Why Canon's EOS 250D Rebel SL3 Beats the 7D Mark II Underwater

Why Canon's EOS 250D Rebel SL3 Beats the 7D Mark II Underwater

Most modern DSLR and mirrorless cameras are capable of capturing great images underwater, but not all cameras are created equal once you put them into a housing. Upon its release in 2014, the Canon EOS 7D Mark II became a favorite among shooters looking for a high-quality, mid-range DSLR option. But since then, other cameras have cropped up that definitely give the 7D Mark II a run for its money underwater.

Investing in a Camera for Underwater

There are a lot of reasons to purchase a housing for the camera you already own. Typically it's the most economical choice, especially if you have an investment in lenses and/or lighting. But when comparing Canon DSLR cameras with APS-C sensors, there's an interesting caveat that warrants serious consideration. Read on to see why it's actually less expensive - and in so many ways better - to invest in a Canon SL3 system.

To be honest, we're not just picking on the 7D Mark II. These same arguments work against the EOS 50D, 60D, 70D, 80D, and the Rebel T-series.


The Canon SL Series

In 2013, Canon introduced its new SL line of DSLR's. The new design represented the world's smallest and lightest DSLR ever introduced. Unlike the EF-M mount mirrorless cameras at the time, the EOS 100D Rebel SL1 featured an optical viewfinder and standard EF lens mount just like the brand's more expensive professional grade DSLR cameras.

The size of the SL-series was actually considered too small by some land photographers, but turned out to be a huge advantage underwater. It allowed us to significantly trim the size and the cost of the corresponding housing.

The value is what really makes this system come together. The most basic system for the Canon EOS 7D Mark II will start at just over $2,500US once you add a dome port, vacuum pump, right handle, and spare o-rings. The comparable Canon Rebel SL3 system comes in about $200US less expensive including the camera body and 18-55mm lens! 

The most current model of the SL-series to date is the Canon EOS 250D Rebel SL3. We have shot this camera all over the world and here are the reasons we think it's the way to go over the EOS 7D Mark II and other Canon APS-C sensor DSLR cameras:

Canon Rebel SL3 size comparison Ikelite

The Canon Rebel SL3 is about the same size as any compact mirrorless camera like the Sony a6400 or Olympus E-M10 series. It's actually quite a bit smaller than other Canon Rebel series cameras like the T6i EOS 750D, T7i EOS 800D, or T8i EOS 850D.

1 | Camera Specifications

Some people can debate camera specs all day long. We love that the SL3 has a higher resolution sensor, 4K UltraHD video recording, an articulating LCD screen, and significantly better battery life. These specifications make it all around more enjoyable to shoot underwater and provide better results.


Canon Rebel SL3 (EOS 250D) Canon EOS 7D Mark II
Max resolution 6000 x 4000 5472 x 3648
Effective pixels 24 megapixels 20 megapixels
Sensor size APS-C APS-C
Articulated LCD Yes No
Touch screen Yes No
Flash X sync speed 1/200 sec 1/250 sec
Continuous drive 5.0 fps 10.0 fps
Video resolution Ultra HD 4K Full HD 1080p
Battery life (CIPA) 1070 670
449 g (0.99 lb / 15.84 oz)
910 g (2.01 lb / 32.10 oz)
122 x 93 x 70 mm (4.8 x 3.66 x 2.76)
149 x 112 x 78 mm (5.87 x 4.41 x 3.07)



2 | Size and Weight

The housing with port for the Canon Rebel SL3 is about half the size and weight of the comparable housing for the Canon EOS 7D Mark II. This creates significantly less drag underwater and makes it easier to handle, and easier to travel with. 


3 | Lens Mount

We already mentioned your investment in lenses, and Canon has some of the best glass on the market.  The ability to use all of your existing EF-mount lenses on the new camera body is something you won't necessarily get if you were considering a mirrorless camera instead. The kit lens 18-55mm is a great range for macro and semi-wide work.

