Please Help re Canon 24-70 f/2.8L II - not sharp

[Maria]

Hello!

I got my 24-70 f/28L II last fall.  I picked it because i wanted a lens that was good in low light and sharp.  I primarily take pictures of my daughter who doesn't tend to stand still much but am able to get some posing out of her.

I'm really struggling with this lens in that i'm finding very few images are tack sharp - not what i expected. i've come to learn (been told) that many are due to the low light and me not necessarily using the proper ISO so adding noise unnessessarily. 

But even now, in summer in really good light i'm still not gettting great results.  I always focus on one eye and out of maybe 10 shots 2 are sharp.

I'm trying to figure out why my ratio of sharp images is soo low. should it not be higher?  Maybe i'm getting too close, or not using the right settings - really questioning myself.   Maybe it's front or back focusing, maybe maybe maybe...

The other day i took some shots, here are the settings i used for most of the shots:

Canon EOS 6D
Exposure:0.006 sec (1/160)
Aperture:f/2.8
Focal Length:65 mm
ISO Speed:800
Exposure Bias:0 EV

Really good indirect light (in my garage). I was about 5 feet away from her... and out of 10 shots where she was standing still only 2 are sharp and even those i'd argue are a tiny bit off....

here is a link to one of the good ones (but still not great ones).. focus was on her right eye (left one as you look at the image):

https://www.flickr.com/photos/mariaangelo/14414080208/in/photostream/

[hsbn]

A few things you can do to test first:
- Do you focus and recompose? The 6D doesn't have a lot of focus point, so focus - recompose will throw of your focus thus cause the photo to be unsharp.
-Do you have a tripod? Can you set it up and do some test shot with mirror lock up to see if your camera/lens combination is front or back focus?
-Are you shooting RAW or JPG? what software do you use to process your image if it is RAW. Some software will render image slightly soft and you'll have to do some pre-sharpening.
-Are you using any filter?

[cicopo]

at f2.8 the DOF (depth of field) will be rather shallow from that distance. Are you confusing that with a lack of sharpness?

[Skirball]

Sharpness, or the lack thereof can be caused by many things, so it's hard to just point to one thing for a picture like this.

It's hard to tell just how sharp it is (or is not) at such small resolution.  It doesn't look like you're focused on the eye.  Eyebrow perhaps.  You can see that her bangs and hands, which are in front of her face, are in focus more than other parts of the picture.  A photo taken that close, at f/2.8, is going to have a fairly shallow depth of field.  ISO 800 on a 6D should still provide sharp images.  How are you focusing?  (i.e. focus and recompose or are you using your AF points?)

1/160 is fast enough for still subjects, but not for moving.  I suspect you're probably frequently in the grey area in-between.  You and/or the subject might not move enough to give a blury photo, but it can be enough to reduce 'tack sharp".  It can also create inconsistent results.  Flash is a popular tool not only because it provides more light so you can use lower ISO and faster shutter speeds, but the flash itself is very fast and thus helps freeze the subject, providing sharper photos.

You shouldn't need to do AFMA for a 2.8 lens.  But it wouldn't hurt to try it and see.  I recommend Focal.

 All that said, a 6D and a 24-70 II should be able to produce some impressively clean images.  I would keep working at it.  Perhaps even some controlled tests to rule out faulty equipment.

[RobertTheFat]

---

@Skirball wrote:

Sharpness, or the lack thereof can be caused by many things, so it's hard to just point to one thing for a picture like this.

It's hard to tell just how sharp it is (or is not) at such small resolution.  It doesn't look like you're focused on the eye.  Eyebrow perhaps.  You can see that her bangs and hands, which are in front of her face, are in focus more than other parts of the picture.  A photo taken that close, at f/2.8, is going to have a fairly shallow depth of field.  ISO 800 on a 6D should still provide sharp images.  How are you focusing?  (i.e. focus and recompose or are you using your AF points?)

1/160 is fast enough for still subjects, but not for moving.  I suspect you're probably frequently in the grey area in-between.  You and/or the subject might not move enough to give a blury photo, but it can be enough to reduce 'tack sharp".  It can also create inconsistent results.  Flash is a popular tool not only because it provides more light so you can use lower ISO and faster shutter speeds, but the flash itself is very fast and thus helps freeze the subject, providing sharper photos.

You shouldn't need to do AFMA for a 2.8 lens.  But it wouldn't hurt to try it and see.  I recommend Focal.

 All that said, a 6D and a 24-70 II should be able to produce some impressively clean images.  I would keep working at it.  Perhaps even some controlled tests to rule out faulty equipment.

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I don't mean to wander OT, but something you said caught my eye. What does the speed of the lens have to do with the need for AFMA? As it happens, my Canon 17-55mm f/2.8 requires a +9 AFMA on both of my 7Ds. From my experience, AFMA would have been the first thing I'd have advised the OP to check. (That said, the really good "L" lenses do seem to leave the factory better adjusted than the lesser lenses do. And the 24-70 f/2.8 II had better be a really good lens, at that price!)

[TCampbell]

Auto Focus Micro Adjustment (AFMA) can also be required because of the camera body -- it's not just a lens thing.  E.g. you could put the lens on one camera and find it needs a bit of adjustment, but then move it to another camera body and find it's bang-on target.

As with virtually all lenses... you'll do a bit better if you stop down slightly from wide-open.  However, to REALLY test the lens for contrast and acutance (and all the other things that people generally describe as "sharpness") you'll need a proper test target and a tripod.  You really have to ensure there is no possiblity that the camera could have moved (and also that the target could not have moved) and then you need a target that shows if the lens nailed the focus (vs front or back focus and by how much).

There are simply too many factors that "might" have impacted focus accuracy and those need to be isolated and eliminated before concluding that there's an issue with a lens.

[AllNoAll]

If you're shooting f/2.8 close to subject on a moving person the cause is most likely caused by the autofocus not being focused exactly on you subject. You have a very shallow depth of field; I would shoot at f/4 or f5.6.

[ScottyP]

Both seem to be focusing on something in front of the ideal target, which would be the child's eye and the horse. Are you selecting just one focal point and putting that point over the subject? The one of the horse seems quite a bit off, as if you were catching focus on the wooden fence right in front of you and not the subject horse. It almost seems like maybe all the focus points were active and the camera was picking which ones to use, and it liked the fence.

[jagilliam]

Hey Maria,

I'm having issues with mine as well.  I own a 70-200 f/2.8 II and the photos are always nice and sharp.  With the 24-70, it's a crap shoot at best.  One of my co-workers took this shot and several others.  They look nice and shart until you zoom into them. 

- Jamie

[bratkinson]

Using to the numbers provided by the OP, the online Depth of Field calculator http://www.dofmaster.com/dofjs.html calculates a depth of field of about 3"!  In looking at the photograph of the little girl, I'd say that's just about right.  Her nose and eyes are in focus, but her hair from about her ear on back are out of focus.  Exactly as expected for a 3" DOF.

Part of understanding the exposure triangle is knowing what the positive and negative consequences of each setting produces.  Wide open apertures, f2.8 and wider, will produce a suprisingly 'thin' DOF, especially at telephoto focal lengths (> 50mm) and the subject is close to the camera.  Sometimes the thin DOF is wanted, sometimes it's not.