17-40L bad copy?

[K-amps]

Just got a new 17-40L from a local shop (along with the 70-200mmL IS). The focus on the 17-40L seems off... it is worse than what I remember on my 18-55 kit lens. I know not scientific enough... but having tested the 70-200mm on my 1D2, it seems sharp enough as I would expect any L lens to be, and I am not comparing the 17-40L to the 70-200, but it really does not seem sharp enough.

Does anyone know of QA issues with the 17-40L?

[rol11]

Just got a new 17-40L from a local shop (along with the 70-200mmL IS). The focus on the 17-40L seems off... it is worse than what I remember on my 18-55 kit lens. I know not scientific enough... but having tested the 70-200mm on my 1D2, it seems sharp enough as I would expect any L lens to be, and I am not comparing the 17-40L to the 70-200, but it really does not seem sharp enough.

Does anyone know of QA issues with the 17-40L?

I have the same problem....sharpness of my new 17-40 is far worse than my Canon 50mm f1,4 and Sigma 70-200. I also expected better results...

[steven63]

I have this lens.  It's fine.  I first calibrated it to both my cameras (5dmii and 7d) using lensalign and the microadjusts.  But I'm sure you made similar calibrations so perhaps you have a bad copy?

[Flake]

You should certainly read the article linked from this site 'this lens is soft & other myths!'

The 17 - 40mm isn't the sharpest lens, and if you follow Canon sites you'll know about having to stop it down to get the best results. Corner sharpness on FF is not good and border performance also leaves much to be desired, this improves with stopping down, but the centre should be fine.

Wide angle lenses offer greater depth of field than longer focal lengths, so the fact you're complaining about a lens like this not focussing properly makes me wonder about how you're using it.  Wide open fairly close focussed?

[K-amps]

I have this lens.  It's fine.  I first calibrated it to both my cameras (5dmii and 7d) using lensalign and the microadjusts.  But I'm sure you made similar calibrations so perhaps you have a bad copy?

I do not have lens align, and my 1d2 does not support microadjust that I know of. Currently I am just eye balling it and it just seems worng. I have it ona 1.3crop body so the corners are not even an issue for now. I tried it stopped at f8 still nothing impressive. I put on a 70-200mm and it is razor sharp... I bought these yesterday new form a store locally. I think I can return/ exchange them... should i get a Tamron 17-50 f2.8 instead or replace it with another copy of the 17-40L?

Here a pic I took today. No PP done. Camera was on a tripod. Stopped at f4 though.

[neuroanatomist]

I first calibrated it to both my cameras (5dmii and 7d) using lensalign and the microadjusts.  But I'm sure you made similar calibrations so perhaps you have a bad copy?

The OP has a 1D MkII (and had a 350D before that) - no AFMA.

Just got a new 17-40L from a local shop (along with the 70-200mmL IS). The focus on the 17-40L seems off... it is worse than what I remember on my 18-55 kit lens. I know not scientific enough... but having tested the 70-200mm on my 1D2, it seems sharp enough as I would expect any L lens to be, and I am not comparing the 17-40L to the 70-200, but it really does not seem sharp enough.

In the center with the aperture wide open, sharpness is similar between the 17-40mm and the 18-55mm kit lens, but away from the center the cheap kit lens is noticeably sharper.  In the f/5.6-f/8 range, they are similar across the APS-C frame.  At 17mm on FF, the 17-40mm is soft in the corners even stopped down to f/8.  With your APS-H sensor, the corners should be soft, but the center should be decently sharp.  Looking just at the center of the image, sharpness of the 17-40mm is pretty similar to that of the 70-200mm f/4L IS. 

Read the article Flake mentioned - here's the link.  Another article (also by Roger Cicala) is also worth a read - how to test a lens.  It's important to distinguish between AF errors and softness - manually focusing is usually the way to do that.

[I have it ona 1.3crop body so the corners are not even an issue for now. should i get a Tamron 17-50 f2.8 instead or replace it with another copy of the 17-40L?

The Tamron 17-50mm projects an APS-C image circle - it will vignette heavily on APS-H.

[K-amps]

Thanks John:  Here is another pic I took at f8. It looks a bit better than F4 but still.. smells like a kit lens or even worse.

The 70-200mm F4L is much better than this guy in sharpness across the board. It is not even close.

[neuroanatomist]

Pick a scene with some fine detail in the center (printed text, for example).  Shoot a few shots with each lens, but much closer with to the subject at 17mm (so the target is approximately the same size in all images), manually focusing each time.  Pick the sharpest shot from each lens and compare them.  If the 17-40mm still seems soft, return it and try another copy.

[Flake]

The image is too small to pass comment on, plus lots of jpeg artifacts you could have taken this with a pinhole!

As I said in my original post you've done exactly what I suspected - close focus wide open!  This lens does not perform well wide open, particularly at the wide end.  Take it outside, plant it on a tripod at f/11 and at 20mm with a remote release & mirror lock up, then you'll be able to tell how sharp it is.  Try it at infinity focus then try closer subjects, use some hyperfocal distance and inspect the images at 100% If you still have a problem post an example full size.

[K-amps]

Pick a scene with some fine detail in the center (printed text, for example).  Shoot a few shots with each lens, but much closer with to the subject at 17mm (so the target is approximately the same size in all images), manually focusing each time.  Pick the sharpest shot from each lens and compare them.  If the 17-40mm still seems soft, return it and try another copy.

I am more confused now... with every shot I take with the 17mm, it seems to get sharper... I don't know why. I did as you said and did some test shots. 17mm was stopped down to f8 and the 70-200mm was left wide open at f4 ... so the 17mm did have a bit of an advantage... tell me what you think of the 2 test shots. First is the 17mm @ f8 @17mm

[K-amps]

Here is the 70mm to 200mm @F4 @81 mm both cropped

[K-amps]

The image is too small to pass comment on, plus lots of jpeg artifacts you could have taken this with a pinhole!

As I said in my original post you've done exactly what I suspected - close focus wide open!  This lens does not perform well wide open, particularly at the wide end.  Take it outside, plant it on a tripod at f/11 and at 20mm with a remote release & mirror lock up, then you'll be able to tell how sharp it is.  Try it at infinity focus then try closer subjects, use some hyperfocal distance and inspect the images at 100% If you still have a problem post an example full size.

Posted 2 more images... seems weird...

Does the 17mm get better with usage?

[akiskev]

Maybe you are learning to use this lens more efficiently!

[neuroanatomist]

Posted 2 more images... seems weird...

Does the 17mm get better with usage?

Looks fine to me.  Are all these shots with AF?  If so, it might just be your choice of what to focus on (some image features are problematic for AF points with particular geometries, but focus targets are usually designed to activate any type of AF point.

[K-amps]

Looks fine to me.  Are all these shots with AF?  If so, it might just be your choice of what to focus on (some image features are problematic for AF points with particular geometries, but focus targets are usually designed to activate any type of AF point.

As you asked, they are MF.

Maybe you are learning to use this lens more efficiently!

Some guy said make sure the AF slider is revved back and forth a few times for a new lens... did that... maybe that worked?