|Canon's EF 70-200 mm f/4.0 IS L Lens
July 15, 2007
I mention photography equipment on this site only when I find something exceptionally good, bad, unusual, or unexpected. The words “unexpectedly good” might be used to describe the Canon EF 70-200 F4.0 IS L lens I recently purchased. I already owned a Canon EF 70-200 F2.8 L (non-IS) lens when I acquired the EF 70-200 F4.0 IS L lens. I made the purchase because I wanted something smaller and lighter in my backpack, and thought that the newer optical design might let me accomplish that goal without loss of image quality. Since the the 70-200 F4.0 IS L is about 1.5 pounds lighter and nearly an inch shorter, it fit my needs in that regard. The new lens also turned out to be an unexpected and significant upgrade in terms of optical quality. What follows is a general discussion of my purchasing research, user experience, and comparison of these lenses. If you are looking for 100% crops and test charts, you will have to look elsewhere.
Lack of Fanfare
Canon’s 70-200mm F4.0 IS L lens has received relatively little fanfare. This seems odd for a lens that has eclipsed the sharpness of Canon's highly regarded 70-200 F2.8 zooms. I suspect this lens has gotten so little attention because it is smaller and less expensive than its more physically impressive F2.8 siblings. A number of online photography forums make it apparent that many confuse the size of their lenses with the size of something else, but that’s fodder for a different story. In short, it seems the lenses some refer to as Canon’s “flagship zooms” have been sunk by a dinghy, and few have noticed.
My own sharpness comparison testing of the 70-200 F4.0 IS and 70-200 F2.8 non-IS lens models only confirmed what Canon’s MTF charts predicted. I used both real world photos and shots of newspaper classified ads taped to a wall. One sheet was placed at the center and another was placed near the corner of the frame. While this is not quantifiable scientific testing, it was well enough controlled that I am confident that the comparisons are accurate. This testing showed the F4.0 IS lens to have substantially greater contrast and sharpness than my F2.8 lens at the apertures I tested. In my tests at F4.0, the F4.0 IS lens was visibly sharper across the entire image, including in the center. By F8 I could not tell any difference in the center sharpness, but the F4.0 IS lens was still visibly sharper at any point further than half way to the frame edge from the center, in the long dimension of the frame. In other words, in terms of a 24x36 mm frame, everything more than 9mm from the center was visibly sharper with the 70-200 F4.0 IS lens. The difference in edge contrast and sharpness is so substantial that in A/B comparisons I could tell which lens was used for any given shot without referring to my notes. The sharpness difference is somewhat less pronounced at smaller apertures, but it is still quite apparent even at F11 and F16.
That’s not all there is to say about the outstanding sharpness and contrast of the Canon 70-200 F4.0 IS L lens. I also compared it at 70mm to my 24-70 F2.8 L lens, and at 90mm to my 90mm F2.8 Tilt/Shift lens (with no tilt or shift applied). The results show the EF 70-200 F4.0 IS L zoom lens to have somewhat better sharpness and contrast than the EF 24-70 F2.8 L lens, and nearly identical sharpness and contrast when compared to the 90mm F2.8 TS-E lens, which is remarkably sharp.
These last results were not completely expected, so I wanted to see if they could be confirmed elsewhere. This lead me to a wonderful Canon lens comparison tool at www.the-digital-picture.com. This site enables you to directly compare 100% crops of an ISO 12233 resolution chart for any two lenses you pick. After picking the lenses, just move your cursor over the crops to switch between lenses. The crops are taken from three areas, near center, near the corner of a 1.6X sensor, and near the corner of a full frame sensor. Comparisons are available for nearly any Canon lens, as well as a few that are made by other manufacturers. This comparison tool confirms all of my test results, and it also shows the 70-200 F4.0 IS lens to be in the same general contrast and sharpness ballpark with the best prime lenses in the 70mm - 200mm focal length range. Take a look for yourself.
My own comparison of the distortion produced by the 70-200 F2.8 L and the 70-200 F4.0 IS L lenses showed that they have identical barrel distortion at 70mm. At 200mm, pincushion distortion of the F4.0 IS model is very slightly worse than that of the F2.8 non-IS model. For practical purposes both lenses exhibit essentially the same amount of distortion.
