HomeDonateNewSearchGalleryReviewsHow-ToBooksLinksWorkshops AboutContact Canon 17-85mm © thegioinghiduong.com   Canon EFs 17-85mm IS (APS-C coverage only, 67mm filters, 16.5 oz./469 g, 1.1"/0.35 m close focus, about $299). Enlarge. I got mine at Adorama; I"d also get it at Amazon or at B&H. This ad-free website"s biggest source of tư vấn is when you use those or any of these liên kết to approved sources when you get anything, regardless of the country in which you live. Canon does not seal its boxes, so never buy at retail or any other source not on my personally approved danh sách since you"ll have no way of knowing if you"re missing accessories, getting a defective, dropped, damaged, returned, store test or used lens. (My approved sources ship from remote automated warehouses where no salespeople or lookie-loos can ever get their greasy fingers on your new lens.) Buy only from the approved sources I use myself for the best prices, service, return policies and selection. Thanks for helping me help you! Ken. Bạn đang đọc: Canon ef June 2015 More Canon review Canon Lenses All Reviews SALE: Canon 17-85mm IS: $299. INTRODUCTION back lớn top. Skip to Specs Performance Recommendations  I use Adorama, Amazon, eBay, Ritz, B&H, Calumet, J&R & ScanCafe. I can"t vouch for ads below.
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This is Canon"s best basic midrange digital zoom.
It"s got great IS for sharp shots without a tripod.
It"s super sharp, has great Image Stabilization, focuses almost instantly and is easy khổng lồ use and carry. It"s a great lens!
As an EF-S series lens it only works on the recent small sensor (1.6x or APS-C) cameras, lượt thích the Rebels (Rebel, XT and XTi <300D, 350D and 400D>), 20D & 30D. It won"t even fit on the older D30, D60 & 10D.
SPECIFICATIONS back to lớn intro và index.
Name
Canon calls this the Canon Zoom Lens EF-S 17-85mm f/4-5.6 IS USM.
EF: Electronic Focus. All modern Canon lenses bởi this.
-S: Only works on newer, small (1.6x factor) DSLRs, which are the 40D, 30D, 20D, 20Da (astronomical), Digital Rebel XTi, Digital Rebel XT & the original Canon Digital Rebel.
IS: Image Stabilization. See Why IS Matters.
USM: Ultra-Sonic Motor: It focuses silently.
Focal Length
17-85mm. It gives a field-of-view similar lớn the view a 28 - 135mm lens gives on a 35mm camera.
Optics
17 elements in 12 groups.
Diaphragm
Six blades, reasonably rounded for the first two widest stops. Stops down to f/22 - 32.
Close Focus
1.1" (0.35m).
Filter Size
67mm, plastic thread.
Hood
EW-73B, not included (not needed, either).
Case
LP1116, not included.
Weight
16.545 oz (469.0 g), as measured by me, without filters or caps.
Size
3.078 diameter x 3.606" extension from mount (78.11 x 91.68mm) at 17mm.
4.656" (118.33mm) extension from mount at 85mm, all as measured by me.
Made of
Plastic exterior và switches.
Metal mount. Internals unknown, looks mostly plastic.
Made in
Japan.
Introduced
September 2004.
Price
June 2015: $299 on sale.
2006 ~ 2011: $500 - 600.
PERFORMANCE back lớn intro and index.
Overall Apertures Distortion Focus IS LCA Sharpness Sound Zoom
OVERALL back lớn intro & index.
It"s precisely made of good, solid plastic. It"s made lớn tight tolerances & there is very little mechanical play.
It"s a handy lens for walking around.
It has instantaneous focus, great image stabilization, & gives sharp images.
It feels like the precise, unique product it is.
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Except for the wide angles being crammed together on the zoom ring, making them hard lớn select, this is pretty much a perfect lens.
This 17-85mm never gets in your way. It focuses fast và close at every focal length, is easy to zoom, has great IS, and just works as it ought to. Bravo!
