Points in Focus Photography

Canon EF 16-35mm f/4L IS USM Review

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Ultra wide angle rectilinear lenses are one of my favorite playgrounds for creative photography. The extremely wide angle of view introduces distortion to the image that is completely foreign from who we normally see the world. That effect can be put to creative use in many ways: from simply capturing more of the environment in a single image, to transforming the mundane into something that’s truly bizarre and interesting.

EF 16-35mm f-4L IS USM

For the longest time Canon’s full-frame ultra-wide-angle zoom lens situation was carried by the EF 16–35mm f/2.8L USM and the EF 17–40mm f/4L USM lenses. The choice between the two largely came down to picking whether you needed the faster aperture for active subjects, or couldn’t afford the f/2.8 lens.

However, in the grand scheme of things, neither were really great options. Both suffer from soft corners and other image quality maladies. Until recently, Canon’s wides have been the weakest part of their lens lineup. They’re certainly passable, but they’ve never shown the real brilliance that, say, Nikon’s wides have.

The EF 16–35mm f/4L IS USM changes the Canon wide-angle lens story—for the better.

Build

Size and weight aren’t the best indicators of build quality, but combined they can shed some light on how well something is built. Even though the EF 16–35mm f/4L IS USM sheds a stop of aperture and has the same number of elements and group as the EF 16–35mm f/2.8L II USM (16 elements in 12 groups), the size and weight are very close to those the faster lens.

The diameter and length of this lens is 3.25 x 4.44 inches (82.6 x 112.8 mm), compared to the f/2.8L II’s 3.5 x 4.4 inches (88.5 x 111.6 mm). Weight wise, the EF 16–35mm f/4L IS USM weighs 21.7 ounces (615 g), compared to the f/2.8L II’s 22.4 ounces (635 g). So the EF 16–35mm f/4L IS USM is slightly smaller in diameter and slightly longer, and just under an ounce lighter (0.7 ounce to be exact).

The EF 16-35mm f/4L IS USM (left) next to the EF 16-35mm f/2.8L II USM (right).
The EF 16-35mm f/4L IS USM (left) next to the EF 16-35mm f/2.8L II USM (right).

Side by side there’s really not much of a difference between the two lenses in weight or size. Actually, in some ways the f/2.8 lens looks, a little trimmer as it’s thinner for the majority of its length and only flares out at the end. The most noticeable differences in size are in the front filter ring and the new hood.

The EF 16–35mm f/4L IS USM follows the most common design for ultra-wide-angle zooms. Instead of having an barrel that extends when you zoom, all the moving parts are contained inside a singled outer barrel. However, unlike say a 70–200mm zoom, the front element of the EF 16–35mm f/4L IS USM moves when zoomed.

Front Element w/ Zoom (16mm)
Front Element w/ Zoom (16mm)
Front Element w/ Zoom (20mm)
Front Element w/ Zoom (20mm)
Front Element w/ Zoom (24mm)
Front Element w/ Zoom (24mm)
Front Element w/ Zoom (28mm)
Front Element w/ Zoom (28mm)
Front Element w/ Zoom (35mm)
Front Element w/ Zoom (35mm)

The overall build quality is quite spot on for a Canon L lens. The finish is the same hard black textured finish that Canon has been using for years. In my experience, the finish is highly resistant to marring and scratching and seems to be quite durable.

I can’t precisely identify the material of the outer lens barrel, or at least the few ares that aren’t rubber grip covered control rings. Tapping on it sounds like plastic or maybe very thin metal. Either way, it sounds the same as my EF 16–35mm f/2.8L II USM or my EF 24–70mm f/2.8L USM to my ear, and both those lenses are quite durable so I would expect the EF 16–35mm f/4L IS USM to be the same.

The filter threads and hood mount appear identical in material and finish to those on the EF 16–35mm f/2.8L II USM. Again, I’m not entirely sure what that material is; however, if it’s the same as the material on the EF 16–35mm f/2.8L II USM, I’m not expecting any issues.

Weather Sealing

The EF 16–35mm f/4L IS USM, like the rest of its L contemporaries, is designed to be resistance to dust and water intrusion. Quoting from the manual:

Tight seal structure ensures excellent dustproof and drip-proof performance.

