I agree with Clowns and it may have been the same issue with soons as well.
If you turn on all 9-AF points, the camera tries to be smart and predict what you want to focus on. But the centre focus point is usually the sharpest (or most accurate).
So, 2 things come into play here when selecting centre-focus point:
1. Select the focus point to centre-only
2. Select AF to One-shot
Selecting One-shot AF allows you to recompose the shot after focusing. Alternatively, if you are tracking the subject, then select AI-Servo. Do not try to recompose with AI-Servo because it will AF according to where the centre focus point is being moved to. Similarly, do not try to track a subject using One-Shot because it will not re-focus itself once AF is achieved initially.
So there's your answer after 6 pages:
1. Select centre-focus AF
2. Try shooting in RAW (in RAW, concentrate on getting the trinity correct - Shutter / Aperture / ISO. The rest can be manipulated)
3. Check for lens/body calibration problems
4. Practice handholding techniques
5. Practice shooting under different lighting conditions (at home etc)
6. Read the manual when in doubt
7. Ultimate decision - if the above still doesn't convince you that the 500D + 55-250IS is decent for you, buy a 5dMkII or something else.
If you turn on all 9-AF points, the camera tries to be smart and predict what you want to focus on. But the centre focus point is usually the sharpest (or most accurate).
So, 2 things come into play here when selecting centre-focus point:
1. Select the focus point to centre-only
2. Select AF to One-shot
Selecting One-shot AF allows you to recompose the shot after focusing. Alternatively, if you are tracking the subject, then select AI-Servo. Do not try to recompose with AI-Servo because it will AF according to where the centre focus point is being moved to. Similarly, do not try to track a subject using One-Shot because it will not re-focus itself once AF is achieved initially.
So there's your answer after 6 pages:
1. Select centre-focus AF
2. Try shooting in RAW (in RAW, concentrate on getting the trinity correct - Shutter / Aperture / ISO. The rest can be manipulated)
3. Check for lens/body calibration problems
4. Practice handholding techniques
5. Practice shooting under different lighting conditions (at home etc)
6. Read the manual when in doubt
7. Ultimate decision - if the above still doesn't convince you that the 500D + 55-250IS is decent for you, buy a 5dMkII or something else.