[JamieP]

I shot the picture below with my Sigma 24-60 at 35 mm, 1/500 and F 2.8. I wanted to shoot it wide open to really make my son pop from the background. I really liked it on the lcd preview (of course), but was disappointed once I got it on my computer. I think I missed the focus- it looks to me that the hair on the very top of his head is sharp, but his face and eyes are soft. My son was acting very silly when I took this, which means he wasn't holding still. Is 2.8 to shallow to use in a situation like this when the subject is moving around a bit?

I'd appreciate any thoughts on whether the focus is what's lacking in this shot and suggestions about how to prevent missing shots like this in the future.

Thanks in advance!

[Ash]

Well done with the candid - pity about the focus.

Jamie, the fundamentals of using a shallow DoF give you an idea as to how much to stop down with your subjects.

Far away subjects need a shallow DoF to be able to separate the subject from its surroundings.
The closer the subject gets to the camera (and the longer the focal length used), the thinner the DoF becomes at a given aperture.
So for yours, it seems you've used a 50-60mm? FL with the subject close to the camera - f/2.8 would give you a very shallow DoF.

Secondly, if you're sure this boy didn't move in even a hint closer to the camera from the time you locked focus to the time you tripped the shutter, then there is a backfocusing issue with the lens. To be sure of this, use a focus test chart.
Otherwise, learn to recognise when to stop down to get the results you want.

[Eruditass]

Good concise summary, Ash.

Soft potraits are good too, you know! Blur the hair and sharpen/use focus magic on some of the features of the face and see how it looks.

[egordon99]

You need to explicitly select the auto-focus point directly over WHERE you want to focus. Using center-point/focus+recompose won't work at this close a distance/wide an aperture.

Additionally, slight body/camera movement from when focus is aquired until when the shot is taken can also throw the focus off.

If you think f/2.8 is tough, try f/1.4

Cute shot though!

[and]

of course the lens and camera needs to be properly calibrated, if u get wrong focus on a non moving test subject then that problem needs to be fixed first. other than that I normally try to shoot a lot, knowing there will be misses. with the k7 i also have the option of using the live view zoomed in as that will 100% nail the focus, altho if the subject is moving a lot then the shutter lag of that can be too much

[impact]

Focus+recompose works for me. I usually try to focus on the area between the nose and the eye, I dunno why, but it works most of the time.

Subject has to be steady tho. With moving subjects it's always a gamble.

[Marc Sabatella]

Using center-point/focus+recompose won't work at this close a distance/wide an aperture.

Actually, I find it normally works quite well at portrait distances at f/2.8, as long as we're not talking about the most extreme cases (focusing with the centered target all the way in the *front* of the focus zone, then recomposing to put the target in the extreme corner of the frame). For most purposes - putting the centered target somewhere in the *middle* of the focus zone, recomposing to push the target maybe half way to one side of the frame), you'll never notice a discrepancy at f/2.8. At least, not if you nail the rotation without changing distance; the real issue is the possibility that you'd actually move in such a way that you are closer to or further from the target. So you do need to double check in the viewfinder that the focus appears to be correct - meaning focus-recompose it's not a complete substitute for actually verifying things manually.

[Andreas]

Your son was not holding still, that's the culprit IMO. Your depth of field must have been about 2 cm at that distance. Any move will bring him out of focus then.

(I don't think your focus point was lacking, since the eyes are the only area that have contrast here. And although focus recompose could cause an error of up to 2 times your foreground depth of field in this case, I don't think it really mattered compared to the boy's movement, since you did not rotate the picture that much.)

[ll_coffee_lP]

I like the shot a great deal...and think it can be saved by adding some selective bluring on the in focus areas to tone that down. The capture is very good.

A couple of things come to mind for me (assuming you don't have a bf issue with this lens/body combo).

