Close ups..pin sharp...Groups... Out of focus !?

[neil_worden]

After using an Eos 20d and 350d at a number of weddings, I have noticed that

group shots are never absolutely pin sharp.

Using both standard lens and 17-85 gives the same frustrating results!

This is driving me crazy, after years of using Hasselblad + film and never

having a problem.

PLEASE someone tell me that they have had similar problems.

I ruled out camera shake by increasing ISO and use Single AF point and one

shot mode.

Is there something I have missed ?

Is there any sneaky sort of hyperfocal trick I could use ?

HELP !

[martin_howard1]

Are you doing any post processing on the images? - most DSLR shots need a fair bit of sharpening, printing often requires more sharpening than is needed for viewing on screen.

<p></p>

<a href=http://www.cambridgeincolour.com/tutorials/sharpness.htm> This site </a>gives a good run down on digital image sharpness issues.

[fgphoto]

I just experienced this for the first time and figured it was me ... maybe not. I have the 30d and took a few rather large group shots at a Wedding this last weekend and they are not as sharp as they should be. What I didn't try was the A-DEP setting. From what I've read, this should help, have you tried A-DEP?

 

Frank

[bugaboo]

Are you sure it's not a visual illusion? For example, It might be that the normal "silky" blur is just more prevalent as the subject gets smaller. I know I see a huge sharpness difference every time I compare my 1Ds (80mm L) to scans from my Hasselblad (70 c*). When reviewing group shots I tend to zoom in further and things can get look pretty blurry.

 

Have you tested your camera with simple patterns? A studio test might be a good idea. It is possible for a camera's AF to mis-read: You may have a camera that needs repair. A friend of mine has a 10D that would always focus about 6" too far. He sent it back and they fixed it.

 

Finally, your lenses could be the culprit. Are any of your lenses known to be sharp? Do you use the same lens for both shots? If not, one of them may be really sharp (the close up one) while the other may not. Quick fix here would be using a higher F stop when shooting groups. There are guides that tell how lenses (regardless of price) preform at different focal lengths and F stops. Google "lens review".

[JosvanEekelen]

What is your aperture? Diffraction can cause some blurriness. Try to avoid the smallest openings.

[mark u]

There are several possibilities:

 

Your expectation of the lens performance is higher than it can manage - consider a better lens.

 

You haven't stopped down sufficiently to gain adequate DoF. You stopped down too much (don't go beyond f/11), leading to diffraction.

 

Your shutter speed is too slow, resulting in motion blur/camera shake.

 

You didn't switch off IS shooting from a tripod.

 

The lens needs mechanical adjustment - compare with another copy, and have yours repaired if need be.

 

AF calibration is wrong either for the lens or the body or both. Do focus tests with the lens on a different body, and a different lens on your body, and send in the offender(s) for calibration.

 

You are enlarging the images beyond what is reasonable to expect in terms of detail. A 6x6 negative has slightly more than 10 times the area of your camera sensor, and with fine grain B&W (or even modern colour) emulsion is probably capable of 3 times the linear resolution or more with a sharp lens. For large group shots, a large film negative has distinct advantages over a 1.6 crop sensor, regardless of the excellence of the DSLR lens.

[lester_wareham]

Put some examples up including 100% crops showing what you mean, also provide the exposure info and if a support was used. Otherwise we are trying to diagnose blind.

[wedding photog]

I recommend using prime lenses whenever possible. Keep everyone on the same plane and use the center focus point to focus on the bride and groom. It is best to shoot with a tripod if you are using long focal length lenses.

 

Do not go below F 5.6 or so if possible.

[neil_worden]

A big thanks to all who have been kind enough to reply. I will try everything suggested and post a message to say which works for me. Please keep them coming !

[jim_d5]

I have this exact same problem and I thought it was just me, too. Keeping everyone in the same plane of focus, as suggested, is almost always impossible with large groups.

 

Recently I shot a group of 40 in three rows and it was quite soft. I was using the Canon 20mm f/2.8, a prime lens with good optics, I used good depth of field and it was tripod mounted with good light. Still a softer than usual photo, now I am thinking how weird that other experience this too.

 

This has been helpful as I am interested in the responses as well. I have to do the shot again (biannually) so maybe I will try all of this.