17-55 IS question/issue.

I have had this lens for a couple of months now and I have found that it seems to be on my 50D much more then any of my other lenses. I'm not sure if I hadn't paid attention or if there is possibly somthing wrong with it but it just doesn't seem to be all that sharp. Is there a way to test the sharpness, or should I send it in to Canon or worse come to worse bring it back to B&H for a replacement?

Any advice would be greatly appreciated.

Thanks,
Nick

Are you shooting Raw or Jpg? as raw doesnt apply any sharpening at all.

I shoot in both, but normally just large jpeg format. Even on the screen it seems as though though the image should be sharper. This is at 100% crop mind you.

can you post samples?

there are alot of issues associated with the 17-55 IS, there is dust, weak IS, etc, but soft images is not one of them.

nordstern1 wrote in post #7866725
can you post samples?

there are alot of issues associated with the 17-55 IS, there is dust, weak IS, etc, but soft images is not one of them.

Sure. I though that maybe my focusing was off so I used the focustestchart.com to see if that was the issue. Turns out that it wasn't but here is a sample.

EXIF: 55mm, F/2.8, ISO 500, 1/320, IS off, mounted on a tripod, large/fine jpeg mode (15mp).

HTTP response: NOT FOUND | MIME changed to 'image/gif'

HTTP response: NOT FOUND | MIME changed to 'image/gif'

Shouldn't worry about it, tbh.

I've had similar issues with the 17-55 I got last December. My focus chart test turned out exactly like yours - the lens seemed to be front focussing slightly somewhere around the 4mm mark. In practice I find that I get very sharp results when focussing on close subjects, but that things get worse with distance and become very soft indeed at infinity. I'm still trying to work out whether it's me (don't think so; I'm pretty duff, but by the law of averages I should have got at least one sharp long-range shot by now), or the lens, or whether the AF on my 40D is inconsistent.

I've posted about this before and I'm on the point of sending the lens back to Canon. However, here is a straight conversion from RAW that I took the other day along with a 100% crop (a very poor shot in very misty weather, but it illustrates the point). The focus point was the church. If y'all tell me this level of softness is normal for this lens at this range when using autofocus, then that's cool and it will set my mind at rest, but given how everyone else raves about its sharpness, I'm not optimistic.

I also noticed someone else complaining about a soft 17-55. I know it's usual to blame the user in such cases and maybe with some justification, but I do wonder whether there's been a duff batch of 17-55s recently, or even whether Canon have dropped the quality.

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amd is the best wrote in post #7866675
I have had this lens for a couple of months now and I have found that it seems to be on my 50D much more then any of my other lenses. I'm not sure if I hadn't paid attention or if there is possibly somthing wrong with it but it just doesn't seem to be all that sharp. Is there a way to test the sharpness, or should I send it in to Canon or worse come to worse bring it back to B&H for a replacement?

Any advice would be greatly appreciated.

Thanks,
Nick

Have you tried the micro adjustment feature on your 50D to see if it helps?

It's hard to tell from your focus test image, but the focus looks to be off by a few mm. Are there any parts of the image that appear to be sharp?

Looks to me from your chart that its front focusing slightly. Truth be told, I'm not overwhelmed by my copy of the 17-55. I did some comparisons with it against the 18-55 kit lens, expecting it to blow away the 18-55, and it did not. Actually it was hard to detect any real difference - I took a a series of the same shots with both lens at different f stops. I think mine may be back focusing slightly, based on the "line up a row of batteries" test. Trouble is there's no adjusting the XSi. I agonized over the choice of the 17-55 as a good walk-around lens and bought it based on numerous reviews and a lot of reading. If I had to do it again I'd probably go with the 17-40L at several hundred bucks cheaper, and compatible with a full frame. Still, I haven't given up on it yet. Just a little disappointed so far.

I too was disappointed when I got my first 17-55mm. I won't lie though, I was fairly new to photography, and 99% of my bad shots were user error. When I learned a bit more, practiced a bit more, and got that shutter speed nice and snappy the images just blew me away. I had some shots later on that I thought should be sharper, but the ones that were sharp made me realize it could not be the len's fault. Not to say that yours is soft due to user error - I'm not sure, as that sample does look a bit soft.

I wouldn't count it off as the lens just yet though, as I was in the same predicament and soon the lens was producing razor sharp results. Stop it down to f/4 or 5.6 and see what the results look like, too. That can make a HUGE difference.

the test chart samples look like the lens is front focusing.

with the sample pics, the foreground looks sharper than the church which was the focus point. front focusing also is my guess...

Jack Dawe wrote in post #7871368
I've had similar issues with the 17-55 I got last December. My focus chart test turned out exactly like yours - the lens seemed to be front focussing slightly somewhere around the 4mm mark. In practice I find that I get very sharp results when focussing on close subjects, but that things get worse with distance and become very soft indeed at infinity. I'm still trying to work out whether it's me (don't think so; I'm pretty duff, but by the law of averages I should have got at least one sharp long-range shot by now), or the lens, or whether the AF on my 40D is inconsistent.

I've posted about this before and I'm on the point of sending the lens back to Canon. However, here is a straight conversion from RAW that I took the other day along with a 100% crop (a very poor shot in very misty weather, but it illustrates the point). The focus point was the church. If y'all tell me this level of softness is normal for this lens at this range when using autofocus, then that's cool and it will set my mind at rest, but given how everyone else raves about its sharpness, I'm not optimistic.

I also noticed someone else complaining about a soft 17-55. I know it's usual to blame the user in such cases and maybe with some justification, but I do wonder whether there's been a duff batch of 17-55s recently, or even whether Canon have dropped the quality.

Mine seems to be the exact same way. Within min focus-3ish feet from the subject at pretty much any focal length, the image seems tack sharp. Anything above maybe 10 feet or so and it seems to go south.

Here is an image I took yesterday with my 17-55. I focused on my cars door handle and this image is just terrably oof.

1/125 sec, f7.1, iso 100, 23mm:

HTTP response: NOT FOUND | MIME changed to 'image/png'

amd is the best wrote in post #7866691
I shoot in both, but normally just large jpeg format. Even on the screen it seems as though though the image should be sharper. This is at 100% crop mind you.

All too many people are fooled into thinking they evaluate sharpness at 100%. A 50D shown at 100% on a 19" 1280x1024 monitor is seeing more than a 60x enlargement and viewing it from about 18-24", which is an insane way to look at any image. Fill the screen with the full image and you are still larger than an 8x10 but you are at least at a sane image magnification.

Are you focusing using only the center AF point or are you letting the camera auto select the AF point?