The Canon 50mm ƒ/1.8 II – considered the “best value” lens by many reviewers all over the internet. It is probably the most-owned lens amongst Canon’s offerings because it’s well… cheap. Real cheap. I picked this little guy up to replace the one I had. Back in college a friend picked my camera bag up off of the backseat of my car with the back unzipped and a lot of my stuff fell out. Fortunately my 70-200 ƒ/4.0L rolled out onto the backseat and my flash did the same. However, my 50mm ƒ/1.8 II fell to the street and plop – the front element popped out of the body of the lens. I put it back together later in my room and it seemed ok, but I realized the next time I went out with it that the autofocus would jam after a little turning. That, and the element would pop out if you rotated the lens. Oh boy.
So, years later I have another one. I already have the 50mm ƒ/1.4 USM so many people are probably wondering why I’ve got the ƒ/1.8 II as well after picking up the ƒ/1.4! It’s simple really – I had a gift card for Amazon (only like $10) and the lens is $100 free shipping with my Prime account. So, I picked it up as an alternative to higher dollar lenses should I want to go out some place where I might want to bring less expensive-looking optics. That, and it’s kind of a reminiscent piece given mine broke (not due to my own doing and all) a long while back. Another convenience about having it is that my 35mm film body (Canon Elan 7NE) had the 50mm ƒ/1.4 USM on it when I set i t up in my Pelican Case. But, without the lens on, the camera fits loosely in the compartment and flops around. So, I can leave the ƒ/1.8 on and all is secure.
I had to write up some instructions for a photography station at work and as part of that process I had to provide pictures of the setup. I used the 50mm ƒ/1.8 II to provide wider angle shots of the station which was fun because it reminded me of my first DSLR and my former 50mm ƒ/1.8 II and how simple my setup was back then. I set the lens to ƒ/1.8 and fired off a shot showing the station in focus but the background out of focus:
This lens is so easy to make things “look good” with the wide aperture and relatively sharp output (for what it is!). When you view images from this lens its hard to believe that the lens costs so little. I have never used the 50mm ƒ/1.8 original version but I understand that it performs about the same as the II but has better construction. Compared to the 50mm ƒ/1.4 USM, the ƒ/1.8 is cheaply made, light, small, and relatively “toyish” – heck, the lens mount itself is plastic! If that doesn’t convey cheap, then you won’t find a single issue with this lens. The 50mm ƒ/1.8 I, which performs almost identically to the ƒ/1.8 II but the first version is metal with a metal lens mount. Of course the 50mm ƒ/1.4 USM offers great build quality including a metal lens mount and beefier focusing ring. The ƒ/1.8 II doesn’t really feel like a real lens, comparatively. But, if you put all of that aside then the thing performs amazingly:
So, like almost all review sites, I figured I’d show what the biggest difference is between the ƒ/1.8 vs ƒ/1.4 aside from a slightly larger aperture. The biggest optical flaw of the ƒ/1.8 is that it produces some of the harshest bokeh of all. The 50mm ƒ/1.8 II has curved aperture blades however it only has 5 of them. So, when taking a picture with a subject in the foreground, the highlights behind the scene will exhibit very hard, 5-sided polygonal bokeh balls. This is not an issue with the lens wide-open at ƒ/1.8 because the aperture blades are cleanly tucked away, but as you stop the lens down to gain more sharpness (given this lens isn’t that sharp at ƒ/1.8) and depth of field, you will notice the harsh bokeh. Here are the 50mm ƒ/1.8 II aperture blades at ƒ/8.0:
The 50mm ƒ/1.4 USM also has curved aperture blades but has 3 more for a total of 8 blades. The result is that any highlight bokeh balls in the background of an image produced with the 50mm ƒ/1.4 USM will demonstrate a much smoother bokeh. The smoothness of bokeh can be attributed to both the ƒ/1.4 maximum aperture as well as the additional blades. In geometry class you learned that if you drew tangential lines around the circumference of a circle, you could in theory draw a perfect circle (with infinite lines). But, since we cannot have infinite aperture blades, we deal with what we’re given – the 8 blades do not form a perfect circle stopped down to ƒ/8.0 as can be seen above, but at slightly wider apertures (ƒ/1.8 – 4.0 for instance) the aperture still provides relatively round, smooth bokeh highlights:
If you desire the look of smooth, completely round bokeh highlights throughout all apertures and want a 50mm lens then your only option from Canon is the 50mm ƒ/1.2L USM. However, that lens is now retailing at around $1,550 USD – a huge leap above the ƒ/1.8 at $100, and the ƒ/1.4 at $379. Of course, the 50mm ƒ/1.2L performs great, even if it isn’t very sharp, but we all know that and expect that from a professional L-series lens with a huge price tag. The 50mm ƒ/1.4 and 50mm ƒ/1.8 trump it in value, weight, and being inconspicuous. That said, I want to follow this brief review/article up with some example photos at various apertures to show bokeh highlights.
The photo set below are from the 50mm ƒ/1.8 and 50mm ƒ/1.4. I will shoot each lens as wide as they go, then offer the following image from the opposite lens. Since the 50mm ƒ/1.8 cannot shoot at ƒ/1.4, I will start with the 50mm ƒ/1.4 at it’s widest aperture:
It is fairly easy to see the differences here even if you aren’t a photography expert. As the aperture number (f-number) goes up, the aperture opening size goes down, the blades close, the roundness is lost, and the background detail becomes more in focus and as a result more harsh in appearance. I feel that people would agree unanimously that shooting these lenses with an aperture of ƒ/8 or smaller will result in a rather distracting background highlights. But, I suppose that one would expect that to happen with almost any lens. Wide angle lenses, though, tend to simple render the background as a sharp, detailed scene compared to longer normal and telephoto lenses which render them still out of focus but busy.
This isn’t mean to encourage or discourage the purchase of one lens over the other but rather to show the potential in a $100 lens (even if it is cheap-feeling and completely plastic), while also showing that the mid-range 50mm lens offers better build quality but also better optical quality especially in the bokeh department. Other things like sharpness at varying apertures, flare control, vignetting, contrast, etc., are all improved when using the 50mm ƒ/1.4 USM over the ƒ/1.8 II, but all in all, the ƒ/1.8 II is a very good performing lens especially given how little it costs.