Need help on Canon 17-40 F4L Lens [Archive] - Canon Digital Photography Forums

mso

28th of April 2006 (Fri), 11:20

Choderboy

28th of April 2006 (Fri), 11:28

Looks like you are having bad luck getting a decent copy.
Final pic shows that it's not a front or back focus issue - it just does not focus at all.
Hard to see how you could be at fault - consistent results with the kit lens.....
but all shots with thew 17-40 worse.

Oh well , good luck.

Tsmith

28th of April 2006 (Fri), 11:44

I agree with Dave _ the 17-40L is a stellar lens. It should be sharp even at f/4 if everything is right.

SuzyView

28th of April 2006 (Fri), 11:46

Don't say that. My 17-40L just came today!

mso

28th of April 2006 (Fri), 12:59

Don't say that. My 17-40L just came today!

Could you please post a F4 20 mm picture taken with the lens... It would be very nice to see how yours perform in the corners.

mso

28th of April 2006 (Fri), 13:02

SuzyView

28th of April 2006 (Fri), 13:20

74404

Here's the 17-40L at 4.0 without a flash inside with light from 4 windows. If you want it cropped, I can do that.

karusel

28th of April 2006 (Fri), 13:57

It is sad that the factories don't actually calibrate and TEST their products...

Suzie, it only makes sense if you post a 100% crop as it is impossible to judge sharpness from a downsized image... ;) And also, what focal length was that shot at?

One more thing, I forget where, but I've read on photozone, that someone had ther lens calibrated by some service and got it back superbly sharp.. has anyone done that?

foxbat

28th of April 2006 (Fri), 14:25

Could you please post a F4 20 mm picture taken with the lens... It would be very nice to see how yours perform in the corners.The corners of the 10D sensor are still quite close to the center of the lens. ;)

mso

28th of April 2006 (Fri), 20:14

74404

Here's the 17-40L at 4.0 without a flash inside with light from 4 windows. If you want it cropped, I can do that.

Hey thx for the sample. The samples in my link (above) are blurred in the corners that is when photographing in one plane (no foreground nor background only one plane). If you try to zoom in on the books only so that the books will fill out the entire frame (preferentially at 20 mm like my shots) and F4 (you might need a tripod or support from a table) then I would be better able to see how the sharpness of your 17-40 copy is compared to mine.

The problem with having objects at different distances in the frame is that when one focuses on the middle part with a big apperature then the foreground and background objects will be naturally blurred.

I hope you can follow me :confused: If it's not to much trouble for you I would really appriciate it :)

mso

28th of April 2006 (Fri), 20:18

One more thing, I forget where, but I've read on photozone, that someone had ther lens calibrated by some service and got it back superbly sharp.. has anyone done that?

A certified Canon center has had a look at my lense and my camera. They made some adjustments to the AF on both the camera and the 17-40. It didn't help at all. The images I linked to in the beginning of the post were taken after they had done the adjustment.

SuzyView

28th of April 2006 (Fri), 22:00

It was late in the afternoon and I couldn't get enough light to take the picture without the flash on. I will try in the full sunlight in the morning. It was at 20mm, btw and I kept getting some glare off the VHS tapes. I don't have any books in that room so I will have to think of a way to get close enough to show it. I will set at f4.0, 20mm at close range, about 1.5 feet, Right?

pup

28th of April 2006 (Fri), 22:07

i was talking with someone today who said he heard many people were having problems with the 17-40L specifically, so you arent alone.

Tsmith

28th of April 2006 (Fri), 22:19

i was talking with someone today who said he heard many people were having problems with the 17-40L specifically, so you arent alone.

I haven't had any issues at all with my copy, lucky uh? I've heard of a few members here having to return copies but the same can be said for several other lens too. Seems every other person who gets a Sigma 24-70 f/2.8 has to send it back for calibration.

My 17-40L ranks right up there with the 70-200 f/4L in sharpness and IQ.

Dorman

28th of April 2006 (Fri), 22:48

My copy seems razor sharp to me, even when used wide open.
MSO - yours definitely makes me suspect that something is wrong

shniks

29th of April 2006 (Sat), 06:14

Well, from what you have posted your 17-40 seems a little sharper in the middle, but softer at the edges (when compared to the 18-55). Considering the poor lighting conditions I dont think the 17-40 performed too badly. The only thing concerning is the soft edges, but I think the centre crop looks great. Try the same test in better light and see what you get.

SuzyView

29th of April 2006 (Sat), 21:30

I took my 17-40L out today on my EOS 3 and had 3 shots before the roll finished, ran it to Sam's to process in 45 minutes. The copy I have is superb on the EOS 3. I had used my Tamron 19-35 at a wedding shoot and forgot the film wasn't done. Compared the two on the same roll of film and there's just no comparison. I love ff and the 17-40L is so sharp, I wanted to cry. I will try the lens on my 20D tomorrow, but had the 24-70L on that camera all morning. Didn't want to switch with the pollen count at maximum. But I think I will mainly use my 17-40L outside where the light is not an issue and the focus is dead on for sure.

websurfer

30th of April 2006 (Sun), 01:36

I can only say - I have two sharp Canon lenses. Apparently I have to be grateful. Too bad Canon.
If I were you, I would send it in for repair / calibration.

mso

2nd of May 2006 (Tue), 12:24

Hello Everybody

Thx for your replies.

