Sony E 50mm f/1.8 OSS SEL50F18
Lab Test Results
June 22, 2012
by Andrew Alexander
The Sony E 50mm ƒ/1.8 OSS was released at the end of 2011, to accompany the Sony NEX-5 and future NEX E-mount designs. The lens is larger than one would think a typical 50mm prime to be, but then, this lens incorporates Sony's image stabilization system (OSS - "Optical SteadyShot").
Designed to fit the APS-C sensor in the NEX camera, the lens will produce an effective field of view of around 75mm. E-mount lenses are not compatible on other Sony cameras. The lens takes 49mm filters and is available now for around $300.
The Sony E 50mm ƒ/1.8 produces sharp images, perhaps not straight out of the gate at ƒ/1.8 where we note some light softness across the frame. This improves as the lens is stopped down, getting obviously better at ƒ/2.8, but stopped down to ƒ/4, images are almost tack-sharp from corner to corner. For absolute maximal sharpness you'll need to stop down to ƒ/8, but for practical usage you won't see much of a difference between ƒ/4-ƒ/8, if not at ƒ/2.8.
Diffraction limiting sets in at ƒ/11, but the impact at that aperture is so slight as to be unnoticeable. At ƒ/16 there is a light softness across the frame, and fully stopped-down at ƒ/22, it's slightly softer.
The Sony E 50mm ƒ/1.8 provided us with some of the most complex results for chromatic aberration testing we have had to date, so strap yourselves in, there's a bit of discussion here.
Starting with the results from our DxO testing software, you would think that the lens is actually really amazing for resisting chromatic aberration, especially at its widest apertures. And this is indeed true - in the case of conventional, lateral chromatic aberration, which typically manifests as multi-colored fringing in areas of high contrast.
But take a look at the upper left corner of our ƒ/1.8 sample image, and we see quite a different story:
That's a lot of red fringing. What we are seeing here is longitudinal chromatic aberration, which we have seen from time to time in fast prime lenses. (See the excellent article by Paul van Walree on chromatic aberration for a discussion of the two primary types, how they occur, and examples of each.)
In this case, the red channel's point of sharpest focus is pretty dramatically out of step with that of the green and blue channels. The effect is most dramatic at maximum aperture, decreasing rapidly as you stop down. By ƒ/5.6 or ƒ/8, it's pretty minimal. But at ƒ/1.8, wow - look out. CA can be broad or compact, bright or subdued; this lens' CA tends towards the compact/bright side of things. When the lens is at its sharpest focus, high-contrast objects will have fairly bright red outlines around them, even in the center of the frame. At the periphery of the frame, things get even a little stranger, as there's considerable astigmatism in the red channel, particularly along the edges and corners of the frame. This causes red blobs to poke out the sides of objects in directions perpendicular to a radial axis passing through the center of the frame. The lens' CA behavior will be an issue if you're shooting anything with sharply contrasting, black-against-white elements in it (like test charts), but less so if your subjects have more gradual tonal changes.
Usually, longitudinal CA is a minor issue, but the Sony 50 ƒ/1.8E shows that it's still a factor in modern lens design.
Corner shading is really only a light issue when the lens is used at its widest apertures (ƒ/1.8 or ƒ/2) - in this case, we see extreme corners that are around 1/3 EV darker than the center of the frame. At any other aperture, light falloff is negligible.
There is very little distortion with this lens: according to the numbers there is some very light pincushion distortion in the corners, but that's about it.
The lens takes under a second to focus from close to infinity, and does so silently. Full-time manual focusing is possible, with a helpful 7x and 14x magnification be available to assist. Attached 49mm filters will not rotate during focus operations.
With a magnification of 0.16x, this is not a lens you want to go to for macro work. The lens' minimum close-focusing distance is 39cm, or just over a foot.
Build Quality and Handling
The Sony E 50mm ƒ/1.8 OSS is small and light, around 7 ounces, simple in its design. It is encased in a silvery-metal shell (also available in black beginning in September 2013), uses a metal lens mount to attach to the camera body, and offers plastic threads for attaching 49mm filters.
There are no control features on the lens other than the focusing ring: all applicable functions are controlled in the camera body. The ring itself is around 1'' wide, composed of fine metal ribs, and will turn forever in either direction.
An optional black, round lens hood (model ALC-SH116) is available for this lens, which adds 1 3/4'' to the overall length. The lens attaches via bayonet mount and can be reversed for storage on the lens.
The E 50mm ƒ/1.8 offers Optical SteadyShot stabilization, and while Sony claims it offers approximately 4 stops of shutter speed advantage, our testing suggests that number is more like 2 1/2 stops; see our IS Test tab above for a more detailed look.
Given the relatively new state of Sony's E-mount, it's unsurprising that there are few options in this category.
Sony 50mm ƒ/1.8 SAM ~$150
With the aid of the LA-EA1 mount adapter, one can use regular Sony alpha lenses on NEX bodies, and thus one could use this lens on the NEX body. The SAM version of the Sony 50mm ƒ/1.8 performs quite similarly to the E-mount version (although the E-mount version is noticeably better at ƒ/1.8 and ƒ/2), making us wonder if Sony didn't start with the SAM design and add on its OSS stabilization.
