. This score approaches the intrinsic quality of the combination of lens and test camera. If you make use of Photoshop, Lightroom or SilkyPix for the conversion of RAW files, then the RAW scores are the same as the jpg scores.
Without correction, visible distortion in RAW files with 3rd party RAW converters
Too long, didn't read (TL/DR)? As far as price, build and image quality are concerned, the Panasonic 42.5 mm f/1.7 lands between the Olympus 45 mm f/1.8 and the Panasonic 42.5 mm f/1.2 in. Good luck/enjoy when making a choice!
Panasonic rather unexpectedly released a 30 mm macro lens and this 42.5 mm f/1.7 portrait lens. There was also not much of a fuss made about these lenses, and with that Panasonic has done these lens a disservice. In an earlier review, the Panasonic 30 mm macro showed very good test results. With the Panasonic 42.5 mm f/1.7, the story is really no different. The build and image quality of this lens is perfect. In comparison with the Panasonic 42.5 mm f/1.2 Nocticron, this lens is much more compact and lighter. In comparison with the Olympus 45 mm f/1.8, the Panasonic 42.5 mm f/1.7 performed a bit better. A part of the higher price of the Panasonic in comparison with the Olympus is caused by the built-in image stabilization (which the Olympus does not have), but the finish level of the Panasonic 42.5 mm f/1.7 also seems to me to be a bit higher. The designers from Panasonic had no small challenge in the design of this lens, but as far as I'm concerned, they did themselves proud.
Author: Ivo Freriks
With Camera Review Stuff I hope to make a modest contribution to the pleasure that you get from photography. By testing cameras and lenses in the same way, evluating the results and weighing up the pros and cons, I hope to help you find the right camera or lens.