Help with soft photo's from 24-105

[crazyman229]

I have the 24-105mm F4 L but i am havening some problems with shooting clear pics at a distance here is a pic and a 100% croped part af the pic you can see that it is not 100% sharp

449727

1/500 shutter and f8 at 93mm ISO 400 no flash

[crazyman229]

help

[lannes]

help

what camera body are you using it on. ?
were you using a tripod by chance ?
are you using Canon Digital Photo Professional to process the images ?
Is any part of the image sharp ?

[crazyman229]

i use a xsi no tripod and photo shop cs3 no part of the pic is sharp

[WilsonC]

If I were you I would do a test. Maybe grab a DVD box, or some other object with text to take some test shots. Make sure the subject has enough light on it. Manually throw the lens out of focus and then let it auto-focus and take a shot. Then test it using manual focus.

Are you using all the focus points, or selecting just one? Are you in AI Servo, or One Shot focusing?

[crazyman229]

i am using only the center af point and shouting in one focusing
450194
1/512 F8 50mm iso 400
see this is sharp so i know the lens can do sharp it is just when i am further back.

What i am saying is how far away from the subject can i be and still be able to count the eye brows.

[sebr]

Something is definitely wrong with the first shot. Sharpness should not be affected by shooting distance, although counting eyebrows will depend on both shooting distance and focal length.

I'd try to do simple test to eliminate variables. Try shooting at different distances with the same focal length (magnification will be different), from the same distance at different focal length, etc.
Make sure you shoot center point, one shot mode.

You should also post in the lens forum to get more answers. Your thread is in the lens archives, where people put photos obtained with different lenses.

[Ouessant]

Careful not to come closer to the subject than MFD.