Using the 'ol brick wall technique, in this post (Part 3) I am comparing the sharpness of the Sony E 16-70 on a NEX6 and the Olympus 14-54ii on the E-M5. Due to the crop factor differences (1.5x for Sony and 2x of Olympus) the effective field of view of these two lenses is actually very similar: 24-105 for the Sony and 28-108 for the Olympus.
I shot a brick wall at five different focal lengths using F4, F5.6, F8, F11, and F16 at each focal length. That's five f-stops and five focal lengths. That's a total of 25 tests with each lens, and a overall total of 50 images. All of these can be viewed larger and downloaded in full size here.
I used a single center focus point and aimed at the same spot in all images. They were all hand held, but all shutter speeds were "safe" speeds of at least 1/ focal length. Image stabilization was "on".
Below is what the brick wall scene looked like at five focal lengths. The ones shown here are the Olympus version, as is obvious by the 4:3 aspect ratio. The Sony images are a bit wider and less tall due to the 3:2 aspect ratio. Remember, the field of view is defined by the diagonal dimension.
All images were shot in RAW and processed at default Adobe settings in Lightroom 5. I viewed all the images in Lightroom using the X:Y comparison tool, and at 200% (2:1) on my 24" HD monitor. I compared center sharpness and then corner sharpness.
What I found:
Both lenses were similar in the center, and I believe sharp enough for any situation. In 23 tests I found the two lens to be identical. In two tests, I thought the Sony was slightly better. But remember, this is while examining at 200% and even then the center sharpness difference in those two instances was barely noticeable.
The Olympus is clearly sharper. In 21 tests the Olympus was sharper, having at least three corners sharper than the Sony corners. In one test the Sony corners were sharper. In three tests the two lenses were equal.
Here's a sample comparison with both combinations taken at 50mm-equiv, F5.6, aperture priority, base ISO.
Below are 1:1 crops from the center. Both lenses are sharp in the center.
|Olympus. 100% center crop. Very sharp.|
|Sony. 100% center crop. Very sharp.|
Below are 1:1 crops from the upper right corner. (1:1 crops are a lot kinder to the Sony than the 2:1 crops I viewed on my monitor.) Though both cameras are 16mp cameras, the compositions are a bit different due to the different aspect ratios. At 4:3, the Olympus gets a bit taller image; at 3:2 the Sony gets a bit wider image.
The Olympus is quite obviously sharper.
|Olympus. 100% crop from upper right corner. Sharp.|
(But more distortion than Sony... easily fixed in Lightroom)
|Sony. 100% crop from upper right. Not sharp.|
I was testing for sharpness. The Olympus was superior. On the other hand, the Olympus has some old technology in it. It focuses slowly on micro 43 bodies and is noisy. It also suffers from more chromatic aberration and distortion than does the Sony. The 14-54ii weighs nearly 16 ounces (17.5 ounces with the necessary adapter), while the Sony is smaller and weighs under 11 ounces.
It is also important not to forget about the 24mm-equiv. wide angle of the Sony. My own experience in the field is that with a lens like this one, 25%-33% of my shots would be at 24mm-equiv.
Perhaps the biggest consideration is price. The Sony costs $1,000 while the Olympus 14-54ii can be bought on eBay for under $300.
The Sony is a "good enough" lens. Even though it is softer in the corners than the Olympus, the corners are nevertheless sharper than what I am getting on the Sony 16-50 kit lens and on my Panasonic LX5, both of which are sufficiently sharp for 95% of my needs. I also think that you are getting a lot of lens from its 11 ounce body. Its ergonomics on the NEX 6 body is wonderful in my opinion. And again, don't forget about that 24mm wide angle.
However, for myself, I am seriously considering returning the lens. Yes, it is "good enough". I love the feel of the NEX body and this is my only option for a mid-range zoom with beyond-kit quality. The question for me is if it is worth $1,000... in light of what I already own in Olympus gear.