Conclusion
Pros
- Decent resolution wide open and excellent sharpness stopped down
- Very pleasing bokeh
- Lightweight and compact
- Well constructed for the price
- Excellent color and contrast
- Good control of lateral chromatic aberration
- Low distortion
- Reasonably priced
Cons
- Autofocus is slow, noisy and can struggle to lock focus in low light or stopped down Edit: with firmware v03, Autofocus is reasonably quick and very accurate in a variety of shooting conditions, but can still struggle in backlit situations.
- Some softness at f/1.8, especially close up
- Longitudinal CA can be an issue in some cases
- Average flare performance
The FE 50mm f/1.8 is a tough one to judge. Optically, it’s really a very good lens. It’s very sharp over almost the entire aperture range, it has beautiful color and contrast and very pleasing bokeh. It’s also got low distortion and while the flare performance isn’t great, it’s not the worst I’ve seen. While the cons list above is short, the first one is the only major issue with the lens, but it’s quite significant. To be blunt, the autofocus on this lens sucks. It’s slow, it can struggle to lock in low light, it has some trouble stopped down even in good light Thankfully, Sony has remedied most of the earlier autofocus woes with the latest firmware. While there are faster focusing lenses out there for sure, the FE 50mm f/1.8 on firmware 3 is plenty capable for everyday shooting. The DC motor used for focusing is a bit noisy.
When comparing to the venerable 55mm f/1.8, you get slightly less background blur and a bit softer images wide open. Otherwise, the two lenses actually compare very favorably when looking at the optics.
But ultimately, when you consider whether you should buy the FE 50mm f/1.8, the question you have to ask is: how important is quick autofocus to my shooting? If you can wait for it to lock, or will be using the lens for tripod work and can manually focus, it’s quite an outstanding lens. If you are planning on using the lens for event shooting or other situations where fast and accurate autofocus is critical, you’ll want to give this lens a pass and move to the FE 55mm f/1.8.
With the autofocus on the FE 50mm f/1.8 now predominantly fixed via firmware update, the choice between these two lenses becomes much more difficult. The 55mm f/1.8 does still focus a little faster, and much more quietly. It’s also a little sharper at wide apertures, and more even throughout the frame stopped down. However, given the wide gulf in cost, I think the average shooter will probably be better served by the 50mm f/1.8. If you are a big 50/55mm fan, and will use the lens for a large portion of your work, or require a quieter focus motor (think weddings), the 55mm f/1.8 will be the one you’ll want. However, for daily shooting, I think most photographers will be better served by going with the 50mm and putting the extra $750 towards another lens or two.
Sample Images
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Your review is spot on with mine. I got mine the 1st day they were delivered and returned it after 2 week. Perhaps if Sony does a firmware update to allow Phase Detection in the A7II and older I would reconsider, but as it they should have spent an extra $50 to provide a better AF. I was so irritated to have to return it.
Agree with your frustration, it sucks to be hampered by such an obvious drawback, and I wish this was a first for Sony. However, I think it is a bit more complicated than a $50 upgraded part. The 50 1.8 is the only FE lens (to my knowledge) that does use an SLR design (double guass—like most nifty fifties) and moves the entire optical component instead of using internal focus. Moving that much mass in a CDAF system is difficult. Fuji’s original 35mm f1.4 struggled as well for the same reason I believe. Certainly a better motor would help but even the top shelf GM 85mm (which is internal focus but uses much heavier elements) is relatively slow.
I hope you’re right and improvements in Sony’s PDAF system will yield acceptable results in the new low- mid-range A7 models. For now I’m sticking with the FE 55mm. I waiting patiently and snagged my copy (very good) for ~$500. Still much more than the 50 but closer…
You can’t paint all double Gauss lenses as a SLR designs, especially when it comes to 50mm. There are quite a few 50mm dougle Gauss rangefinder lenses, plenty of RF double Gauss lenses at 35mm and 90mm as well. Obviously a lot of double Gauss SLR lenses as well, but that doesn’t make it an “SLR design.” A double Gauss makes a lot of sense for RF flange distances between 35-90mm. I think there were even double Gauss 28mm lenses (Canon LTM IIRC), something you could never pull off on an SLR.
Quick update – after latest firmware update on 09/09 autofocus is much better (although not perfect). Tested on a6k, continuous focus works quite good, singiel is improved and works “ok”.