Light Fall-off or Vignetting
I should mention here that the 70-200 F4 lenses do not really require the tripod ring for shooting from a tripod. These lenses are about half a pound lighter than Canon’s 24-70mm F2.8 zoom, which has no tripod mounting ring available, and which presents no problem simply hanging off the front of most cameras. Hanging either lens off the front of a 1Ds Mark II body mounted on a good tripod works just fine. In fact, when using the tripod ring to mount the 70-200mm F4.0 IS lens to a Kirk BH-1 head, most cameras will be off balance, being much heavier on the camera side. On smaller heads with shorter clamps that allow positioning the camera closer to the post connecting the ball to the clamp, this may not be as severe. I still use the tripod ring in spite of this for the ease it affords in switching between vertical and horizontal camera positioning, and I have encountered no significant problems in doing so.
I have seen a number of complaints in photography forums about the hood Canon provides with the F4.0 lens. One called it "an embarrassment".
Many said it should be of
the "petal" design, like the hood provided with the F2.8 models. I can't imagine being embarrassed by a lens hood and I don't really care whether "petals" or bow ties are in fashion. It should be noted that a
traditional lens hood design can provide the same, more, or less lens flare protection than a "petal" design. It all depends on how the lens and hood are designed to operate together. Regardless, the provided lens hood seems quite effective at preventing flare, which is what matters most
to me. It is also quite sturdy. Its traditional design better allows the lens to be set hood down on any convenient surface
without a lens cap, with less fear of toppling. I do not make a habit of doing this, but have done so occasionally when I need to switch lenses in a big hurry and have no time to put the other one away until after the shooting is done. My only
minor complaint about the hood is that it is heavily flocked inside. This makes it much less reflective and thus better at preventing lens flare,
but the flocking also tends to pick up all manner of dirt. The petal type hood on the F2.8 models has a smooth matt finish inside, which is more easily cleaned and does not pick up dirt. But overall, the lens hood is just fine unless you're trying to make
fashion statement. In the end, Canon's lens designers probably know more than do most about making a hood that works well with a given lens design.
Fit, Finish, and Feel
The fit and finish of my copy of the 70-200 F4.0 IS lens is perfect in every way, but the overall “feel” of this lens is not nearly as nice as the 70-200 F2.8 non-IS lens. Much of this may be due to the extensive use of plastics in the new lens. These give it a less substantial feel, but also make it much lighter and easier to carry. This use of plastics may in fact make the new lens more durable, but in terms of how it feels in the hand, it’s something like holding a Timex watch in one hand and a Rolex watch in the other. The Timex is probably more durable, but it sure doesn’t feel that way. New water and dust protective seals on the F4 lens add friction to the movement of the zoom and focus rings, making the movement less fluid, but at the same time the controls do not stick or move in a “jerky” manner.
Odd Filter Size
A negative aspect of the smaller size of the F4.0 model is its 67mm filter diameter. This fairly odd size will often require the additional purchase of at least a polarizing filter. The best of these will set you back another $130 or so.
Many have complained that the price difference between the IS and non-IS versions of the F4.0 lenses
is too extreme and cannot be justified. It should be emphasized here that the 70-200 F4.0 IS lens is not simply the 70-200 F4.0 non-IS lens with added image stabilization. As mentioned previously, the IS model uses a newer optical design that includes
two UD glass elements and one fluorite element, which account for its substantially increased sharpness, contrast, and price. The new and very effective image stabilization is only part of the cost equation here, and that fact is very often overlooked.
Cost is also likely one of the reasons that Canon does not include a tripod mounting ring with the lens. If they had, the price of the 70-200 F4.0 IS L lens would surpass that of the
70-200 F2.8 L (non-IS) lens. This just wouldn't work in Canon's current price lineup.
P.S. - Sometimes determining which lens is “best” depends more upon how the lens will be used than it does upon lens performance criteria such as contrast and sharpness. For those who must often shoot with apertures in the F2.8 range, there is simply no substitute for one of the F2.8 models. Some argue that image stabilization negates the need for large apertures, but that argument is not entirely true. Like a tripod, image stabilization helps only with camera movement, not subject movement. This means stabilization is not a substitute for a fast lens when moving subjects are photographed in low light situations. Shooting at large apertures is also a common technique used to isolate a subject against an out of focus background, as in portraiture. In this case too, there is no substitute for large apertures.
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This article is Copyright 2005
by Dean M. Chriss, dmcPhoto.com