Sunday, November 16, 2014

Canon EF 100mm f/2.8L Macro IS USM Review

The Canon EF 100mm f/2.8L Macro IS USM  is the professional-level upgrade to the EF 100mm f/2.8 USM macro. The build quality is better and it includes image stabilization. (... and being a red ring lens, it actually includes a lens hood, wonder of wonders....) Ostensibly, Canon does not put much thought into the aesthetics of their middle-tier lenses, but the 100mmL looks the part for being a professional-quality lens.

The IS system is rated at 1 extra stop of hand-holding advantage at 1:1 magnification, and 4 stops in normal usage. In actual practice, you can conservatively expect 2-3 stops advantage in real world usage, and as for macro work, the benefits seems to be "some." In other words, you can rely on the image stabilizer for ad hoc and emergency work in a properly lit circumstance, but its not a replacement for a proper tripod setup.

Minium focus distance (1:1 magnification) occurs at 0.3m. This is fairly standard for macro photography, and provides adequate working space to illuminate the subject. The front thread diameter is 67mm. If you are using this lens primarily in a controlled studio environment, it makes little sense to use a protective filter on it unless you are extremely concerned about safety.

Image Quality

In truth, almost all prime lenses between 85mm and 200mm are sharp and produce crisp images. The differences between  lenses tends to be in usability... flare resistance, ghosting, etc. The 100mmL is no exception: it's a generally good optic with few relevant flaws. There are some downsides, but for the most part they don't matter for the intended purpose of this lens. If you are new to dedicated macro lenses, they aren't just about close up work. The 100mm focal length and reasonably fast f/2.8 aperture also allow for decent portrait work.

Because lens optical performance is a complex topic, the objective description of such is beyond the scope of this blog. Though there are many aspects to quantify (resolving power, field curvature, distortion, aberrations, etc.), a general sense of a lens’ character can be determined without resorting to lab testing. The following is one aspect; bokeh and apparent background blur with the subject at short distances. This first set is similar to how you would use this lens for a portrait work.

As you would expect for for a dedicated optic at this focal length, geometric distortion is virtually non-existence. There is a palpable amount of vignetting at f/2.8 that clears up by f/4. It's not excessive, but it's more in line with what you would expect a f/1.4 short prime to do rather than a longer f/2.8 lens.

Lateral chromatic aberration is very well controlled throughout the aperture range. It's hardly noticable except when using extreme file crops. The bokeh is extremely good, and one of the more understated benefits of this lens. Note how uniform and smooth the out of focus highlights are at the wider aperture. Though the above samples do not demonstrate it, the 100mmL is somewhat prone to longitudinal chromatic aberration, which can manifest as faint green halos in out of focus areas behind the point of focus. As with all macro lenses, the 100mmL at closest focus distance, the depth of field is razor thin:

There's very little to complain about for close up work. This lens is the standard-bearer for Canon's macro-photography line-up, and it does the job very well. As mentioned above, there are limits to what you can achieve with hand-held work; 1:1 images require an extremely steady head, even with IS turned on. (Click to see at full image size.)

Canon EOS 6D. Full size, f/4

100% crop

Concluding Thoughts

For macro work, this the 100mmL is a great lens. It's not cheap, but it's not expensive for an "L" lens either. However, there is one caveat to remember about this lens: all of the virtues that it posses are present in the less expensive Canon EF 100mm f/2.8 USM, save for image stabilization. If you are constantly doing close up work in a controlled studio setting, the non-L lens makes much more sense, as you will be shooting on a tripod in any case. However, the extra price of the L lens doesn't represent added quality so much as it means added versatility. Macro lenses are uni-taskers, and if you subscribe to the Alton Brown school of thought, single-use tools are inferior to multi-taskers if it means that you rarely use that tool because of its single-mindedness. The inclusion of IS on the 100mmL won't make it a portrait-lens replacement for a 85mm f/1.2L, but it does add an extra dimension to its capabilities.

With thanks to Broadway Camera

No comments:

Post a Comment