This lens has obvious deformation around the front ring, which means filters cannot be mounted. There is also blemishes around the body and barrel, but the glass is flawless. Be aware that with this deformed front ring, using filters might be a problem but I've never had need for them. The cap is push on. This lens has been used recently, a shutter is running well on all speeds on 1/8th and faster. Lower than that, they seem slow. For example 1 second seems closer to 2 seconds. Please be aware of this if you are intending to use slow exposures.