MAXIMUM APERTURE back lớn intro và index.
17mm: f/4
24mm: f/4
35mm: f/5
50mm: f/5.6
85mm: f/5.6
DISTORTION back khổng lồ intro & index.
It has a lot of barrel distortion (bulging out) at the wide end, which goes away in the mid & tele range.
Here are the values I use with Photoshop CS2"s lens distortion filter lớn correct the distortion, shot on a 1.6x sensor camera (30D, 20D, 10D, D60, D30).
These figures are for you to enjoy in your photography. This is all © & registered, so you"ll need permission to use these figures for anything else. Thanks! Ken.
17 mm: Strong barrel distortion. Corrects best with +4.5, but remains wavy.
24 mm: Pincushion distortion. Corrects best with -2.0, but remains a little bit wavy.
35 mm: Pincushion distortion. Corrects well with -3.0.
50 mm: Pincushion distortion. Corrects with -2.2.
70 mm: Pincushion distortion. Corrects with -2.0.
85 mm: Pincushion distortion. Corrects with -1.5.
FOCUS back to intro & index.
AF is silent và almost instantaneous. This is spectacular: it"s faster than my own eyes!
It has instant manual focus override: just grab the focus ring. Manual focus works great at every focal length. It"s very well cammed.
Autofocus tốc độ
Almost instantaneous on a 30D và 20D! It snaps into focus faster than I can measure. It focuses faster than my own eyes.
Autofocus Accuracy
On a 30D, the focus was always dead-on, wide-open at every focal length.
Perfect!
Manual Focus
Easy: just move the ring with the tip of one finger. You don"t need khổng lồ bother with any switches. Want AF again? Just tap the shutter halfway again.
Focus moves in the opposite direction from Nikon. Don"t try to do this if you use both systems.
Macro
17-85mm IS at closest focus at 85mm, full image.
100% crop from above, no extra sharpening. Looks great!
It looks great at close distances. The close focus distance doesn"t vary with focal length.
The less expensive 18-55mm EF-S II gets closer.
IS, IMAGE STABILIZATION back lớn intro and index.
Read Why IS is Important to understand what these ratings mean.
I fired 65 shots, casually (not match-grade) hand held, at each focal length, or about 3 - 5 rounds at each shutter speed and focal length. I used a 30D & looked at the results at 100%, which is a very high magnification.
Holding more carefully I could have gotten better results.
Viewed at lower resolution, like what you"d see in a 4x6" print, you"d get much, much better results.
As you read at Why IS is Important, some of my shots at một nửa second were perfectly sharp, too. These are averages.
TIP: In dim light, fire several shots & pick the sharpest. It"s a random event, so if you fire enough shots, you"ll eventually get a sharp one even ar speeds of 1 second!
17 mm: Always sharp at 1/8, not sharp at 1/4
35 mm: sharp 1/2 of the time at 1/8 và 1/4. Not sharp at 1/2.
80 mm: Always sharp at 1/8, not sharp at 1/4.
LCA (Edge màu sắc Fringes) back to intro and index.
17mm: Moderate. You"ll see it if you look for it. The 18-55mm EF-S II is much better.
24mm: Minor. You have khổng lồ look hard khổng lồ see it.
35mm: None.
50mm: None.
70mm: None.
85mm: Almost none. You really have lớn look for it, & then it"s just on the verge of your imagination.
SHARPNESS back khổng lồ intro và index.
So long as you stop down a stop or two, your technique will be your biggest barrier lớn sharp photos. I have a page on How lớn Get Sharp Photos.
Here are my observations on an 8 MP 20D. Letters correspond lớn center - edge. Possible ratings are E - VG - G - F - phường These are subjective. Don"t fret over differences between adjacent grades.
Diffraction is usually the sharpness-limiting factor for all lenses, especially digital SLRs, at about f/11 and above. See also How Sharpness Varies with Aperture.
