17-40mm F4 not sharp

Hi all,

 

Somehow I felt my 17-40mm F4L is not as sharp as people claim it to be.

I am not sure if this is a focus problem or not.

 

Can you please take a look at it for me?

 

If this is out of focus, then my question will be how do you focus when the focus points on the 5d are grouped so

close in the center area?!

 

Thanks..

 

 

[Directly posted oversize images removed]

I find my 17-40 to be pretty sharp. I am not sure I see a lot of issues with the image sizes posted. I do see softness at the corners with your models feet. However, what F-Stop are you at and also what focal length do you have the lens set at? This could be shutter speed or movement. The corners on mine are a bit soft at F4 but sharpen up pretty well at F8. I use a 5D. Are you using a camera with a full frame sensor as well? It looks like the center of the image is fairly sharp. I am guessing you were pretty close to the model so this may be a depth of field issue as well.

There is quite a difference in depth from the toes and the model's face and eyes. Looking at the perspective given by the stair case, it looks like it to me. I wouldnt expect the toes or other peripheral items in the image, in such a case.

 

Assuming you were focused on the face, yes the photo is not VERY sharp. Sharp, for a consumer lens, but not L sharp. However, the setting seems a bit dark to me. It reminds me of pictures taken in museums. Are you shooting at a low shutter speed? Camera shake perhaps?

Stanly, what the shot details? ISO, shutter speed, Aperture setting?

They look good but not great. With an expsure of 1/15, even if it's not camera shake, the stairs could be vibrating or the model moving, I think that's what the softness problem is.

Hi all,

 

Thanks for the reply. I don't know how to link the exif to photo.net, however th exif can be seen from flickr if

you click the photo.

Anyways, here's the info.

 

The first photo

Camera: Canon EOS 5D

Exposure: 0.067 sec (1/15)

Aperture: f/4

Focal Length: 28 mm

ISO Speed: 800

Exposure Bias: 0 EV

Flash: Flash fired

 

The 2nd Photo

Camera: Canon EOS 5D

Exposure: 0.067 sec (1/15)

Aperture: f/4

Focal Length: 32 mm

ISO Speed: 800

Exposure Bias: 0 EV

Flash: Flash fired

seems oversized :p

 

Camera: Canon EOS 5D

Exposure: 0.067 sec (1/15)

Aperture: f/4 Focal Length: 28 mm

ISO Speed: 800

Exposure Bias: 0 EV

Flash: Flash fired

<a href=" title="IMG_9403 by superroadstar, on Flickr"><img

src="http://farm3.static.flickr.com/2107/2520723695_cfa6ee57b3.jpg" width="333" height="500" alt="IMG_9403" /></a>

 

Camera: Canon EOS 5D

Exposure: 0.067 sec (1/15)

Aperture: f/4

Focal Length: 32 mm

ISO Speed: 800

Exposure Bias: 0 EV

Flash: Flash fired

<a href=" title="IMG_9415 by superroadstar, on Flickr"><img

src="http://farm3.static.flickr.com/2205/2521524334_e8997b13e5.jpg" width="500" height="333" alt="IMG_9415" /></a>

I don't see any softness problem. But indeed, at 1/15th, you'll be lucky to get real crisp sharpness.

 

Also, did you do any post processing or did you shoot them as JPG?

I remember I shot JPG.

um.. Somehow I still feel the image is not sharp enough comparing to my 70-200mm F4 IS.

ISO 800, 1/15 @ F4? Not sure what you are expecting, but you certainly arn't going to get it with those settings in those conditions.

 

Set up a tripod, shoot at F11, ISO 100 and you will see why people rave about this lens. There is no magic bullet for less than ideal conditions. If that were the case, everyone could be a wedding photographer.

Everyone could be a wedding photographer?

 

Um, no.

 

I'll stick with horses thanks.

Ditto what David said.

<p>To understand the capabilities of this lens more fully (and not to check for a "bad copy") it is worth spending a few minutes

running it through a simple set of tests. The usual: camera on tripod, MLU, remote release, plane of subject parallel to sensor.

Start at say 17mm and f/4. AF the subject and then disable AF. Use aV mode and shoot a series at f/4, f/5.6, f/8, f/11, f/16, f/22.

Zoom to perhaps 24mm and repeat the process. Again at perhaps 25mm. Finally at 40mm.

 

<p>The results will inform your photography in several ways. First, you'll better know the center and corner performance of the

lens at different apertures and focal lengths - understanding where it is strongest and weakest. Second, you'll have eliminated

some of the non-lens variables (like hand holding at very slow shutter speeds) and this will help you nail problems that you may

run into in the future.