Since the front element moves when zooming, you need to attach a Canon PROTECT filter sold separately for adequate dust- and water-resistant performance. Without a filter, the lens is not dust and water resistant.

The short of it here, is that as long as you have a protective filter on the lens you’re good to go against drops and dust. I should also point out that while Canon suggests using their PROTECT filters, their 77mm PROTECT filter is 5mm thick and will cause more vignetting issues than a slim 3rd party alternative (see the filters section for more details).

The most visible indication of weather sealing is, of course, the black gasket around the outside of the lens mount.

All told, I don’t see any glaring issues where the weather resistance of this lens should be any worse than the resistance of any other Canon L lens.

Hood

Hoods on wide and ultra-wide angle lenses generally aren’t good for much in the way of protection or shading. The angle of view they have to deal with is just too wide for the hood to be very deep. Interestingly, the EW–82 hood for this lens doesn’t seem nearly as useless as say the hood for the EF 16–35mm f/2.8L II USM or the EF-S 10–22mm f/3.5–4.5 USM, perhaps because it doesn’t flare out so dramatically. That said, it’s still not going to offer a lot of protection to the front element.

EW-82 hood
EW-82 hood

The biggest upgrade point in the hood is that it uses Canon’s current push button locking hood design instead of the old friction fit method. Friction locks have always given me trouble eventually. As time goes on, the locking nibs and the lens’s bayonet mount wear and the lock becomes looser. I have some lenses, where ultimately I have to gaffer tap the hood in place to keep it from falling off at an inopportune time. The button lock eliminates that wear issue completely, and it’s going anywhere unless you hit the release button.

EW-82 Hood Lock mechanism
EW-82 Hood Lock mechanism

This hood, as well as the other button locked Canon hoods, doesn’t have a preferred orientation. The locking mechanism will secure the hood properly regardless of which orientation or whether the hood is in the stowed or use positions.

The hood is narrow enough to fit in most camera bags, unlike the extra wide hoods for the EF 16-35mm f/2.8L II USM.
The hood is narrow enough to fit in most camera bags, unlike the extra wide hoods for the EF 16-35mm f/2.8L II USM.

The other place where the EW–82 hood stands out as being excellent is stowed in the bag. I know it sounds weird, but compared to the EW–83 hood from the EF 17–40mm f/4L USM and EF-S 10–22mm f/3.5–4.5 USM, or the EW–88 of the EF 16–35mm f/2.8L II USM; the hood on this lens just fits in every bag I own better. Again, I attribute this largely to the lack of significant flare in the design.

One final nice feature of the hood is that the two largest pedals are flat, so you can sit the lens on end on the hood and it will stand up instead of tipping over like the EF 16-35mm f/2.8L IS USM did.

Filters

Filters are certainly something that’s decorated in usage with the rise of digital photography and the associated processing it enables. However, while some filters can be eliminated on account of technology, such as color correction, there are still effects that are best done with filters instead of software. Polarization, long exposures, and diffusion are the big 3 that come to mind.

For the most part, talking about filters is a waste of time. On most lenses, the angle of view is narrow enough that even thick filters or stacks of filters, won’t cause any noticeable vignetting. Ultra-wide-angle lens, however, is one big case where that isn’t true. The wide angle of view combined with the typically tight tolerances makes filter driven vignetting a real concern.

Since the filter ring is part of the outer lens barrel, the 77mm filter mount on the EF 16–35mm f/4L IS USM doesn’t move or rotated when the lens is zoomed or focused. This of course is expected of ra professional grade lens, and it means creative filters such as split ND grads and polarizers can be used easily.

Moreover, the 77mm mount means the EF 16–35mm f/4L IS USM shares a common filter size with most of Canon’s L zooms. The exception is the 82mm of the EF 16–35mm f/2.8L II USM and EF 24–70mm f/2.8L II USM, and the 67mm filters of the EF 70–200mm f/4L USM and EF 70–200mm f/4L IS USM.

That said, thick filters are certainly problematic on ultra-wide-angle lenses. A standard 5mm thick protection filter, or 7mm thick polarizer will vignette on the lens noticeably when it’s zoomed to 16mm. A thin, 3mm, protection filter, like the B+W XS-Pro series, works much better.

