Canon 15-85mm IS
Canon EF 15-85mm f/3.5-5.6 IS USM (72mm filters, 1.15 feet/0.35m close-focus, 20.2 oz./571g, about $750.) enlarge. This free website's biggest source of support is when you use these links, especially these directly to it at Adorama or at Amazon, when you get anything, regardless of the country in which you live. Thanks! Ken.
It covers the same range as a 24-135mm lens would cover on a full-frame camera, it has Image Stabilization (IS) for tripod-less shooting in any light, you may grab the focus ring at any time for instant manual-focus override, and it focuses super-close, eliminating the need for a separate macro lens. If you can't shoot it with this lens, it can't be shot.
Except for the glass and lens mount, it's mostly made of plastic and it handles and performs very well.
It will not even attach to 35mm, full-frame or 1.3x cameras.
Canon 15-85/3.5-5.6 IS USM. enlarge.
Canon calls this the CANON EF-S 15-85mm f/3.5-5.6 IS USM.
EF means "electronic focus," meaning that there is an autofocus motor in the lens itself. All Canon lenses since 1987 have been EF.
-S means "small" sensor; it only works on 1.6x Canon cameras.
IS is Image Stabilization, which makes tripod obsolete most of the time.
USM means Ultra-Sonic Motor. This means autofocus is almost silent, and that you can grab the big focus ring for instant manual focus override at any time.
17 elements in 12 groups.
1 UD glass and 3 aspherical elements.
Internal focus; nothing moves externally as focused.
Pumper zoom: front half of the lens pumps in and out; longest at longer focal lengths.
Used on a 1.6x Canon camera, it will see angles-of-view similar to what a 24-135mm lens would see on a 35mm or full-frame camera.
Angle of View (on 1.6x Canon cameras)
84.5º ~ 18.5º diagonal.
53.5º ~ 10.5 º vertical.
74.2º ~ 15.5º horizontal.
Close Focus top
1.15 feet (0.35m), specified, from the image plane.
Maximum Reproduction Ratio top
Image Stabilization top
Rated for four stops (16 times) reduction in camera-shake induced image blur.
Use the Canon EF12 II to get close-ups to almost one-half life-size at the image sensor.
The Canon EF25 II is not compatible.
Use the Canon 500D to get close-ups to almost 3s/10 life-size at the image sensor.
Canon 15-85/3.5-5.6 IS USM at 24mm at f/4 (EF diaphragm not visible). enlarge.
Stops down to f/22-38 (only f/36 in third stops).
Hard Infinity Focus Stop? top
You have to let the AF system focus for you at infinity.
Focus Scale top
The ring turns from infinity to the closest focus distance in about 91.º
Depth-of-Field Scale top
Infra-Red Focus Indices top
Filter Thread top
Does not rotate, but moves in and out with zooming.
Canon specifies 3.2" (81.6mm) diameter by 3.4 " (87.5mm) long.
It gets longer as zoomed longer.
20.155 oz. (571.4g), measured.
Canon specifies 20.3 oz. (575g).
$37 plastic bayonet EW-78E, not included.
$25 LP1116 pouch, not included.
Standard 72mm ET-72U front, included.
Standard EOS cap rear.
01 September 2009.
Made in Taiwan.
Canon carefully hides this by molding it in black-on-black into the rear shield, which is invisible with the lens capped or mounted.
Price, USA top
2011 October: $750.
Box, Canon 15-85/3.5-5.6.
The Canon 15-85mm f/3.5-5.6 IS is extremely handy; there isn't anything it can't do. If 85mm on 1.6x cameras isn't close enough, walk closer.
Autofocus is fast and silent.
No problems here, as usual for Canon.
Just grab the focus ring at any time for instant manual-focus override.
Only move the AF-MF switch to MF if you want to disable the camera from auto focusing.
AF Accuracy and Consistency
I saw no autofocus error.
Manual focus is easy; just grab the ring at any time.
It takes only 91 º to go from end-to-end of the focus scale.
Bokeh, the quality of out-of-focus areas as opposed to the degree of defocus, is good.
Backgrounds never distract.
If you want to throw the background out of focus, more important than f/stop is to use the 85mm end of the zoom range and step closer.
Focus breathing (the image changing size as focused) is mostly of interest to cinematographers who don't want the image changing size ("breathing") as the lens is focused among different subjects.
