Buying a new lens is a responsible business. The quality of your photos, their clarity and depth depends on the right choice. In order not to be disappointed in the purchased lens, it is necessary to check it for defects.
Instructions
Step 1
Lens testing begins with an external inspection. Look carefully for any scratches or scuffs on the plastic parts of the lens. Pay attention to possible cracks and dents - these may indicate that the lens has been dropped. This is also evidenced by the "clatter" sound of the lenses when the lens is lightly shaken. With such damage, the lens is not very useful for use: even if it works now, in the future you are likely to encounter problems with focusing, zooming and other troubles. Inspect the screws carefully. Scratches on them and nearby indicate that the lens was disassembled, respectively, repaired.
Step 2
Examine the lenses carefully. A small amount of dust and light small (up to 2mm) scratches on the front lens are allowed - they will not significantly affect the pictures. However, dust and scratches on the rear lens should alert you: the closer the defects are to the sensor, the more they affect the image quality.
Step 3
If your lens is a zoom lens, rotate the zoom ring. It should move smoothly, not jam or creak. At the same time, the ring should not dangle, otherwise it will be difficult to maintain focus. Extend the lens to its maximum length and wiggle slightly by pushing down on it. The backlash should be minimal.
Step 4
Now try the lens in action. Enjoy sharp focus by capturing multiple shots in both auto (AF) and manual focus (MF) modes. Try to take pictures at both long and short focus, as well as photograph objects of different distances. Set different aperture values to test how much the lens will "lather" at its maximum open aperture. If there is a stabilizer in the lens, take several shots at medium shutter speeds with and without it, then judge the difference.
Step 5
Captured footage is best viewed on a large monitor. If this is not possible, use the camera screen, zooming in as close as possible. Evaluate the sharpness of objects in focus, including checking the quality of the image around the edges of the frame - it is usually slightly worse there. And pay attention to the bokeh (the area of blur that is out of focus).