The filter vignetting situation extends to the polarizers too. While polarizers aren’t as useful with ultra-wide angle lenses due to the differential darkening they create in skies, they still can be useful in removing shine from leaves and reflections from water in scenes without sky in them. The filter vignetting situation still applies though, and a thin polarizer is necessary — again, something like the 5mm thick B+W XS-Pro — will help minimize corner vignetting. Though even at 5mm there will still be vignetting at 16mm form the filter.

Rectangular Filter Systems

For creative effects, including neutral density and ultra-wide angle lenses can be problematic. Serious users typically use 4 inch (100mm) wide filters from the likes of Lee or Cokin. For most lenses, these are wide enough to not have the holders show up in the periphery of the frames. However, when you get down around 16mm, the angle of view is wide enough to start revealing the holder unless extreme caution is taken.

At 16mm a Lee wide-angle adapter mounted directly to the lens will show some vignetting, but it’s slight enough to be acceptable in my opinion. Moreover, with only two slots in the holder, there’s some corner issues when the slots are rotated about 30° to the long axis of the frame.

16mm No Filter
16mm No Filter
16mm Lee Wide Angle Adapter
16mm Lee Wide Angle Adapter
16mm Lee Wide Angle Adapter + 2 slots at 0 deg
16mm Lee Wide Angle Adapter + 2 slots at 0 deg
16mm Lee Wide Angle Adapter + 2 slots at 30 deg
16mm Lee Wide Angle Adapter + 2 slots at 30 deg

With a thin protection filter in place, the vignetting situation deteriorates some but not as much as I had expected. The most obvious place where things go really south is when the Lee holder is rotated out of alignment with the long eye of the frame, where there is extremely noticeable clipping.

16mm B+W XS-Pro UV
16mm B+W XS-Pro UV
16mm B+W XS-Pro UV + Lee Wide Angle Adapter
16mm B+W XS-Pro UV + Lee Wide Angle Adapter
16mm B+W XS-Pro UV + Lee Wide Angle Adapter + Holder @ 0 deg
16mm B+W XS-Pro UV + Lee Wide Angle Adapter + Holder @ 0 deg
16mm B+W XS-Pro UV + Lee Wide Angle Adapter + Holder @ 30 deg
16mm B+W XS-Pro UV + Lee Wide Angle Adapter + Holder @ 30 deg

 

All that said, there is one very important caveat to keep in mind here. I do my vignetting testing at the focal length that nets the widest apparent angle of view. In the case of the EF 16–35mm f/4L IS USM, the field of view appears to be the widest at the close focus distance. In the end, this shows the worst case vignetting, but probably isn’t all that indicative of what you can normally expect to see when focusing at infinity or some where closer to that.

With that in mind, the image below takes the last of the previous cases, a 3mm XS-Pro filter + the Lee wide-angle ring + a 2 slots in the lee filter mount rotated about 30°, and shows the interference when the lens is focused at infinity.

This is the same arrangement as the last XS+Pro + Lee holder stack, only this time I've focused the lens at infinity.
This is the same arrangement as the last XS+Pro + Lee holder stack, only this time I’ve focused the lens at infinity.

Handling, Zoom and Focus

The EF 16–35mm f/4L IS USM follows the standard design for professional zooms, there are two control rings, one for focus and the other for zoom. These two rings are largely equal in size, and the focus ring placed at the front of the lens and the zoom ring place close to the lens mount.

Personally, I find this arrangement less than idea. I find the rear positioning of the zoom ring means I end up choking up on my grip which reduces my ability to maximize my stability when holding the camera. Moreover, I find I frequently end up bumping the focus ring accidentally while trying to adjust my grip to maximize my stability and comfort. I find the problem is compounded on ultras-side angle zooms, as they tend to have the zoom ring even closer to the mount than mid-range professional zooms do.

All told, I’m increasingly finding that I would prefer to have the zoom and focus rings reverse while maintaining the same nearly equal sizes.

Focus Ring

The focus ring on the EF 16–35mm f/4L IS USM is the forward most control ring on the lens. Overall it’s 1–3/8 inches wide with 1–1/8 inch of that rubberized.

EF 16-35mm f/4L IS USM Focus Ring
EF 16-35mm f/4L IS USM Focus Ring

The entire rotation of the focus ring is a mere 90° or so. However, focusing from 3 feet to infinity is a mere 5 or so degrees.

