Canon 80D Optics

Zoom
The Canon EF-S 18-135mm IS USM lens offers more zoom ratio than the typical kit lens, with fair optical performance for its class.

This lens has a versatile optical zoom ratio of 7.5x with a 35mm equivalent range of about 29-216mm, thanks to the Canon 80D's ~1.6x crop factor. That's much more "reach" than offered by a typical 3x kit lens.

The EF-S 18-135mm IS USM is fairly sharp across most of the frame at 18mm (~29mm eq.) and f/8, though it's not tack sharp, and there's some mild blurring and coma distortion visible in the extreme corners. Chromatic aberration is well-corrected by the 80D's processing, however keep in mind CA correction contributes to a loss in edge acuity. (See below for more on C.A. correction.) At 35mm (~56mm eq.) and f/8, sharpness across the frame is good, but some softness is still visible in extreme corners. Sharpness at 135mm (~216mm) and f/8 is not bad across much of the frame, but corners are still somewhat soft. (It's difficult to determine corner performance as well as sharpness at full telephoto in these shots as they are meant primarily to demonstrate zoom capability; see below for lab test results.)

Macro
A larger-than-average macro area with good detail. Flash throttled down well.

The Canon EOS 80D's macro performance will of course depend entirely on the lens in use. With the 18-135mm IS USM lens set to 135mm, the Canon 80D captured a somewhat larger-than-average minimum area measuring 2.95 x 1.97 inches (75 x 50 millimeters). Details are good but a touch soft in the center of the frame at f/8, and only a little softer in the corners. (Most lenses have some softening in the corners at macro distances, however the 18-135mm IS USM performed better here than most.) The Canon 80D's flash throttled down well producing a good exposure, and coverage was very even with no detectable shadow from the lens barrel.

Geometric Distortion
Higher than average barrel distortion at wide angle and moderate pincushion distortion at full telephoto.

The Canon EF-S 18-135mm IS USM lens produced images with about one percent barrel distortion at wide angle, which is higher than average and noticeable in some shots. At the telephoto end, there was about 0.5% pincushion distortion, which is also higher than average though not quite as noticeable. The Canon 80D does not correct for geometric distortion in its JPEGs by default as uncorrected RAW files exhibit identical amounts, however in-camera distortion correction is available (see below). Geometric Distortion is the tendency for the lens to bend straight lines outward (like a barrel -- usually at wide-angle) or inward (like a pincushion -- usually at telephoto).

Chromatic Aberration and Corner Sharpness
Low chromatic aberration in JPEGs with the 18-135mm IS USM lens because the 80D suppresses it by default, but high CA in uncorrected RAW files. Mild to moderate softening in the corners.

Chromatic Aberration. Chromatic aberration in the corners with the Canon 18-135mm IS USM lens is moderately low at wide angle and low at telephoto, but like most cameras these days, the Canon 80D suppresses lateral chromatic aberration by default in its JPEGs. See below for examples with chromatic aberration correction disabled.

Corner Softness. The 18-135mm IS USM lens produced soft corners when wide-open at maximum aperture. At full wide angle, corners on the top of our test target are just slightly softer than the bottom, but performance is pretty symmetrical. The center of the image has decent sharpness but is not tack sharp. Wide-open at full telephoto, the bottom left corner is the softest, and slightly softer than wide angle, but again performance is fairly symmetrical. The lens is fairly sharp in the center at full telephoto, though again not tack sharp, and just a bit softer than wide angle.

Vignetting. Vignetting or corner shading is mild in the above crops, but that's because the Canon 80D's Peripheral Illumination Correction is enabled by default. See below for comparisons with it off.

Performance at f/8: Corner performance improved when stopped down to f/8, a little more so at wide angle than telephoto, but corners are still not tack sharp. Performance in the center also improved stopped down to f/8, but only slightly.

The new Canon EF-S 18-135mm f/3.5-5.6 IS USM kit lens isn't tack sharp but overall optical performance is not bad for a 7.5x consumer lens priced at under US$600.

Lens Corrections
The Canon 80D offers built-in lens corrections from chromatic aberration, geometric distortion and corner shading which can be individually controlled.

Chromatic Aberration Correction

Chromatic Aberration Correction is enabled by default for supported lenses on the Canon 80D. As you can see, the 18-135mm IS USM lens generates moderately high to high levels of lateral CA (crops on the right), but the Canon 80D's Chromatic Aberration Correction was very effective at removing almost all the lateral chromatic aberration at wide angle, leaving very low amounts of blue fringing. However, high-contrast edges can look at little fuzzy as a result. It also did a good job at telephoto, but perhaps overcorrected a bit. (Note that corner shading and distortion correction were also enabled for the crops on the left.)

Geometric Distortion Correction

Distortion correction is the only lens aberration correction that is disabled by default on the Canon 80D. Above are results with it enabled. As you see, geometric distortion was reduced to very low levels at both wide angle and full telephoto with distortion correction enabled, but do be aware the resulting image is slightly cropped.

Peripheral Illumination Correction

The Canon 80D provides what the company calls "Lens Peripheral Illumination Correction," which corrects for lens shading (commonly called "vignetting"), attempting to produce a more uniform exposure across the frame by compensating for the light fall-off seen with some lenses in the corners of the frame. PIC is enabled by default.

Mouse over the Off and On links above to see the effect on the 18-135mm kit lens at wide angle and telephoto at maximum aperture. (Note that CA and distortion correction were also enabled for the "On" images above.) As you can see, there is significant corner shading at wide angle at maximum aperture, though it's fairly mild at full telephoto.

Lens corrections are supported for many Canon lens models, in both RAW and JPEG workflows. For JPEG shooting, the correction is made at capture time, while RAW shooters can access the function in Canon's Digital Photo Professional software. From the factory, the Canon 80D body ships with correction data for about 30 lens models. Canon's EOS Utility software allows correction data for lenses (including models as-yet unreleased) to be uploaded to the Canon 80D, and it appears some newer lenses can provide their own correction data to the camera body. When using third-party lenses, Canon recommends disabling lens corrections.

Accuracy
Very good accuracy from the optical viewfinder, excellent from the LCD in Live View mode.

We measured the Canon 80D's optical viewfinder's coverage at about 99%. This is a little short of Canon's 100% coverage specification, but still very good. Live View mode using the LCD in record mode was even more accurate, resulting in 100% coverage.