Canon RF 10-20mm Underwater Review [VIDEO]

Featuring Jean Rydberg

We love super wide angle lenses for shooting underwater because they allow us to get closer to our subject. Reducing the amount of water between your camera and what you’re shooting will increase the color and clarity of your photos and video.

Canon recently released the RF 10-20mm f/4L IS STM lens and we were excited to see what it’s capable of. Jean Rydberg breaks down how the lens performs underwater and takes a look at the results from Ikelite Ambassador Bill Hawthorne shooting the lens on his Canon EOS R6 Mark II in a 200DL Underwater Housing.

 
 

Sharpness and Distortion Underwater

This is a rectilinear lens and that comes with some issues when shooting behind a dome port underwater. Rectilinear lenses do not give you as sharp of images as fisheye lenses tend to do. When you shoot the 10-20mm, for best edge sharpness, you'll wanna shoot it behind a Full Size 8inch Dome and minimize your aperture to F/13 or even smaller if possible.

Compared to something like the popular 8-15mm fisheye, you will see more distortion in the corners when shooting with the 10-20mm lens.

 

Choosing a Dome Port

I mentioned the large diameter eight inch dome. You actually have two choices of dome port. There's the Full Size 8inch Dome and then there’s the Compact 8inch Dome which uses only a section of that full diameter hemisphere.

If corner sharpness is your top priority, or if you're shooting a lot of split-shots, you're gonna wanna go with that Full Size 8 inch Dome.

The Full Size 8 inch Dome provides the better edge sharpness and it's necessary to control the water line when shooting splits.

I do like to shoot the Compact 8 inch Dome because it's much easier to dive with underwater. It's got a lower profile and it's easier to swim with. So if I'm shooting big animals or models, I do like to go with the compact dome. And actually, the compact eight inch dome is only about half a pound, so often I end up traveling with both and switch them in and out depending on what I'm going to shoot.

The Canon RF 10-20mm lens is actually too large to fit into our DLM port system that we use for compact body cameras like the Canon EOS R8. For the R8, you'll probably wanna pick up that Canon 8-15mm fisheye, which is actually discontinued but you can still find them on the aftermarket.

If you're shooting a APS-C size sensor like the R7, the R10, the R100, check out the RF-S 10-18mm. It's a tiny, affordable lens and it's easy to set up and it really provides excellent edge sharpness when shooting with one of these crop sensor cameras.

Canon RF-S 10-18mm F4.5-6.3 IS STM Lens • F/9 @ 10mm © Douglas Klug

 

Video

If you're shooting a lot of video underwater, then that Canon 8-15mm is not going to cut it. It's not going to give you the image stabilization and the continuous autofocus that you need for great video.

You'll want to pick up an RF mount lens and the 10-20mm could be right for you in that scenario. It provides five stops of image stabilization which combines with the image stabilization that's in the camera body.

In Bill Hawthorne's footage of the Hellbender Salamander, the RF 10-20mm provides really smooth video without any post processing image stabilization needed.

 

Size and Build Quality

In terms of handling, this is an L-series lens which means it has a high end construction and it feels quite solid in your hand. It weighs only 1.25 lb and it's 3.3 inches in diameter and just about 4.4 inches in length.

The 10-20mm lens has a built-in hood that's non-removable and the focus and zooming mechanisms are inside the lens so you won't see it changing in length as you zoom the lens.

 

Who Should Buy It

If you were looking at, or already shooting, the EF 11-24mm lens, then I think this lens is for you. It's significantly smaller, lighter and way easier to handle. But it doesn't come cheap. It's retailing at $2,300 currently in the US. I do think the 10-20mm lens is a great choice if you're shooting a lot of models or perhaps big animal photography underwater.

If you're looking for something similar but more affordable in the rectilinear lens category, I recommend checking out the Canon RF 14-35mm F4 L lens, which we love. It does very well and it retails at only about $1,400.

"I found the performance of the RF 14-35mm f/4L to be as impressive underwater as it is in terrestrial settings and can easily recommend it for anyone looking to add a midrange RF lens to their kit." Canon RF 14-35mm F4 L Lens • F/8 @ 35mm © Austin Green

 

If you have any questions about shooting this lens or any lens underwater, shoot us an email at ikelite@ikelite.com and in the meantime, happy shooting!

 

Additional Viewing

A Review of the Canon RF 10-20mm for Underwater Photographers & Videographers

Wide Angle Showdown: Canon RF-S 10-18mm vs Tokina 10-17mm Underwater

Canon RF 14-35mm f/4L Lens Underwater Review [VIDEO] 

GET the Canon 8-15mm Fisheye Before It's GONE! // Underwater Review & Results

More Power, Smaller Package: Moving to Mirrorless with the Canon R7

Underwater Edge Sharpness Comparison Canon EF 8-15mm Fisheye vs Canon 10-20mm

 

  

Jean Rydberg is the President & CEO of Ikelite. She has lived her whole life in landlocked Indianapolis, Indiana, but is no stranger to the water as a daughter of Ikelite’s founder Ike Brigham. She has traveled around the world shooting and testing gear and enjoys new challenges in both photography and diving. Jean loves to learn about the creative ways photographers achieve their visions. More than anything she wants to show aspiring underwater photographers that excellence is attainable with any system. When she's not working she's spending time with her husband and two daughters.