Another hobby photographer has submitted his test pictures to my site. Please have a look. His pictures aren't to great either :(

web page: http://msomso.homepage.dk

Sam

2nd of May 2006 (Tue), 13:59

Looks like bad copies to me? Mine is fantastic, no issues optically for me. Maybe it's related to build date?

mso

2nd of May 2006 (Tue), 18:59

Looks like bad copies to me? Mine is fantastic, no issues optically for me. Maybe it's related to build date?

Hmm perhaps. Unfortunately i didn't check the production date I have sent the lense back and will try a new one from another store perhaps... But it must be some kind of bad batch or something...

If anyone would like to contribute to my lense test feel free to submit an unedited test shot with exif data. Preferrably at wide angle and large aperature.

My problem now is that I have seen test shots from three copies of the 17-40 and they have all been very soft at the corners at F4 (in comparison to my kit lense) so I'm not sure if I will purchase this lense again. The lense isn't exactly cheap so I really want it to be sharper than the kit lense. Colors and contrast I can fix in Photoshop if it comes to that, but true sharpness is harder to imitate in CS.

AmericanFirst

2nd of May 2006 (Tue), 19:06

What are you doing throwing a decent lens like that on a RebeL???

Buy a body, will ya? Then check...

StealthLude

2nd of May 2006 (Tue), 19:15

you cant test a lens w/o a tripod...

I thought my 70-200 was a "bad copy" till i threw it on a tripod and found out it was just a little shake... Ends up being super sharp

Bosphorousman

2nd of May 2006 (Tue), 21:44

you cant test a lens w/o a tripod...

I thought my 70-200 was a "bad copy" till i threw it on a tripod and found out it was just a little shake... Ends up being super sharp

...EXACTLY! Just what I was going to mention. I've had my 17-40L for about 18 months now and I have not had any trouble focusing. The only blurred pix I get are a result of my hands shaking when the shutter speed is too slow.

I have noticed that most of the time the lens gets the blame, when it is really user error instead. Always use a tripod if you have to test your lenses.

Your test wasn't always consistant with each lens. If you stop the aperture down for one lens, you have to do it for the other. As for the 17-40L being OF at your f/8 example, it looks as though it was hand-held. If not, did you use a tripod and shutter release cable or a shutter remote switch?

The 17-40L is a stellar landscape lens and it shouldn't give the results you got with yours. (It does need good light to perform indoors.)

Just thought I'd share some of my experience with 'lens frustration' and some steps to cure it.

Good luck! Don't give up on it. It IS a GOOD lens!! :)

Lester Wareham

3rd of May 2006 (Wed), 03:17

I'm having big troubles with my last purchase a Canon 17-40 F4L USM. I got a copy 1 month ago which I returned to the store because it was blurred. I have now gotten a new copy but I'm still not satisfied. I have had both my 350D AND the lense adjusted at a Canon service center but still I'm not satisfied. Perhaps my hopes are just up to high??!!

Can anyone take look at the pictures I have posted on my website below and tell me what could be wrong. My test is in Danish but I have used terms as 17-40 F4: and so on to every picture.

Am I just one of the lucky persons who have got a "L"-like kitlense?

http://msomso.homepage.dk/ (http://msomso.homepage.dk/)

Can you be a bit more specific on what the problem is. Is it AF accuracy, or IQ? If IQ compared to what? How are you testing?

My 17-40 is slightly sharper than the kit lens at centre @ 17mm but over the rest of the coverage is much better. At other focal length the 17-40 is better in all respects.

Test on a completly flat surface like newsprint if you don't want to setup a proper test target, use a tripod and mirror lockup and timer mode or a remote release to eliminate all vibration. It is often a good idea to test with more than one AF trial to eleminate the odd rogue bad AF.

mso

3rd of May 2006 (Wed), 05:12

Hello again thx for all your replies.

Well, the test shots on my site are taken with both a Digital Rebel XT and the EOS 20D. The outdoor photos of the vintage bookstore are taken with the 20D.

The shots were taken with the cameras mounted on a tripod.

Two different copies of the 17-40 were used.

Either way a shutter time of at least 1/320 s was used outside so the blur shouldn't be due to shaking hands.

One should notice that the pictures are all quite sharp in the center but very blurred around the center on the 17-40 compared to the 18-55.

Something is wrong... Also at fredmiranda there has been some negative reviews of the 17-40 lately.

I don't try to ruin the 17-40's reputation, I'm still in love with it :D I mean it's build quality, contrasts, the vivid colors it delivers and so on. But sharpness is not as good at wide angels and big aperatures compared to the kit lense. I can't live with the blur I experience at this price point.

Also the test shots are taken at the same focal lengths and aperatures so both the kitlense and the 17-40 should have equal conditions to show their performance.

Btw. I have found links on dpreview were people also complain about this issue.

mso

3rd of May 2006 (Wed), 05:15

I forgot, the timer function was also used to take the shots.

To sum it all up, I'm simply testing the 17-40 the same way as the 18-55 under the same conditions and so on...

Lester Wareham

3rd of May 2006 (Wed), 09:50

I forgot, the timer function was also used to take the shots.

To sum it all up, I'm simply testing the 17-40 the same way as the 18-55 under the same conditions and so on...

I was worried about my new 17-40 having heard similar reports to yours earlier in the year. I think I have quite a good kit lens and have tested the new 17-40 and the kit lens using the ISO method, you should be getting better results than you are. Lens test page is here (http://www.zen20934.zen.co.uk/photography/LensTests/index.htm) if you are interested, 100% crops available on the fstop result pages.