Your typical auto-focus lens should be a smooth-working machine.
Pro and amateur photographers alike can admire the smooth feeling of a well-oiled camera. But when an auto-focusing lens feels like sand and won't focus properly, then something is clearly awry. That something may be the focus helix, an assembly common to many lenses, which allows the lens to slide back and forth and adjust the focus. The hard part is taking apart the lens to get at the helix. Once you're there, re-greasing is a quick task.
Instructions
1. Dip your rag in acetone and use it to wipe all the grease off the focus helix. Be sure to get into the grooves of the helix. Remove all the old grease from the assembly, because this can cause the lens to work slowly.
2. Apply a light coating of grease to the helix. Apply enough so that the function improves significantly, but not too much, because this will cause the assembly to get clogged up and stall.
3. When reassembling the lens, wipe off any excess grease from the focus helix that comes into contact with other parts of the lens. This will allow your lens to work well and keep the grease where it needs to be.
4. Once the lens is reassembled, work the focus to its limit back and forth several times with your hand in order to seat the grease in the assembly.
Tags: focus helix, back forth, because this, grease from, lens work
