Reviewed: Canon EF 50mm f1.8 STM Lens

I got my hands on the recently released Canon EF 50mm f1.8 STM Lens. The 50mm f1.8 STM is a low-priced standard prime lens for the EOS range of Canon’s cameras with changeable lenses (DSLR and mirrorless like the Eos M series). The new lens got announced in May of this year only. The new 50mm f1.8 STM is the replacement for the EF 50mm f1.8 II which till date is Canon’s most successful lens ever. Is it required to say that the 50mm f1.8 II is actually 24 years old ? I guess we can agree that a change is overdue considering how technology on cameras has changed in the last 20 years.

The previous version, the EF 50mm f1.8 II , or the Thrifty Fifty, had been this successful for quite a number of reasons. It has a high flexibility, that means that if you git a full-frame camera it delivers standard coverage, but if you mount it on a APS-C like the Eos 760 for example it transforms into an 80mm equivalent that makes it perfect for portraits. The shots I did here have been done on the 760. Another good reason is the depth of field. With an f1.8 focal ratio it is very easy to blur the backgrounds, not matter if you are shooting people, details or products. The last and probably best reason is the unbeatable price coming in at just 125$ , which makes it as well the cheapest prime lens in the EF catalogue till date!


There are not too many differences between the old and the new one. Biggest one for me was the box. The new one comes despite having pretty much the same size on the lens itself in a way bigger box as you can see above. The new EF 50mm f1.8 STM keeps otherwise the same focal length, aperture and six element in five group construction. Different is that now you got seven instead of five diaphragm blades. This promises a bit smoother out-of-focus action and a closer focusing distance than before. So you can shoot now with a distance of 35cm instead of the 45cm the old lens delivers.

Biggest downturn for me on the old lens was the plastic lens mount, this finally has been replaced with a metal one. Of course this makes the new one slightly heavier by around 30 grams, which you don’t really feel. The filter thread changed as well down to 49mm, so your old filters or caps won’t work. The biggest change however is that the old micro motor AF system has been replaced with a smoother STM focusing system. albeit the gear-type which isn’t as quiet as the lead type used on the STM zooms. It is certainly more quiet but as well not as silent as Canon’s USM AF. But that is not a problem in any case. What is new for me , but typical for all STM-driven lenses, is that manual focusing works here “by-wire”. That means you are not really turning the focus ring, you are just turning a ring that triggers the AF motor. It works very well though.


The new “Thrifty Fifty” is a great prime lens and special for people who start experimenting with their equipment a great addition at this price.

Here some sample images:

IMG_0450 IMG_0452 IMG_0455 IMG_0459 IMG_0467 IMG_0468 IMG_0476 IMG_0479 IMG_0483

Canon EF 50mm f1.8 STM Lens


Optical Quality:


Mechanical Quality:





  • Much improved corner sharpness. Usable, even wide open.
  • Faster and more accurate auto focus.
  • 7 aperture blades and new aperture blade design lead to nearly rounded bokeh lights, even at narrower apertures.
  • Auto focus more silent.
  • Metal mount.


  • Center sharpness and contrast not as good as the old EF 50mm II.
  • Lens hood sold separately and overpriced.
  • Although the STM auto focus motor is more silent, it’s not as silent as you would expect it to be.
The following two tabs change content below.
Founder and Editor in Chief of the Acme Blog. Loves Photograhy, Gadgets, Movies and Restaurants aside from Cars.