A cheap, bright, f/1.7, standard lens has been one of the last gaps in the extensive range of Panasonic micro-43 lenses. That is less strange than it seems, because Panasonic already has two lenses in this range. On the one hand, you can choose from the Panasonic 20 mm f/1.7 II ASPH LUMIX G pancake lens, which is cheap, super small and light. On the other hand, there is the Panasonic Leica 25 mm f/1.4, which - certainly considering the high f/1.4 brightness - is certainly not expensive and offers very high image quality. I can hear you thinking, "Then why a Panasonic 25mm f/1.7?" That is because there is a considerable space between the bright 25 mm and the pancake 20 mm in terms of price, dimensions and image quality. And the Panasonic Lumix G 25mm f/1.7 fills that gap perfectly.
25mm offers a field of view with a human perspective f/1.7 offers the possibility of playing with depth of field and bokeh
The Panasonic Lumix G 25 mm f/1.7 has a 25 mm focal length. On a micro-43 camera, that corresponds in terms of field of view to a 50-mm standard lens on a camera with a full-frame sensor. That is a field of view that roughly corresponds to what the human eye can see sharply and what we therefore perceive as somewhat normal. In terms of exposure, the Panasonic 25 mm f/1.7 corresponds to a 50-mm f/1.7 on a camera with a full-frame sensor. For the depth of field, you have to double the aperture number, and it corresponds to a 50 mm f/3.5. Some find the latter a disadvantage, because you get less bokeh, less blur in the background when you take a portrait. This may also be an advantage. With a comparable 50 mm f/1.7 on a full-frame camera, you do not even get the entire face sharp at one time at full aperture for a portrait. In low light, if you have to use the largest aperture, with the Panasonic Lumix G 25 mm f/1.7 at full aperture, you get more depth of field, and you can, for example, make a double portrait of two people much more easily. The 25mm focal length of the Lumix G gives a completely natural perspective. That means that you have a lot of flexibility, and the lens does not force itself on you with wide-angle or telephoto effects. It also means that you must ensure that the image you create is interesting enough. An important reason why these types of "standard" lenses have always been so popular is that they offered high image quality and brightness for a relatively low price. An equally bright and good wide-angle or telephoto is generally just a bit more difficult to make. And that is apparent with the Panasonic Lumix G 25mm f/1.7. The lens is very cheap if you look at the almost flawless image quality that you get in return.
BUILD AND autofocus
The housing of the Panasonic Lumix G 25 mm f/1.7 is almost entirely made of plastic. That makes the lens nice and light (125 grams) and ensures that it does not feel cold even in the winter when you work with this lens. For lenses as compact as this 25 mm, the use of plastic is in our opinion simply better than metal. If you accidentally drop a lens like this, the low weight means that you will rarely have any damage. You don't get dents in plastic, and to crack it, you have to drop it from much higher than normally possible. The 25 mm f/1.7 is 52 mm long, almost 61 mm in diameter, and the filter mount is 46 mm. The lens has seven aperture blades and uses two aspherical lenses and a lens that consists of glass with an ultra-high refractive index to prevent color errors. For a lens in this price range, that is pretty impressive. The Lumix G 25 mm f/1.7 also scores well on autofocus. In comparison with older Panasonic lenses, the AF speed has increased. The noise that the camera and the stepper motor make in the lens during focusing has been reduced to virtually zero. The Panasonic 25 mm f/1.7 communicates with the camera 240 times per second while focusing using the Contrast AF and DFD (Depth from Defocus). This makes the Panasonic 25 mm f/1.7 quieter and faster than almost all lenses from other brands, but also faster than, for example, the Panasonic 20 mm f/1.7 II ASPH LUMIX G pancake or the Panasonic Leica 25 mm f/1.4. That also contributes to the universal usability of this lens. The shortest focusing distance is 0.25 meters, and the maximum magnification is 0.17x. It is therefore not a macro lens. If you compare it with a full-frame camera, the magnification measure is 0.35x. And that is actually quite good. So you can still photograph pretty small subjects with this lens.
