In this third part of my « 50mm » series for the A7R, I will compare the Sony Planar 50/1.4 ZA (A-mount) to the Sony Sonnar 55/1.8 ZA (FE-mount).
If you haven’t done so, you’re welcome to read the first two parts:
The Sony 50/1.4 ZA is very nicely built, quite compact for an SLR lens but thick with 72mm filters. It’s roughly the same size as the Sont 85/1.4 ZA. Autofocus is fast and « snappy » like other ultrasonic SLR lenses. Manual focussing is quite responsive and precise, and feels much better than the fly-by-wire of the FE lenses.
Sony 50/1.4 ZA to the left, Sony 85/1.4 ZA to the right. Notice that the Zeiss logo got bigger on the 50/1.4.
The length is only slightly longer than the 55/1.8 but much thicker: 72mm filters vs 49mm.
But the 50/1.4 becomes noticeably longer with the LA-EA4 adapter. Although the LA-EA4 adapter is a bit large, it also gives a new home to all the A-mount lenses on the A7x cameras. That is, lenses behave like native lenses with fast AF, automatic aperture, and EXIF information.
Sharpness will be shown in the center, mid area, and corners. Shots are taken from a lovely old building in the Palais Royal, near the Louvre museum.
The 50/1.4 is already decent wide open but not really sharp.
At F1.7/1.8 the 55/1.8 is a bit sharper.
From F2.0 to F4.0, the center and corners are similar between the two lenses but the 55/1.8 is sharper mid-frame.
The 50/1.4 catches up at F5.6 & F8.0.
Both lenses are very good but the 55/1.8 is a bit better at large apertures.
In real life scenarios where using large apertures result in out-of-focus corners and F5.6 & F/8.0 are used for flat subjects, you probably won’t see the difference.
For both lenses, the bokeh is quite smooth, above average for « 50mm » lenses.
In the samples below (all at F2.0), the 50/1.4 is shown first.
beautifullenses 
Thanks for the comparison. I was always wondering how they looked side by side. To my eye, the 55 is noticeably better.
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Yes, the 55/1.8 is sharper but you might not see the difference in real life situations.
Also, the native AF of the A7r is not as reliable as the one of the LA-EA4 adapter, especially for low contrast scenes.
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55 is sharper, but the 50 has beter bokeh suprisingly
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Sharpness and bokeh are harder to mix on shorter focal lengths
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Were these test photos taken with autofocus or manually focussed?
I find it interesting that the 50ZA seems to be a little worse in the center and the mid areas but better in detail (yet more hazy) in the corners.
P.S.: You might want to check the links to the full size images, they’re mostly messed up.
J’aimeJ’aime
I used AF, but also double checked against some manually focussed pics.
Links are fixed now, thanks
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