Plus, you can add our favorite lens - the Tokina 10-17mm - for only about $450US plus a zoom gear. There is a little vignetting from 10-13mm but this can be corrected easily in post using Adobe® Lightroom or Photoshop. The SL3 housing doesn't accept all Canon lenses but it does accept the best EF-mount lenses to use underwater.


4 | Ergonomics

Something most people don't think about when choosing a camera is the ergonomics of the model underwater. Differences in camera layout are amplified when translated to a waterproof box. The Canon SL3 has an awesome control layout for underwater use, and access to the Q screen displays camera settings big, light, and bright on the rear LCD.

Canon Rebel SL3 quick settings display

Ever tried to read your exposure settings in the camera's viewfinder or on a tiny top LCD screen? Why not have them displayed bold and bright in between shots on the 3.0" rear LCD screen?

5 | Flash

The power of your strobes needs to constantly change as the distance to what you're shooting changes. This is necessary to avoid "blowing out" the subject - resulting in a bright, featureless blob of white - or under-exposing the subject - resulting in a photo that is dark with no color. The housing for the Canon SL3 incorporates built-in TTL circuitry. When an Ikelite DS strobe is attached, the camera is able to communicate through the circuitry and automatically adjust the strobe(s) power output based on the distance to your subject. 

This feature is also available on our 200DL and 50DL underwater housings, like that for the 7D Mark II, by adding the optional DL5 DS Link TTL Converter. The Canon SL3 is not compatible with non-Ikelite strobes - either in TTL or manual power - due to changes that Canon made to the flash hotshoe. 

Also, don't confuse TTL with "Auto" exposure mode. We still recommend shooting in "M" Manual mode on the camera so that you can adjust your aperture, shutter speed, and ISO while shooting TTL flash.

Shark Over Under Canon Rebel SL3 Ikelite Housing Strobes

Use M mode on your camera to manually adjust ISO, aperture, and shutter speed to properly expose the background- in this case the sunset. TTL flash will set your strobe power to light up the foreground subject correctly. When shooting sharks, turtles, rays, and other fast moving subjects it's impossible to manually adjust strobe power as quickly as your distance to subject is changing. 


6 | Set Up

The smaller lens diameters of the Canon 18-55mm and Tokina 10-17mm allow them to utilize a rear-loading zoom gear design. This makes camera set-up so easy, as you only need to open the back of the housing, attach the mount plate to the bottom of the camera, and slide the camera in.

Ready to see how it works? Check out our video tutorial:



7 | Back Up

The best part about buying a new camera to shoot underwater? You can use your old camera for surface shooting and leave the new camera inside of the housing. 


8 | Cost

The value is what really makes this system come together. The most basic system for the Canon EOS 7D Mark II will start at just over $2,500US once you add a dome port, vacuum pump, right handle, and spare o-rings. The comparable Canon Rebel SL3 system comes in about $200US less expensive including the camera body and 18-55mm lens!

The basic system for the Canon SL3 looks like this:

Canon Rebel SL3 Underwater Housing with Strobes Ikelite

Why not just add kick-ass strobes to offset the savings over a larger DSLR or full frame mirrorless system?



This is one of the few opportunities in life to get something better for less money. And with inflation at a high, we all need a little of that, don't we? 

We shoot every new camera on the market, and there are many great reasons why we keep coming back to the Canon SL3 as both a recommendation and something that we actively take out with us time and time again. We've had it all over the world in so many shooting scenarios and it often out-shoots even full frame systems (APS-C sensors actually have a big advantage in macro shooting). 

The proof is in the pudding: check out our ongoing SL-series gallery for all kinds of examples of what the system is capable of. 


Additional Reading

Canon SL-Series Photo Gallery

First Look Canon EOS Rebel SL3 250D Underwater Housing

Canon Rebel SL3 and Tokina 10-17mm Fisheye Underwater Photos

The Myth of TTL Strobe Exposure Underwater

The Next Generation of Professional Underwater Strobes


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The Ultimate Compact Underwater System | Setting up the Canon Rebel SL3 [VIDEO]
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