dr4gon.net

In this article, I unbox and review the lens. Writeup and sample images after the break. This is a much more expanded version of my preview earlier this week.

Note: I said I would have it done by the weekend and it's mostly done. I want to do some sample pictures (100% crops) but the weather this weekend sucked so those will have to wait till later this week when we get some sun.

Introduction

Like the 7D, this thing is huge (670g). It complements the 7D nicely. The total weight is now about 3.3 lbs with the lens mounted. Coming from an entry level DSLR and crop lens, it's quite a step up. As a pro level L lens, the build quality is very good. Now I know what everyone raves about be it a Canon L, Sony G/Zeiss, or Nikon high end lens. This lens features image stabilization (IS) up to 3 stops, ring USM for quick AF, and one Super-UD element and three aspherical lenses to minimize distortion and those pesky chromatic aberrations (CAs).

Specifications

History

This lens was first introduced in 2005 as a complement to the widely acclaimed 17-40mm EF F/4L USM and 70-200mm F/4L IS USM. These three lenses make an ideal F/4 zoom lineup that will fit the budget of most advanced amateurs and some professionals wanting cheaper, smaller, lighter lenses that carry the same build and quality of the 16-35mm F/2.8L, 24-70mm F/2.8L (no IS), and the 70-200mm F/2.8. At 1 stop darker, many of these lenses are actually sharper than their F/2.8 counterparts at equivalent apertures (70-200mm F/4 comes to mind). So if you aren't needing F/2.8, the F/4 lineup make for a perfect combination.

Unlike it's hefty brother (the 24-70mm F/2.8L), this lens has a less obtrusive hood and weights about 2/3 in weight. This lens is a little different in that when you zoom to a longer focal length, the barrel moves forward whereas in the 24-70mm, the barrel extends as you zoom out (become wider).

Reasoning Behind the Lens

Many people would regard this and the 24-70mm F/2.8 lenses as full frame (FF) only lenses, but it does have a place on crop bodies even with a 1.6x crop factor (or 1.5x for Sony and Nikon). 24mm on APS-C is considered wide, but it's definitely not "ultra wide" like 17mm or 18mm which are borderline. The FOV between say 17mm and 24mm is large, but I wouldn't consider it significant and it seems like it would fit my needs just fine. Time will tell. With a 4.4x zoom length though, it's extremely versatile for a walk around. So far, I am really enjoying it.

My previous lens was the venerable Tamron 17-50mm F/2.8 Di-II (crop lens). I found that the lens was a bit too short for a walk around. I always felt the urge to have a slightly longer focal length. The wide angle only had a limted use for some candid shots at a party (where even 24mm would be wide enough) or landscapes.

Product Shots

Build Quality

The build quality of this lens is outstanding. Everything about it screams quality. Everything feels solid. Like several other L lenses, this lens is also weather-sealed with o-rings and gaskets to keep out  dust and moisture (including some rain). The zoom and focus rings are smooth and firm. There is no zoom creep, yet the ring is not too tight or too loose. It is a perfect balance and you can feel what you are paying for.

The lens extends while zooming, but does not rotate while focusing as previously stated. This makes it a lot easier to use a polarizing filter (CPL) when outdoors. I wish it had internal zoom, but it would probably be a lot longer if it did. Another odd thing, perhaps a Canon thing, is that to zoom the lens, you must turn it counter-clockwise. All of my previous lenses from Sony were exactly the opposite, clockwise to zoom in. It was odd at first, but I'm quite adjusted to this wayward zooming mechanism.

The lens sticks out about 4 inches from the EF lens mount on the 7D body. Without the hood and the pop up flash enabled, at 24mm, there is no shadow. With the hood (adding about another 2 inches) at the longest end, there is a pretty substantial shadow casted. At 35mm, it's still there, but lesser. By 50mm, it's gone. These results were with the camera level and the subject at 3 and 6 feet away. Just be careful to remove the hood if you need to use the pop up flash in an emergency situation at the wide settings.

Auto Focus (AF) Speed

As a professional L-grade lens just over $1000, you wouldn't expect anything less than ring-type USM focusing. With the Ultrasonic motor, the lens zips from close to infinity very quickly, quietly, and most importantly, accurately. On the 7D, the lens has no trouble focusing in low light and very dimly lit conditions. Even a single small LED light will enable it to lock focus with relative ease. Stepping up to these ultrasonic motors from screw-drive is a huge difference! It's so much quieter, faster, and seemingly smoother.

Image Quality (Still missing sample images for sharpness, flare, vignetting, distortion, and macro.)

Sharpness

This lens is a very sharp one. Even wide open at F/4 it is extremely sharp, particularly in the center. As you hit 70mm+, center corner sharpness at F/4, falls behind, but is still decent. Across its entire focal length, F/5.6 to F/8 will give you maximum sharpness. Even at F/11 where diffraction begins to set in, it is still extremely sharp.

Bokeh

The bokeh on thie lens is pretty smooth in almost all conditions (except the tough ones with certain tree and other plant foliage). See the samples below for yourself. The 8 circular aperture blades do a good job at creating a pleasant out of focus background. In comparison to the 24-70mm F/2.8, it's probably a trade off. While F/2.8 will probably give even more pleasant results, 105mm will have the same effect and the differences are probably so minor, I'm willing to bet you couldn't tell them apart. This is probably a better lens for portraits as a narrower DOF is usually more desirable.

The samples are all shot at F/4. The bokeh improves slightly as the lens is stopped down.

Vignetting:

Distortion: At the widest setting @ 24mm on an APS-C camera (7D), there is a slightly noticeable mild to moderate barrel distortion, not at all uncommon for a lens of this type. After about 40mm, there's a minor pincushion, but overall, very well controlled.

Flare/Coma:

Color:

Macro: This lens does a surprisingly good job for some macro work, when using it as a general walkaround lens. It can get pretty to your subject (about 10 inches from the end of the barrel at 105mm and even 24mm). It has a maximum magnification of 0.25X and is able to resolve some fine detail.

Image Stabilization:

Value

The EF 24-105mm F/4L IS USM is an excellent choice for anyone looking for a standard zoom lens that's fast, affordable, lightweight, and has stabilization (IS). Other options for full frame especially include the 24-70mm F/2.8L or for crop sensors the EF-S 17-55mm F/2.8 IS. They're all priced similarly and all offer different advantages. See which one best fits your needs and I'm sure you won't regret your decision because you can't go wrong with any of these three lenses.

On a budget, consider third party alternatives such as the new 17-50mm F2.8 VC, the update to the 17-50mm Di-II with vibration compensation (optical IS). It's probably one of Tamron's most used lenses and they've finally integrated stabilization for the Nikon and Canon mounts. The only thing this lacks is AF speed (and noise) as Tamron still uses micro motors in all of their lenses for Nikon and Canon (screw-drive for Sony). In Sigma land, you could consider the 24-70mm EX DG HSM. It has a fast quiet auto focus with HSM and delivers decently sharp results by F/4 across its range.

Conclusion

TBD pending final images.

Sample Images

Coming later this week.