 

<p>I do this with each of my lenses - once, when I first get them. Again, this is not "bad copy" paranoia - not at all. The goal is to

quickly come up to speed on the "personality" of each lens so that I can use it more effectively.

 

<p>Also, I posted some links to info/examples I've posted using my 17-40:

 

<p>Center sharpNess at 100%: <a href="http://www.gdanmitchell.com/2006/01/28/canon-17-40mm-f4-l-sharpness/

">http://www.gdanmitchell.com/2006/01/28/canon-17-40mm-f4-l-sharpness/</a>

 

<p>Corner sharpness on FF at different apertures: <a href="http://www.gdanmitchell.com/2008/01/21/corner-sharpness-of-the-

canon- 17-40mm-f4-l-lens-on-full-frame/">http://www.gdanmitchell.com/2008/01/21/corner-sharpness-of-the-canon- 17-40mm-f4-l-

lens-on-full-frame/</a>

 

<p>Dan

@ Peter....

 

didn't say everyone would WANT to be a wedding photographer :)

I like this last recommendation. I usually figure I've got what I've got, and I have to be happy with it, or make a change after a while, once I am familiar with the lens. Usually I get the best I can afford, and don't have any other choice (that would be acceptable to me) anyway, so I just live with what I've got, and make the best of it. Then, eventually, something changes (like my budget or available options).

Stanley;

 

That lens is not notoriously sharp among the L lenses. In fact it's probably the softest. Especially wide open.

And your 70-200 F4 is probably the most sharp. So not a fair comparison.

 

I think you'll find that most of the photogs who rave about it's sharpness are landscape photographers using it stopped down for max DOF. There is fair amount of bad/soft copies of this lens, ( I know I had one ) and yes you should check for that.

 

But I think the main problem is that you shot at 1/15th with focal length about 30mm on both shots. If it was a 40D, I don't recall, then your focal length was really abourt 48 so you'd need to shoot at 1/50th at least. Also F4 on that lens will be softer and wide open minimizes DOF. The lighting was less than ideal. I think more diffused flash power would have helped create some of the "Pop" you were looking for.

 

In the end, I feel this is probably at least 75% technique but suspicious enough that it could be 25% soft lens. So, I'd recommend checking the lens and definately re-shoot.

@ David,

 

Phew! That's good to know.

"That lens is not notoriously sharp among the L lenses. In fact it's probably the softest. Especially wide open. And your 70-200

F4 is probably the most sharp. So not a fair comparison."

 

Yes. And no.

 

Take a look at my samples. The links are about three posts above yours.

 

The 17-40 is not particularly sharp wide open, especially in the corners. But that is pretty much par for the course in Canon (esp.)

UWA zooms. However the center becomes very sharp quite soon as you stop down and the corners become quite good on FF if

you shoot at "landscape apertures" - e.g. f11 and smaller.

 

(The statement about the unfair comparison to the 70-200 is right on. Very different lenses with very different performance

characteristics.0

 

I think the OP would be well served by testing the lens in the way I describe above, mainly to understand what it does well and

where its weaknesses are. If the lens is OK - and it probably is - and the OP wants to shoot wide open a lot at UWA focal

lengths, my might be a good candidate for the 16-35mm f/2.8 is he shoots FF and perhaps the EFS 17-55mm f/2.8 IS if he

shoots crop.

 

(If he is more likely to shoot stopped down (e.g. - architecture, landscape, etc.) and only occasionally shoot wide open it is still

possible to make the 17-40 work fairly well.)

 

Dan

In the first pic, the model's torso looks nice and sharp, so perhaps that is where the camera focused on (centre

focus point used?). Then with f/4 the depth of field is maybe small enough to put her feet and head slightly out

of focus. Her right leg (the one on the left in the pic) is soft - looks like the model moved during the

relatively slow 1/15 sec. shutter speed.

 

I do like the location with the lighted stairs and that light shining upwards onto her legs. I would echo some

of the other posters comments and try shooting on a tripod, at a faster shutter speed(1/200 or 1/250 to sync

flash, or 1/125 without flash), and close the lens down to f/8 or f/11. This of course means either bumping the

ISO or more light. Doing this would also eliminate some of the soft corners inherent in most wide angle zooms.

 

Overall, I like the pics.

Thanks a lot for all your responses. In the thread, I learned not only the lens but also some of the shooting

technique. It was very rewarding especially for a 1-year newbie. cheers~

1/15 sec is too slow, you should be using a faster shutter speed like 1/200 or 1/125, why choose 1/15?

I don't recall anyone mentioning this, but I would also select the centre focus point and only use that. Focus and recompose as desired...