Since this is a mechanically coupled ring-USM lens, full time manual focus is always available.

Moreover, like other mechanically coupled ring-USM lenses, the focus ring will rotate indefinitely even after the focusing elements have reached the extent of their travel. Typically I find you can detect this while focusing as there will be a slight click or bump at the extent of travel, and a slight increase in rotating resistance. Though the effect is subtle.

Zoom Ring

The zoom ring on the EF 16–35mm f/4L IS USM is the rear most ring, and it’s situated right next to the lens mount. Overall it’s 1 inch wide, with 3/4 inch of a rubberized ring grip.

Zoom ring, distance scale, and focal length index marks.
Zoom ring, distance scale, and focal length index marks.

The ring on my lens is smooth and well damped. Compared to my copy of the 16–35mm f/2.8L II USM, the zoom action is much more uniform in both directions and relative to the angle of the lens. There’s no appreciable change in force needed to change the focal length regardless of whether the lens is pointing up, down, or is parallel to the ground.

Other Controls and Distance Scale

The EF 16–35mm f/4L IS USM doesn’t have an awful lot in the way of controls beyond the focus and zoom ring. There are two control switches, one of the AF system and one for the image stabilizer.

Mode Switches
Mode Switches

Since this is a ring-USM lens, it’s capable of full time manual focus. Therefore the AF switch is really only needed as a safety to disable the AF system completely when the AF is tied to the shutter release. Alternative, if you use rear button focusing, you can get away without ever taking the AF/MF switch out of AF unless you absolutely need to insure that the camera can’t alter the focus.

The second physical switch is the STABILIZER switch, which control the image stabilization system. The EF 16–35mm f/4L IS USM lens’s Image Stabilization system doesn’t provide user selectable modes — panning is detected and compensated for automatically — so there is only settings for turning the IS system on and off.

Finally there is a distance scale located on the top of the lens. It’s graduated in feet and meters, and like most ultra-wide angle zooms nearly useless for anything more than the vaguest notion of the focus distance. There is no depth of field scales or any other useful information on the distance scale, aside from a 16mm IR focusing compensation mark.

Personally, I’ve long since felt that traditional distance scales like the one on the EF 16–35mm f/4L IS USM have outlived their usefulness. An electronic replacement tied into the camera or through a display on the lens could provide far more information to the photographer than what can be conveyed through the scales currently used, especially on ultra-wide angle lenses.

Image Stabilization

This is the first ultra-wide angle zoom that I’ve worked with that is image stabilized. Canon advertises that the IS system is good for up to 4 stops of shutter speed when compensating for camera shake at 35mm. At shorter focal lengths, the IS system may be less effective.

The loss of IS “performance” is a byproduct of the extremely long exposures that would be cropping up with ultra-wide-angle lenses. Consider that using the handholding rule of thumb speed for 16mm (1/20s), 4 stops of IS would mean shooting for 0.8s.

I’m not even going to bother trying to quantify the performance that I’ve seen. The effectiveness of image stabilization is highly dependent on the photographer holding the camera and lens. The reality is how well an IS system ultimately works for any given photographer is going to depend heavily not only on their inherent stability, but also on their footing, stance, and technique.

As an example of this, Bryan Carnathan of the Digital Picture in his review reported reliably getting sharp frames at 1 and 2 seconds. I can’t even come close to matching that unless I focus a tremendous amount of energy on my breathing and technique. Even then, I often end up with blurred exposures from the simple act of pressing the shutter release, no matter how carefully I do it.

That said, the following images are an example of what the IS system is capable of when everything else lines up right.

IS OFF, 0.6s f/4 ISO 400 at 35mm
IS OFF, 0.6s f/4 ISO 400 at 35mm
IS ON, 0.6s f/4 ISO 400 at 35mm
IS ON, 0.6s f/4 ISO 400 at 35mm

In the broad picture, the IS system seems to do its job. In the informal testing I did conduct, I did see improved sharpness in images at shutter speeds below those suggested by the hand holding rule of thumb with the IS system enabled. Especially when shooting at 35mm as show in the 0.6s examples show above. However, at 16mm my success at such low shutter speeds is somewhat less consistent.

That said, when you start talking about shutter speeds in the 1/2 second range, there is no easy solution for sharp images without a tripod. You absolutely must have the best technique possible, and even then, you will likely move enough in the directions that the camera can’t compensate for (roll and fore–aft) that you’ll end up with motion blur in your images.