Sigma 50mm ƒ/1.4 EX DG HSM ~$450
It gets a bit convoluted, but Sigma produces this lens in the Sony mount, so again, with the LA-EA1 adapter this lens could be mounted on a NEX camera. That done, you don't seem to get appreciably better results than the Sony E 50mm.
The Sony E 50mm ƒ/1.8 OSS is a capable lens, marred only by some poor CA performance when used wide open; even then, depending on the subject matter, it may not be particularly noticeable.
The VFA target should give you a good idea of sharpness in the center and corners, as well as some idea of the extent of barrel or pincushion distortion and chromatic aberration, while the Still Life subject may help in judging contrast and color. We shoot both images using the default JPEG settings and manual white balance of our test bodies, so the images should be quite consistent from lens to lens.
As appropriate, we shoot these with both full-frame and sub-frame bodies, at a range of focal lengths, and at both maximum aperture and ƒ/8. For the ''VFA'' target (the viewfinder accuracy target from Imaging Resource), we also provide sample crops from the center and upper-left corner of each shot, so you can quickly get a sense of relative sharpness, without having to download and inspect the full-res images. To avoid space limitations with the layout of our review pages, indexes to the test shots launch in separate windows.
Sony E 50mm f/1.8 OSS SEL50F18
Sony E 50mm f/1.8 OSS SEL50F18 User Reviews
4 out of 10 points and not recommended by andred (1 reviews)very sharp, lightweightDifficult to autofocus when used for rapid, candid, interior photography
My overall rating of 4 is for those occasions when I'm using the lens for rapid, point-and-shoot *interior* photography with the Sony NEX 7 set to "autofocus", in poor to average shopping mall lighting conditions.reviewed December 3rd, 2015 (purchased for $350)
However for street photography under good light this lens is excellent and I would give it a rating of 10.
8 out of 10 points and recommended by louisjaffe (6 reviews)Sharp, optical image stabilization, affordablesample-to-sample variability
I compared the Sony 50mm f1.8 OSS to the Zeiss 55mm f1.8 on a Sony Alpha a6000 in various shooting situations. The Sony lens is 1/3 the price of the Zeiss, or less.reviewed July 31st, 2014 (purchased for $350)
Surprisingly the Sony (with rev 02 firmware) focused quicker in low light than the Zeiss, and could lock focus in some situations where the Zeiss only hunted. As observed by another writer in this thread, updated firmware for the Sony lens takes advantage of fast hybrid autofocus on the a6000 (NEX-7 doesn't have this feature). The Sony 50mm also grabbed more frames that were sharp at low shutter speeds, thanks to optical image stabilization, which the Zeiss doesn’t have.
This Sony 50mm is inferior to the optically superb Zeiss 55mm in contrast, color rendition, and flare resistance. But I had to look closely and repeatedly on a well-calibrated 27-inch monitor to see the difference.
Admittedly, I had to try three samples of the Sony lens to find one that performed to full potential. The first two were sharp at center, but fell off towards one side of the frame or the other at wider apertures.
Comparing these two lenses is apples-and-oranges, because the Zeiss 55mm covers full frame, the Sony 50 mm only APS-C. You could say I took the Zeiss slumming by comparing it to this much cheaper Sony lens. Still, I was surprised by how well my cherry-picked sample of the Sony 55mm f1.8 OSS performed.
10 out of 10 points and recommended by Beachrider (22 reviews)Light, fast, very sharp, OSS effective, key APSC focal length, contrasty, fast focus, useful hood,Not a pancake, no distance meter, not as fast focus as A-Mount w/LA-EA2
A very useful lens. All advanced tracking and field detection function while minimizing the limits of CDAF environment. Use with A6000 and upgraded firmware VASTLY improves focussing with Hybrid-AF on that camera.reviewed June 9th, 2013 (purchased for $300)
9 out of 10 points and recommended by brugj03 (14 reviews)Extremely sharp, well balanced on nex 7, very cheap for the performance,OSS and fast.Inconsistant production quality
Bought this lens as a short portrait and landscape lens.reviewed November 4th, 2012 (purchased for $300)
It`s very sharp indeed even ad full aperture, which is a fast 1.8.
There are some issues with mechanical noise, i brought 1 back to the store which had severe mechanical noise, my current also has some noise but not that bad.
The focus ring turns very smooth and feels right.
I`m very pleased with the image quality which is contrasty and clear, the OSS makes this already fast lens even better which is incredible.
I would recommend this lens for all nex shooters. It`s great.
8 out of 10 points and recommended by dugong5pm (52 reviews)fast, sharp, has OSS, light, nicely buildnone
I wish all lenses were this good. It has so much values in a fairly low price. It has good performance, light, nicely build, and it has OSS too! this OSS can be really handy in most situations, considering this is more like a short telephoto lens (75mm equivalent). I think nothing to be complained about this lens. I use this along with the 16/2.8 and Sigma 30/2.8 (as a normal lens), and they never let me down.reviewed October 20th, 2012 (purchased for $300)