Panasonic 25mm f1.7 vs Panasonic 20mm f1.7 II

# **Panasonic 25mm f1.7 vs Panasonic 20mm f1.7 II** Since I have two f1.7 Panasonic prime lenses I thought I would do a simple comparison between the two, even if the focal lengths are a little different. Not a scientific comparison or anything like that, just some simple tests and posting what I found. They are the pancake 20mm f1.7 II and the recently released 25mm f1.7. I’ve had the pancake for a while now which I love because of its size. I used it with my GH2 and GX1, and just recently I bought a GX8 and with it’s purchase I could get the 25mm lens for $99. It’s normal price is $250 USD. In Canada it is sold for $280 CAD. The 25mm it’s supposed to be a cheaper lens compared to the pancake which had a retail price of $399 USD. It is bigger and it’s made out of plastic (except for the mount). It gets even bigger with the included hood. Physically it looks more like the 25mm f1.4 Leica lens. The first thing I thought when I opened the box and grabbed the lens is that it felt extremely cheap, it had like a hollow feeling and to the touch the matte finish felt crappy. I actually had doubts about having bought it as soon as I touched it. But now that I have tested it I can see that it’s a great lens I’m really happy that I got it. Also the more I use it and the outside gets more worn out I think it doesn’t feel as cheap as when I took it out of the box. Just by looking at the specs you can see that two of the benefits that the 25mm has over the 20mm is that the 25mm can close all the way to f22 whereas the pancake only goes to f16. The 25mm supports continuous focus, the pancake does not. Both have a filter size of 46mm. The pancake is a little better at closeups, the minimum focus distance is of 0.25m, and the 25mm minimal focus distance is 0.20m. Neither of them have optical image stabilization. Here are some pictures of a guitar. Click on any of them to open a larger version. The camera is a little close for this one. I will shoot some outdoor pictures and post them later. I am using the pinpoint to autofocus on the first screw on the left side.

The first thing I noticed when I was comparing pictures is that the pancake lens has a magenta tint while the 25mm has a more greenish tint. I set the white balance to the same temperature on both and made sure in Adobe Camera Raw that the temperature were the same.

Also there’s pretty strong vignetting on both lenses when they are wide open. Here are some animated gifs.

Both lenses are pretty sharp, even wide open. The 25 appears to be sharper, though. In focus areas they are almost the same, but the pancake is a little softer. In the out-of-focus areas the 25mm is way sharper, you can tell on the bokeh how more defined it is.

If you see the strings of the guitar in the next image you will see how softer they look on the pancake, and how defined they look on the 25mm even when they are out of focus. A screw at the top of the guitar is creating a bigger and rounder bokeh on the 25mm one. Check also how the purple and green fringing look pretty much the same with both lenses. I’m focusing on the screw at the center and around that area both look the same in terms of sharpness.

The 25mm seems to achieve a shallower depth of field than the pancake. When compared side by side (or top and bottom, rather) you can see that the 25mm closed to f2.5 somewhat matches the pancake closed at f1.7. I guess it could be because of the difference in field of view. This means that if you crop a picture taken with the pancake to achieve a similar field of view to the 25mm you will end up with less bokeh.

Here is another bokeh test (these pictures are not crops, I’m just really close to the subject). With the 25mm I focused as close as the lens would go and then I moved the camera close to a lightbulb until it was in focus. Then with the 20mm with the same camera position I focused on the lightbulb. Then for the third picture, with the 20mm I focused as close as the lens would allow and then moved the camera again closer to the lightbulb until it was in focus (the pancake can focus closer so I was able to get closer to the lighbulb than with the 25mm). This way you can see the biggest size the bokeh can get with both lenses. Bokeh still looks bigger with the 25mm.

For video neither are good when manual focusing since they have electronic wired focus. The 25mm is a little better when manual focusing since it’s bigger than the pacake. It’s easier to grab and rotate the focus ring, and it feels very nice and smooth. Both are pretty silent when focusing but the 25mm beats the pancake in low noise. The 25mm is a little quieter when focusing. Here’s a test video where I’m using the GX8’s “Snap Movie” mode and setting two focus points so that the camera does the rack focus by itself. Then I’m doing another test where I’m using the touchscreen to “manually” focus on a different plane. I boosted the audio to make the focus noise more noticeable, if it’s still not loud enough just increase the volume on your speakers.

When using the “snap movie” the pancake did the rack focus faster because the two focus planes where closer to each other because of the wider field of view of the lens. But still it is a little louder than the 25mm. For the manual touch focus test you can see how the pancake hunts for the focus making it look electronic. The 25mm is smoother but a little steppy, you can even hear the motor moving in little steps. I don’t know if the problem with the pancake focusing that way is because it lacks C-AF.

For pictures the 25mm is just way way faster than the pancake when focusing, I think as fast as the pancake 14mm f2.5.

Both lenses seem to have pretty similar chromatic aberrations. Purple and green fringing look pretty much the same on both.

I will post more test pictures and videos soon. But for now I can say that I really recommend buying this lens. If you are looking for something really compact then the pancake is a great option but if you don’t mind the size and the smaller field of view, I can say that the 25mm is a better option than the pancake. It’s cheaper, sharper and focuses way faster and more quietly.