A process for layer manufacturing a three-dimensional work piece comprising the steps of: (a) forming a molten pool deposit on a substrate with an electron beam at a first predetermined location; (b) feeding a metal wire in a solid state to the first predetermined location; (c) depositing the metal wire onto the substrate at the molten pool deposit under a first processing condition; (d) monitoring the molten pool deposit for a preselected condition using an image generating device substantially contemporaneously with the depositing step, the image generating device having: i. a cooled housing that encloses a detector selected from a digital camera, a charged coupled device, a complementary metal oxide semiconductor, or a combination thereof adapted for generating images substantially in real time at a rate of at least 25 frames per second and ii. a vapor protection device that is decoupled from the cooled camera housing; (e) comparing information about the preselected condition of the monitored molten pool deposit with a predetermined desired value for the preselected condition of the monitored molten pool deposit; (f) solidifying the molten pool deposit; (g) automatically altering the first processing condition to a different processing condition based upon information obtained from the comparing step (e); and (h) repeating steps (a) through (g) at one or more second locations for building up layer by layer a three-dimensional work piece; wherein the monitoring step (d) includes monitoring a condition associated with the molten pool deposit from a location substantially overhead of the molten pool deposit, and wherein the vapor protection device is aligned so that an axis of the light beam received by the vapor protection device forms an angle from about 2 degrees to about 10 degrees with an axis of the electron beam. (a) forming a molten pool deposit on a substrate with an electron beam at a first predetermined location; (b) feeding a metal wire in a solid state to the first predetermined location; (c) depositing the metal wire onto the substrate at the molten pool deposit under a first processing condition; (d) monitoring the molten pool deposit for a preselected condition using an image generating device substantially contemporaneously with the depositing step, the image generating device having: i. a cooled housing that encloses a detector selected from a digital camera, a charged coupled device, a complementary metal oxide semiconductor, or a combination thereof adapted for generating images substantially in real time at a rate of at least 25 frames per second and ii. a vapor protection device that is decoupled from the cooled camera housing; i. a cooled housing that encloses a detector selected from a digital camera, a charged coupled device, a complementary metal oxide semiconductor, or a combination thereof adapted for generating images substantially in real time at a rate of at least 25 frames per second and ii. a vapor protection device that is decoupled from the cooled camera housing; (e) comparing information about the preselected condition of the monitored molten pool deposit with a predetermined desired value for the preselected condition of the monitored molten pool deposit; (f) solidifying the molten pool deposit; (g) automatically altering the first processing condition to a different processing condition based upon information obtained from the comparing step (e); and (h) repeating steps (a) through (g) at one or more second locations for building up layer by layer a three-dimensional work piece;