Canon 11-24 /4L USM Lens Support & Testing

Canon 11-24 f/4 Lens Testing

This is an incredible lens, both in terms of wide angle field of view, and in how amazingly well the distortion is controlled at focal lengths this wide.  Canon has seriously upped their lens design game, and some of my favorite optics from any manufacturer (including Zeiss and Leica) are the 24-70 /2.8L II, 100mm /2.8L IS, and 8-15 /4.  Is 11-24 good enough to make that list? 

All of the parts needed to use 11-24 /f4L USM on 5D Mk III with zoom and focus control.

Nauticam was able to spin up a custom extension ring to support the very large diameter of this lens, as well as an updated version of the 230mm Glass Dome Port with a larger port opening, within just a few days of this lens hitting store shelves.  I got in the pool as soon as I could, and am happy to share some results here.

The assembled rig.  Notice focus & zoom control at the left handle, perfect for video use!

The assembled rig.  Notice focus & zoom control at the left handle, perfect for video use!

Gear Notes:

The lens is extremely large, and requires a new extension ring and dome port system that has a larger internal diameter.  The current system can accept lenses up to 98mm in diameter, and the new design used in 18812 and 21271 enables lenses up to 109.5mm to be used.  This is very exciting, as it also accommodates the previously incompatible, but fantastic Zeiss ZE and ZF.2 15mm /2.8 lenses!

Part No. Description Price
18812 230mm Optically Coated Glass Fisheye Dome Port (Larger Lens Opening for Canon EF 11-24/4) $2,050
21271 Extension Ring 70 with Focus Knob $680
19550 C1124-Z Zoom Gear for Canon EF 11-24mm f/4L USM $195
19551 C1124-F Focus Gear for Canon EF 11-24 f/4L USM $195
16315 RC1124-Z Zoom Gear for Canon EF 11-24mm f/4L USM in N120 Cinema Housings $220
16316 RC1124-F Focus Gear for Canon EF 11-24mm f/4L USM in N120 Cinema Housings $250

It is really important to have a frame of reference in mind when evaluating a lens this wide…  Corner softness is going to be a fact of life, and it can be controlled by stopping down, and keeping detail out of the corners.  You can also crop in post, or even better crop in camera by zooming in a bit in situations where you think soft corners might be distracting.  This is just an inevitable compromise associated with getting this wide without fisheye distortion.

My methodology here is to compare the lens to known quantities that are popular for underwater imaging, and simply determine if 11-24 is better or worse.    I’ll only compare like focal lengths, it just isn’t fair to compare 11-24 at full wide with a narrower lens.  This means that 11-24 wins by default at 11mm, as there is no other currently available non-fisheye lens that is this wide.  

Our test chart has been upgraded to a new, stiffer material that stays pretty flat in the water.  Occasionally water movement would flex the chart, and cause what appear to be uncharacteristic distortions.  This could influence some of the sharpness judgements as well, but in all the test shots I see that the corner performance is about equal on all four corners, which is acceptably accurate for me. 

Corner softness is the easiest defect that pops up behind a dome to detect, and you’ll see examples here.  The tests are done at f5.6, which is actually a pretty stressy aperture.  The results are dramatically improved by stopping down a bit. 

Canon 14mm /2.8L II

This is a lens I have always really wanted to like, but could never find the kind of in water corner performance I was after.  

This isn’t the greatest example, as there was clearly some flex in the chart that makes it appear that there is distortion that doesn’t actually exist.  Both shots exhibit some softness, even at this more distant reproduction.

Here are corner crops (well, zoomed in lightroom actually, then screen grabbed).   

And here is the same chart, from about a foot away.

with corner crops:

I think it is pretty safe to say that 11-24 is better, and better by a significant margin in the closer focusing situations.  

Canon 16-35 /2.8L II

This is probably the most popular wide angle lens commonly used with Canon full frame cameras, and is used in many stunning wide angle images.  Performance isn’t perfect, but the wide field of view and overall good image quality has made it very popular on full frame.  

And the corner crop:

And now the same lenses, but closer to the chart:

And corner crops:

This one really surprised me…  Neither lens has a Lightroom Lens Correction or CA adjustment applied, so these are straight out of the camera.  I can’t believe how much purple fringing is apparent in all of the 16-35 /2.8L II test, and how well controlled it is in 11-24.  I don’t see a tremendous difference in corner sharpness in either test.  Maybe 11-24 is a bit better? 

Performance at 11mm

And now, the moment we’ve all been waiting for.  There is nothing to compare 11-24 to at 11mm, so it will have to stand here on its own.  

Corner Crop

Close focus:

and Close Focus Corner Crop:

Corner softness certainly exists, but I’ve seen a lot worse! In situations where it is possible to stop down, or subjects are in blue water, I think the entire lens zoom range is usable.

Conclusions:

I’m very encouraged by these results.  I see that 11-24 is clearly better than Canon 14mm /2.8L II at 14mm, and as good or better at 16mm than 16-35 /2.8L II.  At 11mm, the angle of coverage is over 10 degrees wider than 14mm, and the ability to zoom out to 24mm is nice to have with skittish subjects or to crop out distracting backgrounds in camera.  There isn’t any distracting fisheye distortion, causing curved water surfaces or overly bulbous centered subjects.  Close focus is good enough for some interesting close focus wide angle shots, too!

Now, for some question and answers...

The results are good, but what are some potential issues?

Lens flare is also a reality with any optic this wide, and is something to be aware of in real world use.   The lens is big, heavy, and expensive.  24mm might not be long enough for skittish critters.

Is this a good choice for RED Dragon 6K? 

Yes, and I don’t know of a better wide angle optic for his camera in its 6k mode (slightly smaller than Full Frame 35).  16-35 and 8-15 /4L have been my favorites for this format in the past, but 8-15 induces fisheye distortion that needs to be managed in framing, and 16-35 just isn’t wide enough for a lot of wide shots.  11-24 is perfect!  Much of the corner smushiness in these shots won’t be apparent, falling outside of the recorded frame when shooting 6K.

Should I sell my 16-35 if I buy 11-24?

I’m not sure I’d run off and do that…  That range from 24-35mm is a pretty useful one, especially with skittish big animals.  16-35 also has a front filter thread, making it more useful for use with polarizers and neutral density filters for topside shooting. It is also a lot smaller…  11-24 will handle well in the water, but I can see a lot of situations where I wouldn’t want to carry it around topside.

I’m an APS-C, user, is this lens for me?

I’d say probably not for most…  It is probably a bit sharper overall than the Canon lenses like 10-22 /3.5-4.5 or 10-18 STM that are designed for the smaller APS-C sensor, but my feeling is that it is only slightly sharper.  Those lenses are a fraction the weight, and something like 1/6 the price of 11-24.