A 100mm f/2.8 macro lens has always been a classic, especially for macro and product photography. Released in 2009, the EF100mm f/2.8L Macro IS USM is a trusty staple in the bag of many photographers. How does the RF100mm f/2.8L Macro IS USM compare, and why should EOS R mirrorless camera users choose it? Read on to find out.

Introduction: Why do people love Canon’s 100mm f/2.8L macro lenses?

Introduction: The appeal of 100mm f/2.8L macro lenses

While they are best known for their macro photography capabilities, 100mm f/2.8 macro lenses are surprisingly versatile and well-suited to shooting objects that are larger or further away, including portraiture or even landscapes and architecture. Their key characteristics include:

- Life size (1:1) magnification (or more):  Achieves close-ups of tiny objects that escape the bare eye.

- Comfortable working distance: Sufficient space between the lens and subject to allow more light. Sensitive insects are less likely to be scared away.

- Faithful depictions: The 100mm focal length capture shapes and forms that look natural, which is ideal for product photography, portraiture, and beauty shots.

- Fast maximum aperture: At f/2.8, you get beautiful background blur (bokeh) and flexible exposure control under low light conditions.

- Professional grade: As L-series lenses, Canon’s 100mm f/2.8L macro lenses are built with high reliability, durability, and excellent optical quality, catering to the needs of photographers who use them to make a living.

EOS R5 + RF100mm f/2.8L Macro IS USM @ f/6.3, 1/100 sec, ISO 320

A 100mm macro lens is the perfect tool for creating fascinating close-ups.

Is RF the way to go?

Users of EOS R series mirrorless cameras have two options:

- EF100mm f/2.8L Macro IS USM (released 2009) with a mount adapter.
- RF100mm f/2.8L Macro IS USM (released 2021): This is the native lens designed for the EOS R mirrorless system.

Here is how they are different.

Difference #1: Closest focusing distances and maximum magnification

Difference #1: Closest focusing distances and maximum magnification

The RF lens focuses closer, achieving up to 1.4x magnification

The RF100mm f/f2.8L Macro IS USM is more than just a copy of the EF100mm f/2.8L Macro IS USM. Canon’s lens developers leveraged on the RF mount’s design flexibility to create a new lens from scratch. Two major new features made possible from this are:

- A shorter closest focusing distance of 0.26m (compared to 0.3m on the EF100mm f/2.8L Macro IS USM).
- A more-than-life-size maximum magnification ratio of 1.4x.

 

More room for focusing when shooting extreme close-ups

The shorter closest focusing distance on the RF100mm f/2.8L Macro IS USM means and extra 4cm allowance, so the camera still can focus even if wind, subject, or camera movement brings the subject closer to the lens than originally intended.

EOS R6 Mark II + RF100mm f/2.8L IS USM @ f/11, 1/125 sec, ISO 1000

Shot near the lens’ closest focusing distance. The extra allowance made it easier to keep the focus on this red ant as it moved around the swaying rattlebox plant.

 

Difference #2: Focusing and focus breathing

Difference #2: Focusing and focus breathing

The RF lens has faster, smoother autofocusing with less focus breathing

On macro lenses like the EF100mm f/2.8L Macro USM and RF100mm f/2.8L Macro USM, the focusing elements must move over a larger distance to be able to focus from close-up to infinity. Ensuring swift, seamless autofocusing is a technical challenge!

While the EF100mm f/2.8L Macro USM uses Ring USM to drive the autofocus, the RF100mm f/2.8L Macro USM adopts a new electronic floating focus control system where dual Nano USMs drive the floating and focusing lens groups separately. This ensures faster, more precise autofocus control even with the increased close focusing range.

Some of the effects of the new focusing system can be observed in the below videos, which show focus position movement during the focus bracketing function. For both videos, the lenses were used with the EOS R6 Mark II, and the camera was set to take 30 shots at an interval level of 6.

Focus bracketing on the EF100mm f/2.8L Macro IS USM

Focus Bracketing on the RF100mm f/2.8L Macro IS USM

Focal position changes on the RF100mm f/2.8L Macro IS USM appear smoother and less jarring, and there is less focus breathing. In comparison, the focus position movements and changes in angle of view are more visible with the EF100mm f/2.8L Macro IS USM. The RF lens is rated to reduce focus breathing by about 50% at 1.0x compared to the EF lens.

Focusing during video
Nano USM is noted for smooth, quiet focus transitions during video This, together with the reduced focus breathing, makes the RF100mm f/2.8L Macro IS USM better equipped for video.

Difference #3: SA Control Ring

Difference #3: SA Control Ring

Different bokeh styles, more creative possibilities

A large maximum aperture and long focal length are a classic combination for beautiful bokeh. The RF100mm f/2.8L Macro IS USM ‘s SA (Spherical Aberration) Control Ring takes this even further—you can now control how bokeh lights look.