Finally a comment on IS modes and tripod detection. Most longer focal length stabilized lenses have a mode selection switch to select from static, panning, and now erratic tracking modes. This lens does not, and according to Canon it doesn’t need one either.

According to Canon[1] the lens will automatically detect if it’s being used in a panning situation and automatically switch to only compensating orthogonally to the direction of the pan.

The question of tripod detection is a bit more complicated. According to Canon’s Professional network page on image stabilization the EF 16–35mm f/4L IS USM does not detect if it’s on a tripod. However, according to the CPN product page under “Key Benefits”, Canon says the following.

It also includes tripod detection, switching off IS automatically when the camera is mounted on a tripod for optimum image quality.

The manual for the lens seems to support that position in a slightly round about way saying:

Set the STABILIZER switch to OFF when you are taking pictures with the Bulb setting (long exposures). If the STABILIZER switch is set to ON, the image stabilizer may introduce errors.

When you use a tripod, the Image Stabilizer should be turned off to conserve power.

You definitely will want to turn the IS system off if you’re shooting long exposures from a tripod, if only for the power saving reasons. For more normal exposures, say down to 1 second or so, shot from a tripod, I’ve not yet had a problem with leaving the IS system on. Though if I’m exclusively working from a tripod, I’ll still turn the IS system off again for the power conservation reasons.

Optical Performance

Quantitate analysis of lens performance is something I’m still not setup to do. However, I feel remiss for not at least taking a qualitative approach to the aspects I can address. If you’re looking for resolution numbers, I recommend DXOMark for that.

The good news is that this lens clearly demonstrates that Canon does get how to design and build wide and ultra-wide angle lenses. This has always been Canon’s weak area in lens design. The EF 16–35mm f/4L IS joins the recent collection of really good Canon wides, and is the first really good Canon wide zoom.

In fact, the not so insignificant increase in image quality — especially in the corners — is the only reason I switched from EF 16–35mm f/2.8L II USM to this lens. The good news is that it doesn’t take a resolution test chart to see the different in performance between this lens and it’s faster older sibling. The corners are considerably sharper.

Moreover, for night landscape photographers, coma is significantly better than EF 16–35mm f/2.8L II USM.

Stars make a great test for coma, and the EF 16-35mm f/4L IS USM does a good job at controling it as show in this corner frame crop. Notice that the stars are effectively point sources in this 4s exposure.
Stars make a great test for coma, and the EF 16-35mm f/4L IS USM does a good job at controlling it as show in this corner frame crop. Notice that the stars are mostly point sources in this 4s exposure.
This is nearly the same scene as show in the f/4L test for coma, but shot with the EF 16-35mm f/2.8L II USM, with the same exposure time (4s), note the streaking of the stars due to coma.
This is nearly the same scene as show in the f/4L test for coma, but shot with the EF 16-35mm f/2.8L II USM, with the same exposure time (4s), note the streaking of the stars due to coma.

While there are still some coma, especially in the extreme corners, it’s much better than it was in the EF 16-35mm f/2.8L II USM.

Coatings and Flare

While Canon has a number of interesting and highly sophisticated nano-scale coatings, none appear have been used on the EF 16–35mm f/4L IS USM. What’s even more surprising is that even without the fancy coatings, the lens controls flare extremely well.

The other coating related point is that the outside surfaces of the front and rear elements are coated with an oleophobic fluorine based coating. Canon first started using this coating on their sensors to help reduce dust spots by causing oils to not stick to the sensors. They’ve since carried the technology to their lenses where it aids in helping keep the front and rear lens surfaces cleaner: making them less susceptible to smudging and finger prints.

Parfocal Stability

A lens is considered to be parfocal when the focus position doesn’t change when the lens’s zoom position is changed. This trait is desirable for video users as it allows them to zoom without having to refocus. For still photographers, the utility of a parfocal lens has largely been diminished by autofocus, and as such most modern still lenses aren’t designed to be parfocal.

Parfocal or not, it doesn’t really matter that much with the EF 16–35mm f/4L IS USM at normal working distances. As a wide to ultra-wide angle lens, there’s so much depth of field to work with that it’s almost impossible to notice any errors in focusing, even wide open at f/4.

