If you’re an m43 gearhead geek, you will love this article by Roger Cicala at Lens Rentals. But if you’re not an m43 geerhead geek, I recommend just skipping this post.
What I found interesting is that the Panasonic 25mm f/1.4 has a lot of sample variation, and I think I’ve encountered this problem with other Panasonic lenses. I have a 14mm f/2.5 lens, and the performance is pretty disappointing, but other people on the internet insist it’s a great lens, so I assume I have a bad copy. On the other hand, my 25mm f/1.4 is quite sharp, so I guess I lucked out with that lens.
Another reason I tend to avoid Panasonic lenses is because they cause more fringing, especially on Olympus cameras. For example, when I used the 25mm f/1.4 outdoors, wide open, I saw purple haze around bright objects in the photo. I’ve also encountered other weird fringing with the Panasonic 25mm f/1.4 that didn’t correct well with the tools available in Adobe Camera Raw. Unfortunately, this is a lens flaw that Roger Cicala doesn’t test for.
Regarding the Olympus lens, Roger Cicala noted that the lens has field curvature, and this is something that affects all of the Olympus 1.8/2.0 primes. Don’t expect to take a picture of a brick wall with these lenses wide open and see sharp bricks in the corners.
Roger Cicala also noted the significant sample variation for the 25mm f/1.8 at the corners. That’s another problem that I’ve noticed that afflicts the Olympus prime lenses. There are a lot of de-centered lenses, where you have one side or corner that’s more out of focus.
Roger Cicala didn’t compare the 25mm f/1.8 to the 25mm f/1.2 when both were at f/1.8. They are both pretty similar at f/2.8, and the f/1.8 is quite a bit sharper at f/1.8 than the f/1.2 lens is either at f/1.4 or f/1.2.
In my opinion, the conclusion from the tests are as follows:
1. The f/1.8 is the sharpest lens wide open, and that’s the lens to buy if you don’t need an aperture wider than f/1.8. Especially if you have an Olympus camera, because I don’t think that Panasonic lenses work as well on Olympus cameras.
2. If you do buy the f/1.8, make sure you test it for de-centering and buy it from a place where you can return/exchange it if you feel you have an especially bad copy (but be realistic, don’t expect perfection centering).
3. The f/1.2 is a pretty good lens if you desire something faster than f/1.8 and you can afford it. And you don’t mind the size and weight. I don’t see myself buying one in the future; I rarely use the 25mm lenses that I already own.
The current price for the f/1.8 is $324, which is the least expensive of the lenses tested, but that’s still a lot of money for a normal prime lens of only a modest f/1.8 aperture. I suspect that Olympus (and Panasonic) have a very high profit margin on these lenses.
I don’t shoot that often at 25mm (which is approximately equivalent to 50mm on full frame), but it would be a great focal length for taking flattering pictures of yourself to post on social media. Wider-than-normal lenses produce unflattering distortion, while longer-than-normal lenses look like your trying too hard.