So, you are getting consistantly soft pictures? Here's your problem. The most likely reason that you are getting soft images is because of two factors: 1)your camera and/or your lenses are most definitely out of adjustment 2)you are shooting with too small a Depth of Field.
Something you must know about the 10D. Canon considers the 10D a "consumer" level camera, that is, it is not officially a professional piece of equipment. As such, the factory spec for focus adjustment is that the focus point only has to be configured to be "anywhere" within the Depth of Field (DOF). That means that if the aperture, subject distance from the camera, and the focal length for a given shot provide a DOF of, let's say, 4 inches, then the focus point of your 10D can be in the front of the 4-inch DOF or it can be in the middle or it can be at the back end of the DOF. Huge, huge variance my friend! Have you tested your camera? Do you know if your 10D is front focusing or back focusing? Is your camera out of adjustment? You know, your camera may be out of adjustment and its focus point may not even be within the DOF. Very, very, very possible, and, in my opinion, quite probable with the 10D.
Something else you absolutely must be aware of is shooting with settings that provide very small DOFs. When you set up a shot and use various settings for f-stop, focal length, and distance from the subject, do you know what DOF you are creating? Did you know that if you shoot at 70mm focal length with F2.8 from seven feet away from the subject that your DOF is only 3.7 inches? So, if you are doing a shoulder shot or head shot of someone with these settings and your camera is focusing at the back end of the DOF and you sway forward one inch and the subject sways forward toward you one inch just at the moment you take the shot, you are hopelessly out of focus!
The problem is probably not limited to the camera only. Your lenses (L or otherwise) are probably not perfectly adjusted either. So, add that probability to the probability of your camera being out of adjustment or at least back focusing or front focusing "within" the DOF and you will get tons and tons of soft images.
I speak from experience. I was getting many, many soft images with my two 10D cameras and four lenses. I tested my equipment and made a giant discovery. Both cameras were not adjusted properly as one was one was front focusing and the other was back focusing severely. The lenses were performing differently as well. I sent all my equipment ( both cams and all lenses) in to Canon in Irvine, CA and within four days got them back. I tested them all and the equipment was performing much more consistantly. Now, both cams were within spec and performed very similarly. That is, both were just slightly front focusing within the DOF by just about the same amount. That was a great improvement! Something I could work with. Also, the lenses were now performing very consistantly. Huge improvement.
Next, I started studying DOF at different camera settings and made a huge discovery. Without realizing it, I had been shooting many of my shots with very small DOFs. Not good! Now, being aware of the DOF of different settings, now being aware of the fact that my cameras slightly front focus within the DOF, I now shoot with larger and more consistant DOF settings appropriate to the subject that I am shooting. RESULT - virtually all, that's right, virtually all my shots are crystal clear and sharp. After I became "aware" and had my equipment recalibrated and started shooting with "smarter" settings, my soft images went away. Ever since then (April 2004), my wedding shoots consistantly result in 97% tack sharp images! Huge, collosal, monumental difference!
Ever wonder why some people will say great things about a certain lens and others will say that they only get mediocre results concerning the very same lens? Ever wonder why some people will say that they get tack sharp photos sometimes but at other times they get soft pictures and that they don't understand why they are getting mixed and inconsistant results? Ever wonder why some people say that the 10D is fantastic, that the 17-40, or the 24-70 or the 28-135 or the 70-200 are fantastic lenses and they get tack sharp images beyond belief, but others emphatically DON'T say that? Well, it's because Cameras and Lenses are not adjusted the same right out of the box. In fact, I would say that the majority of cameras or lenses that you buy are probably not perfectly adjusted when you get them.
Based on my experience and having read thousands of posts on these forums, it is my policy and advice to assume that equipment is delivered to you OUT of ADJUSTMENT. I now test all my new equipment BEFORE using it professionally. That way I know if a particular lens is front or back focusing and by how much. Once I know that, I shoot accordingly. If it is way out of whack, I get it adjusted by Canon...and then I test it when I get it back, just to make sure. That is just HALF the problem fix.
The other half of the problem fix is to shoot KNOWING the DOF of your shot settings! Know what getting two feet closer to your subject does to the DOF. Know what a change of 10mm of focal length does to your DOF. Know what a single F-Stop does to your depth of field. Don't shoot with miniscule DOFs if you want sharp images. The way I look at it is, if I want a sharp portrait shot, I will choose settings tha give me at least a 10 inch DOF (a person's face is at least that thick) and add more DOF to compensate for my equipments' front or back focusing tendency.
The 10D is no Mk ll as far as I know, but you can get absolutely magnificent images with a 10D, magnificence guaranteed if you know your equipment and DOF settings and shoot accordingly.
