Here i have very best method with which you can boost up DSLR speed. The following method is given from
Nikon D80 Manual therefore, in case you feel any issue in understanding or implementing these steps, directly visit to given manual and take help from there:
Turn your camera on and then turn the Mode dial to align the S with the indicator line.
Select your ISO by pressing the i button on the back of the camera.
Press up or down on the Multi-selector to highlight the ISO option and then press OK.
Press down on the Multi-selector to select the desired ISO setting, then press OK to lock in the change.
Point the camera at your subject and then activate the camera meter by depressing the shutter button halfway.
View the exposure information in the bottom area of the viewfinder or by looking at the rear LCD panel.
While the meter is activated, use your thumb to roll the Command dial left and right to see the changed exposure values. Roll the dial to the right for faster shutter speeds and to the left for slower speeds.