I made a number of comparisons with the Olympus 7-14mm f2.8 and Lumix G 7-14mm f4 both inside and out to evaluate their quality. I’ll start with an outdoor comparison taken from Brighton Pier, with the camera tilted so the natural horizon stretches from corner to corner, ensuring plenty of fine details in the hardest areas for the lenses to render sharply.
I shot the scene with both lenses at 7, 10 and 14mm and at every aperture setting using an Olympus OMD EM1 and made a series of crops from the corner and center. I’ll start with the widest coverage with the lenses set to 7mm, and as always the cropped areas are indicated by the red rectangles here. I’ve presented these crops below at 100%, starting with the Olympus 7-14mm at 7mm f2.8, f4 and f5.6. These are all JPEGs out of camera.
The most striking thing about the crops above is just how well the Olympus 7-14mm performs across the entire frame, delivering sharp details right into the corners even when the aperture is wide-open at f2.8. The crops also seem bereft of vignetting or chromatic aberrations, even on the RAW files with corrections disabled. A superb start for the Olympus 7-14mm f2.8, but how does the Lumix G 7-14mm f4 compare? Here’s how that lens looks at 7mm f4 and f5.6.
Above you can see the Lumix G 7-14mm is also capable of delivering plenty of detail, although the Olympus enjoys the edge in the extreme corners, even when its aperture is opened a stop wider. The Panasonic improves when closed one stop to f5.6, but at this point it’s only roughly matching the Olympus when it’s two stops faster. Don’t get me wrong, the Lumix G 7-14mm is still delivering very impressive performance, it’s just that the Olympus is better.
Next let’s see how they compare mid-way through their focal length at 10mm, starting again with the Olympus 7-14mm f2.8 at 10mm f2.8, f4 and f5.6, and as before the cropped areas are indicated by the red rectangles on the full image below.
With the Olympus 7-14mm f2.8 zoomed to its mid-way focal length of 10mm, there’s fractional softness in the extreme corners when the aperture is wide open at f2.8, but the details sharpen up nicely from f4 onwards. I should also say it’s hardly bad at f2.8, I’m being very critical. Now let’s see how the Lumix G 7-14mm f4 compares.
Judging from the original images and the crops above I’d say the Lumix G 7-14mm performs very similarly to the Olympus 7-14mm f2.8 when both are at 10mm and sharing the same aperture values. I’d say there’s nothing significant between them in sharpness at 10mm f4 and f5.6. So the only advantage the Olympus has at 10mm is being able to open a stop brighter at the cost of only a fractional drop in sharpness in the extreme corners.
And now finally let’s see how they compare at their longest focal length of 14mm, starting again with the Olympus 7-14mm f2.8 at 14mm f2.8, f4 and f5.6, and as before the cropped areas are indicated by the red rectangles on the full image opposite.
At 14mm, the Olympus 7-14mm f2.8 performs very well, delivering sharp and crisp details across the frame, with only a tiny amount of softening in the extreme corners at f2.8. I’d say the slight drop in sharpness is even less than seen at 10mm, so represents very little to worry about. Now let’s compare it to the Lumix G 7-14mm f4 at 14mm f4 and f5.6.
In the crops above the Lumix G 7-14mm f4 looks fairly sharp across the frame, losing only a little sharpness at f4 in the extreme corners, along with exhibiting some vignetting. Once again it seems happiest closed to f5.6 where the corners sharpen and brighten to match the rest of the frame. Compared to the Olympus, I’d say the Lumix is a tad softer in the corners at 14mm at the same aperture values, so again the Olympus enjoys the lead and the benefit of also offering a brighter f2.8 option which matches the Lumix at f4.
So overall, a superb performance from the Olympus 7-14mm 2.8, that delivers very usable results across the focal range and at all apertures. If pushed, I’d say it’s strongest at 7mm, followed by 14mm, then 10mm, but really these are extremely minor differences that are unnoticeable in most situations.
Impressively the Olympus manages to match or slightly out-perform the already excellent Lumix G 7-14mm at the same focal length and aperture values. The Lumix can get very close on overall sharpness, but in some cases needs to be closed to f5.6 to do so. Meanwhile the Olympus will perform as well at f4 or in some cases f2.8, giving it a benefit of between one and two stops.