Can you change exposure settings in manual mode on a canon 450D camera if so how?
The Manual Mode means that you are selecting the exposure – the ISO, the shutter speed and the aperture (F stop). In the other modes, like aperture priority (Av), shutter priority (Tv) you select ISO plus one other of the three and the camera calculates the remaining componet. For example, if you select ISO 100, set the aperture at F5.6, the camera will determine the proper shutter speed. When you select M on the dial, you need to set all three. ISO is easy, go ahead and set that at 100 if you are shooting in good light. Now, when you look through the viewfinder, you will see a scale on the bottom that shows exposure. It shows the proper exposure (line right in the middle), and -2 and +2. Using the thumbwheel, you will be changing the shutter speed. Try moving the wheel and see if you can get the little indicator in the middle of the scale, If you can’t you may need to change the aperture first. To do that, you need to press and hold the AV button (see your manual, page 72, if you don’