16mm 35mm
Parfocal test 16mm to 35mm, 100% crop at 16mm.
Parfocal test 16mm to 35mm, 100% crop at 16mm.
Parfocal test 16mm to 35mm, 100% crop at 35mm.
Parfocal test 16mm to 35mm, 100% crop at 35mm.

16mm 35mm
Parfocal test 35mm to 16mm, 100% crop at 16mm.
Parfocal test 35mm to 16mm, 100% crop at 16mm.
Parfocal test 35mm to 16mm, 100% crop at 35mm.
Parfocal test 35mm to 16mm, 100% crop at 35mm.

The above two images show the results focusing at 16mm and 35mm respectively, and then zooming to the other extreme. For those tests that subject distance was about 6 feet.

Breathing/Focus Focal Length Stability

The other video-centric consideration with lenses is breathing. Many inner and rear focusing lenses change focal length when they’re focused closer to the camera. In videography and cinematography this is called breathing as the edges of the frame seem to breathe when focus is racked back and forth between subjects.

This is generally not something that still photography lenses are designed to compensate for, and the EF 16–35mm f/4L IS USM, as show in the filter tests, is no exception there.

Fortunately give the lack of shallow depth of field and wide angle of this lens, breathing shouldn’t be much of a problem. Moreover, a full focus length pull like show in the tests isn’t something that’s going to be especially common in practice either.

Close Focus Distance/Maximum Magnification

Ultra-wide angle lenses usually can focus close, and the EF 16–35mm f/4L IS USM is not an exception to that. The minimum focusing distance is just over 11 inches (0.28m). Thats pretty much standard for an ultra-wide in this focal range.

Maximum magnification, on the other hand, is not the strong suit of ultra-wide angle zooms, at the 35mm position magnification is 0.23x.

Conclusion

The big question is, “Has Canon managed to make a wide angle lens that doesn’t make discerning users cringe?”

Fortunately the answer appears to be a resounding yes.

Lens Data

Optical Specifications
Focal Length 16 mm — 35 mm
Angle of View (Full Frame) Diagonal: 108°10′ – 63°
Vertical: 74°10′ – 38°
Horizontal: 98° – 54°
   
Min Focusing Distance 0.28 m / 0.92 ft.
Max Magnification 0.23x @ 35 mm
   
Max Aperture f/4
Min Aperture f/22
   
Max Aperture by Focal Length f/4 at all focal lengths
   
T-Stop by Focal Length t/4.5 @ 16 mm
t/4.6 @ 20 mm
t/4.5 @ 24 mm
t/4.5 @ 28 mm
t/4.6 @ 35 mm
   
Aperture Design 9 blade, rounded
Optical Formula 16 elements in 12 groups
Elements/Coatings 2 UD, 3 Aspherical
   
Stabilized Yes
Stabilizer Performance 4 stops
Stabilizer Modes On / Off
   
Breathes when Focusing  
Parfocal No
   
Focus
Focus Type Rear
AF Type Ring USM
Full Time Manual Yes
Focus Ring Rotation 80° from MFD stop to ∞ mark
91° from MFD stop to ∞ stop
E-TTL 2 Distance Info Provided Yes
Distance Scale/Type Yes, Window
Focus Limiter? / Positions No
   
Zoom
Type Ring, Internal Zoom
Zoom Lock Yes, at any focal length
   
Build
Length 4.44″ / 112.8 mm
Diameter 3.25″ / 82.6 mm
Weight 1.36 lbs. / 615 g
   
Material Metal barrel, metal mount
Finish Black
   
Filter Threads 77mm
Weather Sealed Yes with filter
   
Misc
Lens Hood / Included EW-82
Tripod Ring Include / Removable No
Extender Compatible No
Case / Included LP1219 / Yes
   
2016 Camera AF Data (5D Mark 4, 1D X mark 2)
AF Group: C
AF Points: All 61 active
21 central cross active, 20 edge cross types are active
Group Diagram(s)
   
2012 Camera AF Data (5D Mark 3, 1D X)
AF Group: C
AF Points: All 61 active
21 central cross active, 20 side cross active
Group Diagram(s)
   

 


  1. CPN Product Page, EF 16–35mm f/4L IS USM manual, pp 1,9.  ↩

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