The image from the Canon 15-85mm f/3.5-5.6 always gets smaller as focused more closely, which is backwards from most traditional fixed lenses.
The color balance of this 15-85mm f/3.5-5.6 IS seems to match my other Canon EF lenses.
The Canon 15-85mm f/3.5-5.6 USM has the usual distortion we expect from wide-range general purpose zooms.
It's got moderately strong high-order barrel distortion at 15mm, it's neutral but wavy at 17mm, and has minor pincushion distortion in the rest of the range, except at 24mm, where the pincushion distortion is strong.
If distortion matters, shoot around 17mm or at 85mm.
For critical use, use these values in Photoshop's Lens Distortion tool to remove it:
© 2011 KenRockwell.com. All rights reserved.
* Some waviness remains after correction.
** Lots of waviness remains after correction.
Canon 15-85/3.5-5.6 IS USM. enlarge.
This is an easy to use lens. My biggest whine is that it's bigger and heavier than smaller zooms, and more of a pain to carry around all day around my neck than the nice little 18-55mm lenses that do much of the same thing.
Zoom and focus are plastic, and feel that way. They require a moderately firm touch to move, but they don't creep, either.
The zoom range is reasonably well-cammed, although the wide end is a bit more congested than the tele end. The zoom ring doesn't turn with equal resistance throughout its range; it requires more force around the 24mm range.
The AF-MF slider on the side is right where it needs to be under my thumb.
Falloff isn't visible.
I've greatly exaggerated this by shooting a flat gray target and presenting it against a gray background.
Filters are easy. I can't get vignetting even with a thick polarizer.
There's no need for expensive "thin" filters.
There are lateral color fringes at the wide end.
At 15mm, you'll see probably some cyan-red fringes.
At 24mm, there are only some very minor cyan-red fringes.
There are no fringes around 35-50mm.
At 70mm, there are only some very minor magenta-green fringes.
At 85mm, there again are some magenta-green fringes.
© 2011 KenRockwell.com
Rear, Canon 15-85 f/3.5-5.6. enlarge.
The Canon 15-85mm f/3.5-5.6 IS is mostly plastic, except for the mount and the glass itself.
Painted on barrel.
Feel like plastic.
Moisture seal at mount
Laser-engraved into bottom of lens barrel near mount.
Noises When Shaken
Moderately loud rattling and clunking.
The 15-85mm is sharp enough. It's not as sharp as a 70-200/2.8L IS II, but no other zoom is, either.
Specifically, it's pretty sharp at all settings and doesn't vary much with aperture or zoom setting.
Particularly remarkable is that there is no setting at which it gets soft. Most moderately zooms have some focal-length range or part of the image that gets soft at large apertures, while the Canon 15-85mm has no soft spots,especially at the 85mm end, where it's still sharp corner-to-corner even wide open.
It's never that extraordinarily sharp, but more important is that it never gets particularly soft at any setting.
Here are Canon's claimed MTF curves:
Canon's MTF Curves.
I see no spherochromatism
Spherochromatism, misnamed "color bokeh" by laymen, is when out-of-focus highlights take on color fringes. The Canon 15-85/3.5-5.6's out-of-focus highlights have no color fringes.
Spherochromatism is a completely different aberration from lateral color fringes.
Sunstar, Canon 15-85mm IS at f/10 at 42mm (complete image).
With its 7-bladed diaphragm, this Canon 15-85mm f/3.5-5.6 IS makes marvelous 14-pointed sunstars on brilliant points of light. The blades are somewhat curved and therefore the sunstars have softer spikes.
This is much better than most Canon lenses, even much more expensive lenses like the 70-200/2.8L IS II, which have 8-blades and only make boring 8-pointed sunstars.
AF - MF Switch
Leave this in AF. Just grab the focus ring at any time for instant manual-focus override.
Only set it to MF if you want it to be locked into manual focus.
Leave this on. It eliminates camera shake for sharper pictures. It replaces a tripod.
The stabilizer works even when using a monopod.
The only time to turn it off is if you're on a very sturdy tripod.
The Canon 15-85mm f/3.5-5.6 IS is a great do-everything lens for Canon's 1.6x ("APS-C") cameras. I prefer it over the 18-135mm because this 15-85mm is built tougher, has instant manual-focus override without needing to move a switch, covers a more useful focal length range and makes superior 14-pointed sunstars.
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