Canon RF-S 18-150mm f/3.5-6.3 IS STM Lens Micro-Review & Results

By Matt Dowse

"The versatility of the lens has been impressive—capable of shooting everything from macro to medium wide-angle."

When I purchased the Canon R7, it came bundled with the Canon 18-150mm lens. Initially, I thought this would just be a simple above-water travel lens, as I planned to use my Sigma 17-70mm as my primary medium underwater lens. However, after realizing the 17-70mm didn’t quite work with my setup, I began searching for a better solution.

Through some research, I discovered that the Canon RF 18-150mm lens could work with a +4 diopter in my Ikelite housing, paired with a 6 inch dome port. This was a game-changer for me! The versatility of the lens has been impressive—capable of shooting everything from macro to medium wide-angle. It's become my go-to lens since switching to the R7.

All images featured in this review were captured with my Canon R7, paired with an 18-150mm lens and a +4 diopter, in an Ikelite 200DLM Underwater Housing # 69746 with a 6 Inch Dome Port # 5516.16, 1.2 Inch Extension # 5516.65, and Zoom Gear # 5515.16. To enhance the lighting, I used DS160 Strobes # 40160 with custom-made snoots.

Threebar porcupinefish image taken by Matt Dowse with a Canon R7 + Canon RF 18-150mm lens inside an Ikelite Underwater Housing

Threebar Porcupinefish • 32mm • 1/200 • f/11 • ISO 320 © Matt Dowse

Autofocus

The autofocus has been fast and accurate, and I typically use it in spot focus mode, which delivers crisp, clean images.

Two eels image taken by Matt Dowse with a Canon R7 + Canon RF 18-150mm lens inside an Ikelite Underwater Housing

Eels • 50mm • 1/125 • f/16 • ISO 320 © Matt Dowse

Optimal Focal Range

I’ve noticed that the depth of field tends to shrink between 100mm and 150mm, similar to other macro lenses. However, I’ve found that the sweet spot for this lens is around 50 - 90mm, where the focus is sharp, and you can close to the subject.

Zanzibar whip coral image taken by Matt Dowse with a Canon R7 + Canon RF 18-150mm lens inside an Ikelite Underwater Housing

Zanzibar Whip Coral • 125mm • 1/80 • f/11 • ISO 100 © Matt Dowse

Drawbacks

There are a couple of drawbacks I’ve encountered. For one, I’m unable to take under-over (split shot) images due to the +4 diopter. And when zoomed to about 120mm+ the focus seems to shift slightly away from the dome port.

Image Gallery

Most of these shots were taken at my local shore dive sites around Newcastle, NSW, Australia (alternate locations noted in captions). We’re fortunate to have fantastic shore diving in this area. The visibility tends to be variable, with an average of about 5 meters (16 feet) most of the year. However, we can sometimes enjoy visibility of up to 25 meters (82 feet), though it can also dip down to as low as 1 meter (3 feet). Because of this, I often take close-up shots to minimize the amount of water between the camera and the subject.

Hermit crab image taken by Matt Dowse with a Canon R7 + Canon RF 18-150mm lens inside an Ikelite Underwater Housing

Cone Shell Hermit Crab • 70mm • 1/100 • f/11 • ISO 320 © Matt Dowse

Blenny inside hole image taken by Matt Dowse with a Canon R7 + Canon RF 18-150mm lens inside an Ikelite Underwater Housing

Brown Sabretooth Blenny • 100mm • 1/125 • f/8 • ISO 100 © Matt Dowse

Eel image taken by Matt Dowse with a Canon R7 + Canon RF 18-150mm lens inside an Ikelite Underwater Housing

Eel • 60mm • 1/100 • f/259 • ISO 320 © Matt Dowse

Hawkfish image taken by Matt Dowse with a Canon R7 + Canon RF 18-150mm lens inside an Ikelite Underwater Housing

Hawkfish • 59mm • 1/80 • f/11 • ISO 100 © Matt Dowse

Goniobranchus kuniei image taken by Matt Dowse using a Canon R7 + Canon RF 18-150mm lens inside an Ikelite Underwater Housing

Goniobranchus kuniei, image taken in Bali • 70mm • 1/100 • f/14 • ISO 250 © Matt Dowse

Two eels image taken by Matt Dowse using a Canon R7 + Canon RF 18-150mm lens inside an Ikelite Underwater Housing

Eels • 92mm • 1/80 • f/11 • ISO 100 © Matt Dowse

Scorpionfish image taken by Matt Dowse using a Canon R7 + Canon RF 18-150mm lens inside an Ikelite Underwater Housing

