Underwater with the Canon RF 100mm Macro Lens and EOS R5

Underwater photographers have moved to the Canon EOS R-series in droves since 2020 and we now have a proper macro lens with the new RF mount.

The Canon RF 100mm f/2.8L Macro IS USM lens is the world's first medium telephoto macro lens with a maximum magnification of 1.4x. When combined with a camera featuring In-Body Image Stabilizer (IS) like the EOS R5, up to eight stops of shake correction IS is possible. Hybrid IS helps to compensate for angular and shift camera shake during macro shooting. Auto focus is quick, smooth, and quiet thanks to the dual nano USM technology. This is an L-series lens so it's packaged up in a rugged, dust and water-resistant design.

1/160 • f/10 • ISO 200 © 2021 Nirupam Nigam

Magnification

The old standard 100mm EF IS USM with adapter works quite well with newer full frame mirrorless cameras, but having a direct mount lens streamlines your gear and will provide better image stabilization and more control over spherical aberration. Most importantly, the lens also has a greater maximum magnification (1.4x compared to 1x) and shorter minimum focus distance (10.24" compared to 11.81").

"Compared to the Canon EF 100mm, the Canon RF 100mm macro is the obvious choice for Canon mirrorless shooters. In my opinion, the 1.4x reproduction ratio resulting in a super macro field of view is the most obvious advantage of the RF version of the lens. The extra zoom comes as a huge advantage if you want to take super macro photos without a diopter. The autofocus speed was slight faster than the EF lens with the EF-EOSR adapter, but not obviously so. If you already have the original EF macro and don't need the extra zoom, it may not be worth upgrading." - Nirupam Nigam, Underwater Photography Guide

1/160 • f/20 • ISO 200 © 2021 Nirupam Nigam

Physical Differences

Physically it's not a huge advantage to shooting without the adapter as the new RF lens is about an inch longer (25mm), a quarter inch larger in diameter (4mm), and a quarter pound heavier (105g). Some of the increase in size may be due to the addition of a customizable control ring that allows photographers to adjust exposure compensation, shutter speed, aperture or ISO. This ring is currently not accessible through the housing.

"In regards to the SA control ring - the ability to control the shape of your broken sounds good on paper but in practice it results in softer images. I don't think there are any underwater use cases that would appropriate for the SA control ring." - Nirupam Nigam, Underwater Photography Guide

1/160 • f/10 • ISO 200 © 2021 Nirupam Nigam

Availability

US market suggested retail price for the Canon RF 100mm f/2.8L Macro IS USM Lens is $1,399.00 and the lens became available in limited quantities at end of summer 2021. Watch for our review of the Canon RF 14-35mm f/4L IS USM Lens which is a great partner to the 100mm RF Macro.

1/160 • f/20 • ISO 200 © 2021 Nirupam Nigam

Canon EOS R5 100mm Macro RF lens Nirupam Nigam Ikelite Housing

1/160 • f/18 • ISO 200 © 2021 Nirupam Nigam

1/160 • f/20 • ISO 200 © 2021 Nirupam Nigam

1/160 • f/20 • ISO 200 © 2021 Nirupam Nigam

1/160 • f/20 • ISO 200 © 2021 Nirupam Nigam

1/160 • f/20 • ISO 200 © 2021 Nirupam Nigam

1/100 • f/9 • ISO 1000 © 2021 Nirupam Nigam

Nirupam Nigam is a dedicated underwater photographer and fisheries scientist. He is the Editor-in-Chief of the Underwater Photography Guide and the Marketing Director at Bluewater Photo. While growing up in Los Angeles he fell in love with the ocean and pursued underwater photography in the local Channel Islands. He received degrees in Aquatic and Fisheries Science and General Biology, at the University of Washington. Check out more of his photography at photosfromthesea.com and his reviews at uwphotographyguide.com and bluewaterphotostore.com!