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Comparison with Sony Planar T* FE 50mm F1.4 ZA -) Both wide-open, the 55/1.8 out-of-focus rendition is smoother even when compared to the 50/1.4 ZA when the background is close to the subject. Whenever the background is further away, the advantage goes to the faster lens.
-) The 50/1.4 is much better corrected for CA and LoCA.
-) The 50/1.4 ZA and FE 50/1.8 ZA are very comparable wide-open in terms of sharpness but the 50/1.4 has higher micro-contrast.
-) The 50/1.4 at f/1.7 is noticeably sharper than at f/1.4.
Admiring Light While the price is a little high, it’s not outrageous considering the quality of the optics. The lens is very sharp, even in the corners at f/1.8 with great bokeh, excellent contrast and color and few lens aberrations. It also is relatively compact and has quick, quiet and accurate autofocus. [...]. If you want a normal lens for your A7 series camera, you really can’t go wrong with the lens. However it’s much harder to recommend for APSC only shooters.
the Sony FE 55mm F1.8 ZA is quite simply one of the sharpest lenses we've seen. It's clearly been designed with the demands of modern high resolution sensors in mind, and is easily a match for the currently class-leading resolution of the Alpha 7R. It's impossible to ignore its price, but in this case, there's a pretty good argument that you get what you pay for.
The image center is sharp at f/1.8 but the outer image region isn't quite as impressive here; sharpness across the image with f/4. The lens produces some heavy vignetting at maximum aperture. Lateral CAs are no issue at all nor are image distortions. The critical blur in the image background is nicely rendered whereas the foreground isn't as pleasing. A fair share of bokeh fringing is also present.
On the mechanical side we have nothing but praises. High price tag.
It's perfectly usable wide open though you may be affected by vignetting and purple fringing. Between F2.8 and F4, the lens becomes exceptional. Flare control isn’t the best but it’s also not the worst I have ever seen. The lens size pairs very well Sony mirrorless bodies. Even with harsh back lighting, the Sony Zeiss 55mm/F1.8 produces very nice contrast.
But the Sony Zeiss 55mm/F1.8 is priced nearly $1000 that is more expensive than most 50mm F1.4 lenses
Pros: compact and solidly sealed casing of high quality, very good image quality in the frame centre already from the max aperture, sensible image quality on the edge of the APS-C sensor, imperceptible lateral chromatic aberration, moderate distortion, lack of serious problems of spherical aberration, slight astigmatism, blurry areas pleasing to the eye, accurate/fast/silent autofocus.
Cons: longitudinal chromatic aberration, vignetting, high coma, price.
Pros: fantastic size and weight, great build, including moisture and dust resistance, fast/accurate autofocus, autofocus is completely silent in both video and stills shooting, excellent sharpness across the frame on APS-C and Full Frame, low levels of distortion and acceptable levels of vignette, eye AF works well.
Cons: bokeh rendering is a little busy, high price tag for an f/1.8 lens.
It’s one of the sharpest normal lenses around [...] At the same time you get smoother bokeh than with most other normal lenses. Cat-eyes and onion rings can be a bit distracting at times though. Flare which is very well controlled. Handling of the smallish lens is pleasant with quick AF and a very good balance. I found the manual focusing experience unpleasant. The only aberration which can be really bothersome is LoCA. I should also mention the strong vignetting.