the first lens refracts the incoming rays of the object such that the image created by the first lens becomes the object for the second lens. hence, the object distance for the second lens, , simply equals . careful, if the image due to the first lens lies to the right (on the outgoing light side) of the double-lens system, the image distance would be considered positive according to the lens conventions discussed in the previous labs. since this image of the first becomes the object of the second lens, and this object lies on the outgoing light side, would the object distance for the second lens then be positive or negative?