Photography advice needed

[David88vert]

Use a lower aperture. Just remember when you get lower than 1/30 on the shutter speed you'll start getting camera shake.

Try playing around in aperture or shutter priority mode for a while (Ax or Tx on Canon)

To expand on what blank said:
Use a larger (lower number aperture) when you do not have to have a deep depth of field - that will be plenty of shots. Example: If you go from f/8 down to f/4, you gain 2 stops of light, and that will allow you to drop the ISO 2 stops lower.
Use a slower shutter speed when possible - for still objects, use the old saying that you should take your lens mm and use it as the shutter speed. Example: with a 50mm lens, go with 1/50 to start. You should be able to handhold using this as a guideline. If you have VR or IS on your lens, you can gain at least one stop slower of shutter speed, and probably 2 stops slower.
VR and IS only works on still objects though - not on moving ones. On moving objects, I like to keep at least 1/125 shutter speed.


I am with blank - use aperture and shutter more than manual. The camera is a computer, and can do some of the calculation for you. Use that to your advantage.

On ISO - I like to shoot as low of an ISO as I can. The reason why is dynamic range and noise. The higher that you take the ISO, the less dynamic range that you have, and the more noise that you get. Some cameras do better than others though. My D600 is quite happy at ISO 3200, and still has good dynamic range and low noise, while the old D70 suffered at 1600.
Your XSI looks to have just under 11 stops of dynamic range, and it falls off quickly over ISO800. That means that you have to look at the dynamic range of each shot closely and determine how much shadow and highlight information that you are willing to use when you turn up the ISO. Here is a chart that shows it for your camera:
http://www.dxomark.com/index.php/Cam...Canon/EOS-450D
Click on Measurements, and then on Dynamic Range.