Canon 100mm f/2.8 Macro EF-Mount Lens {52}

Canon's 100mm f/2.8 macro prime, the EF workhorse for true 1:1.

At 1:1 maximum magnification, this lens reproduces subjects at true life size on the sensor. The 100mm focal length gives you a working distance that keeps you far enough from your subject to avoid blocking light or startling insects, a practical advantage over shorter macros. Internal focusing means the barrel stays the same 119mm length throughout the focus range, so a front-mounted ring flash sits at a fixed distance from your subject regardless of how close you get.

The ring-type USM motor is fast by macro standards and nearly silent, with full-time manual override available at any point without switching modes. A focus distance limiter cuts the hunt range down to 0.25x and beyond, which matters when you're shooting at normal portrait distances and don't need the lens cycling through the entire macro range to acquire focus. Eight aperture blades sit between f/2.8 and f/32, giving you reasonable out-of-focus rendering at wider apertures when you want subject separation than depth.

Optical performance across the focus range is consistent and flare resistance is strong even with direct light sources in frame. At close focus distances, corner shading is not a meaningful concern even on full-frame bodies. This is a lens that has been a reliable choice for working photographers across Canon EOS digital and film bodies for over two decades, and it adapts to Sony E, Canon RF, Nikon Z, Fuji X, and L-Mount systems with the appropriate third-party adapters.

Who It's For

Macro photographers shooting insects, botanical subjects, or small product work benefit directly from the 31cm minimum focus distance and 1:1 magnification without needing extension tubes. Portrait photographers get a flattering 100mm field of view at f/2.8 with a silent USM motor that won't distract subjects. Scientific and medical photographers who need accurate reproduction ratios will find the distance scale and depth-of-field scale genuinely useful in the field. Film and digital Canon EOS shooters with existing EF systems can slot this lens in without any additional hardware.

Key Features

• 1:1 maximum magnification for true life-size reproduction
• 100mm focal length provides 3.7-inch working distance at macro
• Ring-type ultrasonic (USM) motor with near-silent operation
• Full-time manual focus override available at any focus point
• Internal focusing keeps barrel at constant 119mm length
• Focus distance limiter restricts focus range to 0.25x magnification and beyond
• 8-blade diaphragm, f/2.8 to f/32 aperture range
• 12 elements in 8 groups with strong flare resistance

FAQ

What's the working distance at 1:1?

At maximum magnification, you're about 3.7 inches (94mm) from the front of the lens to your subject, which puts the sensor plane roughly 4.7 inches back. That's far enough to avoid blocking light or startling insects, and it lets you mount a ring flash at a fixed distance regardless of focus position.

How fast is the autofocus for macro work?

The ring-type USM motor is nearly instantaneous on current Canon bodies, especially compared to other macro lenses. The focus distance limiter is the key advantage - set it to 0.25x and beyond, and the motor won't waste time hunting through the entire focus range when you're shooting at normal distances.

Does this lens work on mirrorless cameras?

The EF mount version requires an adapter for Sony E, Canon RF, Nikon Z, Fuji X, or L-Mount systems. Third-party adapters are widely available and work reliably, though you lose autofocus on some systems depending on the adapter quality and camera body.

What's the corner shading like wide open on full-frame?

At f/2.8 at infinity there's a slight falloff on full-frame bodies, but it's gone completely by f/4. At 1:1 magnification, there's no meaningful corner shading even at f/2.8, so close-focus macro work is clean corner to corner.

How does the internal focusing design affect flash photography?

The barrel stays at 119mm length throughout the focus range, so a ring flash mounted on the front maintains a constant distance from your subject whether you're at infinity or at 1:1. This consistency simplifies exposure metering and flash positioning.

Is there any distortion I should worry about?

At macro distances, there's effectively no distortion. At infinity, there's a slight barrel distortion around 15-20 feet on full-frame bodies, but it's minor and only matters for critical work with straight lines. Macro subjects simply don't trigger this issue.

How resistant is this lens to flare?

Flare resistance is strong enough that you'd need to deliberately push exposure abnormally high and angle toward bright light sources to trigger visible artifacts. Direct sunlight in frame causes no practical flare under normal shooting conditions.