A HUGE step-up from the original EF 50mm 1.8 lens
BACKGROUND:Let me start by saying I'm a hobbyist photographer and I've been shooting with a Canon Rebel T1i (500D) for the past 10 years. I was heavily budget-constrained, so I rocked my OG Canon 50mm 1.8 (non-STM) version since 2010. For $150 at the time, it was a fast lens that was affordable to most novice DSLR photographers like myself.After recently getting back into my hobby after a couple years of being tied up with other stuff, I noticed my 50mm was producing softer images than I remember. It had never been dropped or otherwise abused, but it just seemed to be not performing the way I expected. The autofocus was reasonably quick, but very loud and lacking in smoothness and accuracy.BUILD QUALITY:Now that I had a little more money saved up, I decided to purchase the updated STM version of this lens and this is a MASSIVE leap from the old version. The build quality and finish, while still being mostly plastic, feels way more robust. The cheap shiny finish of the old version was gone in favor of a beefier, textured plastic. Also, the lens mount itself is now made of aluminum which fits very firmly against the camera body.PERFORMANCE:After testing it out I can say BOY is this thing tack sharp. With my old lens, I had to shoot at F/2.8 if I wanted anything with usable sharpness. This lens is producing razor sharp images wide-open and the autofocus is extremely quiet, smooth and accurate. It is still audible but you really have to listen for it. As far as speed goes, it doesn't seem much quicker than the old 50mm, but is way more accurate and reliable. The quiet STM focusing makes this usable for video, whereas the old version simply wasn'tJust keep in mind the manual focus still uses an internal motor to move the lens elements. With the camera turned off, turning the focus ring doesn't do anything. Also, on an older camera body like my T1i, turning off the camera wouldn't retract the lens barrel. Now that I've upgraded to a Canon 90D, I noticed turning off the camera will auto-retract the lens barrel all the way, making it suitable to store in a bag without damaging the lens.SUMMARY:If you're getting into DSLR photography and have a reasonably modern Canon DSLR body, this lens is a must-have. For $125 at the time of this review, it's even cheaper than the old lens (especially accounting for inflation), while out-performing it in nearly every metric. Prime lenses are the kings of affordable speed and sharpness, and this lens is right up there with the very best primes you can buy for under $500. If you aren't jumping on the mirrorless camera bandwagon, this is an excellent lens for both full-frame and crop sensor Canon DSLRs.