The Panasonic Lumix G 25 mm f/1.7 delivers good sharpness even at full aperture. The center is slightly sharper than the corners, but the difference is less than with the Lumix 20mm f/1.7 pancake, for example. Stopping down to f/2.8 causes a small increase in sharpness in the center and a clear improvement of the corners. They are then almost equivalent to the center of the image. Another stop further, at f/4, this lens reaches its maximum quality. That sharpness at f/5.6 is just as good, and then it slowly decreases, although f/8 and f/11 are still perfectly usable if you need the extra depth of field. What is striking about the entire range is that the sharpness is nicely evenly distributed over the entire image field, apart from at the largest aperture. The 25 mm f/1.7 scores clearly better in that than the smaller 20 mm f/1.7.
VIGNETTING AND DISTORTION
Distortion is something that you don't have to worry about for lenses with mirrorless cameras, because this is already corrected in the camera, and you will therefore never actually see any of it in practice. However, some wide-angle lenses for mirrorless cameras have such high distortion that correcting it comes at the expense of the sharpness on the edge of the image. That is why it is something that we continue to test. In uncorrected RAW files, the Panasonic Lumix G 25m f/1.7 shows that it is not completely free of distortion. That is then 1.5 percent barrel-shaped. The camera corrects that to almost 0%. That is why there is actually none of it to see in the jpeg graph. That the correction of the distortion in this case is hardly at the expense of the sharpness is clear from the resolution graphs above.
Bright lenses generally always suffer from vignetting in the corners at full aperture, and the Lumix G 25m f/1.7 is no exception. In RAW, it is 1.6 stops at f/1.7, and you could see that in practice. However, this vignetting is reduced in the camera to 0.6 stops and even 0.2 stops at f/2.8. Those are values that you will no longer see in the photos and that are therefore not important in practice. The Lumix G 25m f/1.7 thus performs really well on all the important points.
Curious about the performance of the Panasonic Lumix G 25 mm f/1.7 in practice? Click on the button below and visit our renewed web gallery with practice shots. The images can be downloaded in full resolution to be viewed at 100%.
WYSIWYG score: This table shows the performance of this lens if you save the files in the camera as jpg, with all available in-camera lens corrections applied. This score gives you for this lens/test camera combination: "What you see is what you get".
Focal Length mm @ FF Total score Resolution lat. C.A. Vignetting Distortion AF accur. AF speed
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 use lens correction profiles in Photoshop or Lightroom to convert RAW files, then the RAW scores for distortion, vignetting and chromatic aberration are even better.
Focal Length mm @ FF Total score Resolution lat. C.A. Vignetting Distortion AF accur. AF speed
Image quality: approaches the Panasonic Leica 25mm f/1.4
Sensitive to backlight (so use the included lens hood)
No built-in image stabilization (luckily modern cameras from both Panasonic and Olympus have in-body image stabilization)
Invest in a bright standard lens like the Panasonic Lumix 25mm f/1.7. It's not expensive, and you will enjoy it for a long time.
We wondered how the Panasonic would distinguish itself from the Panasonic 20 mm f/1.7. The answer to this is twofold: to begin with, the AF is quieter and faster. And on top of that, the sharpness to the corners is better. So there is less gradient in sharpness than with the 20 mm. On the other hand, the 25 mm f/1.7 is bigger than the 20 mm f/1.7. It's a matter of taste, whichever you prefer. If you want to put the camera in your pocket, choose the 20 mm f/1.7. If you're planning to focus manually more often, then you'll probably like the larger 25 mm f/1.7 better. The difference in field of view between 25 mm and 20 mm will not be an issue for most photographers: it's small, and you get used to it, since that's what you chose one of the two Lumix alternatives for. How does the Panasonic 25 mm f/1.7 compare to the older, lighter and more expensive Panasonic Leica 25 mm f/1.4? Again, the AF of the 25 mm f/1.7 is quieter and faster (although we have no measurement results for the 25 mm f/1.4). There are no shocking differences with regard to image quality, weight and dimensions. The 25 mm f/1.4 wins in terms of image quality and bokeh over the 25 mm f/1.7. However, it has a retail price that is approximately 2.5 times as high as that of the 25 mm f/1.7. The Panasonic 25 mm f/1.7 is, in short, an attractively priced standard lens with good build and image quality, which a starting photographer can enjoy.
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.