Scorpionfish • 30mm • 1/60 • f/18 • ISO 125 © Matt Dowse

Cuttlefish image taken by Matt Dowse using a Canon R7 + Canon RF 18-150mm lens inside an Ikelite Underwater Housing

Cuttlefish • 50mm • 1/125 • f/16 • ISO 125 © Matt Dowse

Pufferfish image taken by Matt Dowse using a Canon R7 + Canon RF 18-150mm lens inside an Ikelite Underwater Housing

Pufferfish • 44mm • 1/100 • f/11 • ISO 320 © Matt Dowse

Mantis shrimp image taken by Matt Dowse using a Canon R7 + Canon RF 18-150mm lens inside an Ikelite Underwater Housing

Mantis shrimp, image taken in Bali • 84mm • 1/100 • f/14 • ISO 250 © Matt Dowse

Nembrotha nudibranch image taken by Matt Dowse using a Canon R7 + Canon RF 18-150mm lens inside an Ikelite Underwater Housing

Nembrotha • 62mm • 1/80 • f/11 • ISO 100 © Matt Dowse

Pancake shrimp image taken by Matt Dowse using a Canon R7 + Canon RF 18-150mm lens inside an Ikelite Underwater Housing

50mm • 1/100 • f/22 • ISO 320 © Matt Dowse

Anemone hermit crab image taken by Matt Dowse using a Canon R7 + Canon RF 18-150mm lens inside an Ikelite Underwater Housing

Anemone hermit crab • 70mm • 1/80 • f/11 • ISO 100 © Matt Dowse

Porcupinefish image taken by Matt Dowse using a Canon R7 + Canon RF 18-150mm lens inside an Ikelite Underwater Housing

Threebar porcupinefish • 47mm • 1/100 • f/13 • ISO 320 © Matt Dowse

Anemone image taken by Matt Dowse using a Canon R7 + Canon RF 18-150mm lens inside an Ikelite Underwater Housing

Anemone • 92mm • 1/125 • f/16 • ISO 125 © Matt Dowse

Jetty with light rays and school of fish image taken by Matt Dowse using a Canon R7 + Canon RF 18-150mm lens inside an Ikelite Underwater Housing

Little beach jetty • 18mm • 1/80 • f/7.1 • ISO 100 © Matt Dowse

Cuttlefish • 62mm • 1/100 • f/16 • ISO 320 © Matt Dowse

Nudibranch image taken by Matt Dowse using a Canon R7 + Canon RF 18-150mm lens inside an Ikelite Underwater Housing

Nudibranch • 59mm • 1/100 • f/14 • ISO 250 © Matt Dowse

Horned blenny image taken by Matt Dowse using a Canon R7 + Canon RF 18-150mm lens inside an Ikelite Underwater Housing

Horned blenny • 64mm • 1/100 • f/16 • ISO 320 © Matt Dowse

Coral banded shrimp image taken by Matt Dowse using a Canon R7 + Canon RF 18-150mm lens inside an Ikelite Underwater Housing

Coral banded shrimp • 32mm • 1/125 • f/18 • ISO 320 © Matt Dowse

Hinge-beaked prawn image taken by Matt Dowse using a Canon R7 + Canon RF 18-150mm lens inside an Ikelite Underwater Housing

Batfish image taken by Matt Dowse using a Canon R7 + Canon RF 18-150mm lens inside an Ikelite Underwater Housing

Seahorse image taken by Matt Dowse using a Canon R7 + Canon RF 18-150mm lens inside an Ikelite Underwater Housing

Rock cod image taken by Matt Dowse using a Canon R7 + Canon RF 18-150mm lens inside an Ikelite Underwater Housing

Underwater worms image taken by Matt Dowse using a Canon R7 + Canon RF 18-150mm lens inside an Ikelite Underwater Housing

Pancake nudibranch image taken by Matt Dowse using a Canon R7 + Canon RF 18-150mm lens inside an Ikelite Underwater Housing

Lionfish image taken by Matt Dowse using a Canon R7 + Canon RF 18-150mm lens inside an Ikelite Underwater Housing

Dwarf Hawkfish image taken by Matt Dowse using a Canon R7 + Canon RF 18-150mm lens inside an Ikelite Underwater Housing

Matt Dowse is an electrician, diver, and underwater photographer. He has been diving since 1990 and completed his PADI Divemater's course in 2008. He's been a Canon DSLR 7D shooter since 2010 and recently upgrade to the Canon R7 mirrorless system which he pairs with the Ikelite DS160 dual strobes. When he's not traveling to dive you can find him at the Swansea Bridge. Follow Matt on Instagram @matt.d71, watch Matt and his colleague Pete's underwater videos on their YouTube channel, Vimeo, or check out Matt's Redbubble page.

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