Is my focusing technique wrong?

I used to think that my 300D with 18-55mm couldn't focus worth a damn. I realized what I was doing wrong, and changed my style (using centre focus point only) and most of my problems went away. Then I was thrust into shooting in really low/poor light conditions, and tons of indoors. I quickly learned what to look for in regards to Aperture/Shutterspeeds​/ISO to get back lost shots from camera shake.

Then all the gear was stolen. Now I've got the 20D, and thought for some reason my pictures would end up 10X better, but it just doesn't work that way, does it. Still more learning ahead.

Another Bridal shower to shoot. More low light. No external flash. Now using the 20D and 17-40L. All the pictures turned out yellow/pink, and all seem blurred. Not even as sharp as what I was getting with the 300D and 18-55mm.

I've figured out the yellow/pink problem. Quick lesson in setting White Balance. Quick lesson in learning why you might want to shoot in RAW. Figured out there is no need to jack ISO up to 1600 when using the built in flash, since it defaults to f4@1/60 regardless of ISO level. The 1600 just seems to roughen/soften all edges and make the entire scene a little blurred in an ugly sort of way.

Or is it me and my Centre Focus Point method of obtaining focus? You see, almost all the photo's were of groups of people or couples. Centering the shot would always have the Centre Focus point fall on a background object, so I always would focus on 1 persons face, and then recompose the shot. Is this wrong? How 'out' of focus can a shot become by using this method? Is there a general rule on distances to subject where you do not want to use this method? Or is it just that the 17-40L isn't the hottest lens when in a low light situation?

My problem is sharpness or lack thereof. I've taken camera shake out of the equation since I'm getting 1/60th speeds. That leaves me with ISO, and/or Focusing technique as being the culprit. I just don't know what to think anymore.

try setting the custom function of AF point selection. Then you can use the little joystick on-the-fly to choose any of the 9 AF points

using the center focus point (in "one shot" AF mode), focusing on the subject, then recomposing is a perfectly good way of focusing. this is how it was done before multi-zone AF, and indeed how it was done with a split-prism-screen manual focus camera.

run some tests at home indoors in the evening with the lights dim. experiment with the different ISO values (and corresponding shutter speeds). figure out where your softness is coming from.

a 20D can make a "sharp" shot at ISO1600 -- sharp as in an 8x10 print sharp. pixel-peeping may show otherwise, but it doesn't matter if the prints you intend to make look sharp.

Take a look at page 82 of your 20D manual. The A-Dep mode averages all active focal points, increasing depth of field. It's great for group shots.

The "focus on one person, lock focus, then recompose" method works well if everyone stays completely still between the moment you lock focus and the moment your shutter opens. If you are shooting wide open, with a narrow dof, natural movement of your subjects (+/- a couple of inches) could throw the shot out of focus.

Maybe you have not taken camera shake out of the equation. There is a reason why modern tripods were invented. When I was a beginner, I practiced to hold my camera more steady without a tripod. Then, at the exact instant that my finger went down on the shutter button, I jerked the camera slightly, so I had camera shake anyway.

---Bob Gross---

Okay.. once and for all.. say my hands are about as steady as a heroine addict going through withdrawal. What's the minimum shutter speed I can get away with?

I used to think it was 1/30th. Soon realized it wasn't enough. 1/60th seemed great. After heaving drinking I can almost pull off 1/10th.

one problem i think exists that no one seems to mention, is that going from one body to another of smaller size and weight can lead to unsharp photos.

The handheld rule (without flash) is the reciprocal of the effective focal length. By effective, I mean using the 1.6 factor. However, some people have shaky hands. I tend to shoot with a very long lens, so a tripod became almost mandatory for me.

---Bob Gross---