EOS R6 Mark II + RF100mm f/2.8L IS USM @ f/2.8, 1/1600 sec, ISO 3200
Multiple exposure: 4 shots shot at SA -2, 0, and +2

The SA Control Ring unlocks a new frontier of creative exploration.

Difference #4: Image stabilisation

Difference #4: Image stabilisation

The RF lens maintains sharp shots at slower shutter speeds

What’s the same?

Both the EF and RF lenses are equipped with Canon’s in-lens Optical IS (Image Stabilizer) and Hybrid IS technology. Hybrid IS which corrects blurring from shift camera shake, which tends to be more prominent during macro shooting and cannot be corrected by traditional image stabilisation.

What’s different? – IS performance

On cameras with no In-Body IS, the EF100mm f/2.8L Macro IS USM provides up to 3.5 stops’ IS compared to up to 5 stops on the RF100mm f/2.8L Macro IS USM. On cameras with In-Body IS, Coordinated Control IS can provide up to 8 stops’ equivalent image stabilisation with the RF lens.

Our real-world tests show that the RF100mm f/2.8L Macro IS USM produces usable handheld shots consistently up to a shutter speed of 4 seconds, whereas the EF lens produced usable shots at up to 1 second.

EOS R6 Mark II + RF100mm f/2.8L Macro IS USM @ f/9, 4 sec, ISO 100

A handheld shot at 4 seconds on the RF100mm f/2.8L Macro IS USM. A tripod would be necessary to ensure usable results on the EF lens.

SNAPSHOT’s findings

We took multiple sets of handheld images with both lenses, working down from 1/125 seconds. Findings are as follows:

✓:  At least 50% of shots had no obvious camera shake even at 100%
△:  At least 60% of shots had minor camera shake. Not very visible at smaller resolutions (2048px or below)
×: Visible camera shake even at smaller resolutions

Shutter speed	EF	RF
1/125	✓	✓
1/60	✓	✓
1/30	✓	✓
1/15	✓	✓
1/8	✓	✓
1/4	△	✓
0.5	△	✓
1	△	✓
2	×	△
4	×	△
5	×	△

Difference #5: Controls and operating features

Difference #5: Controls and operating features

Better ease of operation on the RF lens

Both the RF and EF lenses have:

- An AF/MF switch
- An IS On/Off switch
- A focus limiting switch that provides 3 options for focusing ranges (full, mid-range to infinity, closest focusing distance to mid-range.)

Like all RF lenses, the RF100mm f/2.8L IS USM has a programmable control ring which serves as another physical control for exposure settings.

RF lens: Onscreen distance scale

The distance scale is a useful aid for focusing during macro shooting and manual focusing. While the RF lens has no physical distance scale, you can display it in the viewfinder or rear monitor—a function made possible by the more advanced RF mount communication system.

Other considerations

Other considerations

i) Size: Almost the same after factoring in the mount adapter

As seen in Difference #5, the EF100mm f/2.8L Macro IS USM alone is slightly shorter than the RF100mm f/2.8L Macro IS USM. However, this difference is practically negated after factoring in the EF-EOS R Mount Adapter, which is necessary for using EF lenses on EOS R series cameras.

	Dimensions
RF100mm	Approx. 81.5 x 148 mm, 730g
EF100mm	Approx. 77.7 x 123 mm, 625g
EF-EOS R Mount Adapter	Approx 71.2 x 24mm, 110g

ii) Image quality: The RF lens has less chromatic aberration

The EF and RF lenses correct these in different ways: one UD lens on the EF lens, and optimised glass and configuration on the RF lens. The lenses are on par in terms of sharpness and resolution, but as the following crops taken from an image corner show, chromatic aberration is better corrected on the RF lenses.

Know this: The EF and RF lenses correct these in different ways: one UD lens on the EF lens, and optimised glass and configuration on the RF lens.

 

RF100mm f/2.8L Macro IS USM: Sample images

EOS R6 Mark II + RF100mm f/2.8L Macro IS USM @ f/8, 1/125 sec, ISO 6400

EOS R6 Mark II + RF100mm f/2.8L Macro IS USM @ f/8, 1/125 sec, ISO 1600

EOS R5 + RF100mm f/2.8L Macro IS USM @ f/32, 1/160 sec, ISO 6400

EOS R5 + RF100mm f/2.8L Macro IS USM @ f/6.3, 1/100 sec, ISO 100

EOS R6 Mark II + RF100mm f/2.8L Macro IS USM @ f/2.8, 1/100 sec, ISO 1250/ SA Control Ring: +2