The aperture ring is in the lens of your camera.
Locate the small screws holding the next element - the aperture ring - into the lens. Unscrew them and gently detach the aperture ring from the lens.6. Lift the front guide ring off the aperture ring, using a magnetized screwdriver.
Instructions
1. Turn on your camera. Set the f-stop on the camera lens to its lowest setting, such as "f/8." Look for the lowest number to set the camera on its lowest f-stop rating. Turn the camera toward you and look into the lens. Depress the shutter button and watch for the aperture blades to come across the center of the lens face. Watch the blade movement carefully for sticking as this is one of the most common problems plaguing aperture rings on older cameras.
2. Focus your camera lens to its shortest distance. Grasp the focusing barrel on the outside of the manual or digital SLR lens and twist the front cover of the lens counterclockwise to remove the front cover from the lens.
3. Unscrew the front retaining ring by gripping it between your thumb and index finger and turning the ring counterclockwise. Carefully set the retaining ring aside on a microfiber cloth.
4. Turn the next ring counterclockwise and remove it from the lens. Set it on the cloth.
5.The aperture ring on a camera lens controls the amount of light allowed into the lens at the moment the shutter is depressed. Aperture is expressed as "f-stop" numbers such as "f/22" or "f/1.8." Larger f-stop numbers allow more light into the lens. Consequently, a broken aperture ring can render pictures either overexposed or underexposed. While a truly broken aperture ring on a digital SLR or manual camera requires a professional camera repair person, you can try a few simple techniques first and possibly save yourself the time and cost of a professional repair.
Gently set it on a microfiber cloth.
7. Loosen the screw at the back of the ring that holds the aperture ring together. Do not remove it entirely; loosen it just enough to unscrew the aperture ring housing. Turn the housing counterclockwise until it separates from the ring, revealing the aperture blades beneath. Remove the aperture blade unit from the camera.
8. Dip the aperture blade unit into a small dish filled with rubbing alcohol. Take the lens to a camera repair shop if you are still experiencing problems with the aperture ring.
Carefully remove the aperture blade unit from the alcohol and set it on a microfiber cloth. Let the unit dry for 12 hours or overnight. Wipe the aperture ring and housing with a clean microfiber cloth to remove any dust from the pieces. Wipe the blades with the cloth to remove any dust as well.
10. Reassemble the blades into the housing unit. Screw the blade housing back onto the aperture ring by turning it clockwise. Thread the screw tightly to hold the blades and ring together. Screw the remaining pieces of the aperture ring back into the lens and reattach the lens to your camera.
11. Depress the shutter button again with the f-stop still set at "f/8." Verify that the aperture blades do not stick when the shutter button is depressed. The alcohol acts as a solvent to loosen and remove grease or oil from the blades, which may be causing them to stick when you press down your shutter button. Let the blades sit in the alcohol for five minutes.9.
