Canon just announced that it will launch its RF 85mm f/1.2 DS lens, where the “DS” stands for “Defocus Smoothing.” What does that mean exactly, and on a piece of gear that carries a hefty price tag, why doesn’t the fancy marketing mention that the lens lets in less light as a result of this funky new coating?
Canon’s new 85mm f/1.2 will sit alongside the existing RF 85mm f/1.2L USM that was released in June, a lens that’s notably $300 cheaper and already had a few people choking at the cost. Given that the EF version of this lens is an already expensive $1849, what has caused Canon to decide that an even pricier version is what customers are begging for?
This Defocus Smoothing which Canon has added at extra cost is an element in the lens given a coating that causes apodization. This is not too dissimilar to having a graduated radial filter — albeit as part of the series of elements that make up the lens — and thus making the transmission of light through the element non-uniform. As a result, out of focus areas tend to be smoother, with a more subtle transition, as can be seen in Canon’s example that features the bokeh balls in this video at 0:51. This occurs without compromising the sharpness of the in-focus areas, and as has been proven, Canon’s RF 85mm f/1.2 is an impressively sharp lens when shooting wide open.
BHPhoto produced an excellent video earlier this year (see below) that explains how this works and why you might want to have it in your arsenal. As David Flores notes, the effect with bokeh balls might be fun if somewhat tired (Instagram + fairy lights = cliche), but the effects that an apodization (APD) lens can create become more interesting when used to isolate a subject, particularly when integrating some foreground elements that are out of focus.
Canon’s press release contains a ton of example images to demonstrate the effect of its new lens and it’s very much a case of personal (and perhaps incredibly expensive) taste. Used poorly, it can look like a subject has been composited into a Gaussian blurred scene, but however much you might sneer at photographers who wax lyrically about the creaminess (not to mention butteriness) of their bokeh, the results can be pleasing. That said, if the most impressive part of your photography is how creamy the bokeh is, you’re probably doing something wrong.
Three grand is a lot to drop on a prime lens and if I were spending that much, I’d want that lens to be as versatile as possible. This is where APD lenses run into problems: this addition reduces the amount of light reaching the sensor, meaning that you’re going to be shooting at higher ISO levels than if you were shooting the exact same scene using the 85mm’s less expensive counterpart. Some APD lenses, such as the Sony FE 100mm f/2.8 STF GM OSS, have stabilization to accommodate slower shutter speeds when shooting handheld, helping to keep your ISO as low as possible.
For whatever reason, Canon has opted not to include stabilization it in its 85mm DS lens, so if you’re dreaming of packing one 85mm prime that’s perfect for weddings, this might not be it. As Fstoppers’ own Alex Cooke mentioned in this article, the 85mm DS at f/1.2 will be akin to using the 85mm non-DS at f/2.2 in terms of its capacity for gathering light. It seems that dreamy bokeh comes at a cost — both in terms of your wallet, and in terms of how much light it can deliver to your sensor.
You have to assume that if Canon has developed this lens, there must be a demand for it. If you have some thoughts on who might be splashing out, or if you plan on adding it to your stash of primes, let me know in the comments below.