1.) At 35mm to get a framed shot this close (presuming you haven't cropped of course) you would have had to have been very close to the subject. Using f/2.8 at that distance gives you a very narrow dof. Any body sway on your behalf, or the subject's behalf, can throw focus off quickly. Don't be afraid of f/2.8 though - it's very usable even at that range.

2.) Always focus on the eyes. If the eyes aren't sharp the viewer will notice right away. If you are going to recompose - that's fine (I do this all the time) - focus, recompose quickly and snap.

3.) At close distances like this f/4 is also going to blow out the background. It will typically keep the nose and ears in focus too.

Looking at this image I would say either you or subject swayed before the pic was actually taken.

Next test - learning to focus, recompose quickly and snap. Give it a go and see if your results improve.

Good luck!

c[_]

[Fixcinater]

Another method of "focusing" is getting close with the focus ring or AF, and then moving yourself forward and back to get it exactly where you want the plane of focus to be.

Remember that it's a plane, not just a certain spot on his head/face, so you can tilt the camera and get some neat effects, or eliminate those OOF effects, at will.

[Lowell Goudge]

I think your shot is interesting for another reason, not related to subject or to nailing focus.

I have a tamron 28-75 F2.8 XR Di

A year or so ago, my wife took some shots that were soft and out of focus just like your's, and I wrote it off to her not waiting for the AF on my camera but shooting right away. She would not have seen a sharp image i the viewfinder because it is adjusted for my eyesight, and her's is quite different. Any way, a year later, I took some wide open shots, and found it impossible to get truely crisp images, but when I put the camera on program mode, the images came out very sharp.

The difference was program mode stopped the lens down.

I decided to do some tests and found that while most of the time I shoot with the tamron stopped down, in daylight, I found that wide open performance was a little soft, just like your lens.

It would be interesting to do some trials, and comparisons but I suspect many of the fast zoom lenses are a little soft wide open.

[Class A]

My son was acting very silly when I took this, which means he wasn't holding still. Is 2.8 to shallow to use in a situation like this when the subject is moving around a bit?

Did your son move forward while you took the shot?
That would explain why the focus is behind the eyes, approximately where the ears are.

The lens shows good sharpness in the in-focus area and you just missed to put his eyes in that area. If he (or you) did not move forward and you obtained a focus lock on his eyes, your lens might back focus. In that case, try to make an AF adjustment.

[JamieP]

Thanks to you all for your thoughts and suggestions.

A couple of quick updates- I did test the lens and don't think this was caused by a back focus issue or general softness wide open. In reflecting on taking the shot after reading your replies, here is what I think happened:
- I focused on his eye using center spot
- Recomposed
- Waited briefly until I had just the right expression of his face and then shot

I think as I waited (although very briefly) he moved and caused the focus to be off. The next time I shoot in these conditions, I think I'll shoot at f/4 to improve my chances of hitting the focus. I think it would be hard to avoid waiting briefly and still get the exact moment that I want.

[RBellavance]

I think as I waited (although very briefly) he moved and caused the focus to be off. The next time I shoot in these conditions, I think I'll shoot at f/4 to improve my chances of hitting the focus. I think it would be hard to avoid waiting briefly and still get the exact moment that I want.

Stopping down a bit is a good idea.

What you may want to do also is step back a little bit (i.e. frame less tightly), switch to AF.C and keep an AF point on his eye while holding the shutter at half-press. When you see the expression you want, click ! Then you can crop to get the final framing.

That's what I do with my children. There's just not enough time to recompose, in my experience.

PS.: I used to stay in AF.S and keep re-half-pressing the shutter with the K10D, but with the K-7 the AF is too fast and the SR doesn't have time to engage before I take the shot. Using AF.C and holding half-press works around that.

[aleonx3]

Looks like the 1/500 shutter speed is fast enough to freeze any slow movement on the subject; it appears to me that there is a slight BF issue with the lens. Also, I would use AF.S in this case as you would want to camera to lock the focus once you nailed it. I would also use AF selective point to avoid any movement of the camera; just my 2-cents.