Most of the portraits, then of necessity were profiles formed upon back-grounds, the lighter parts relieved upon black, and the darker parts upon light ground; the back-ground proper being of light colored material with black velvet so disposed upon the light ground, this being placed sufficiently far from the sitter, to produce harmony of effect when viewed in the field of the camera.

Other difficulties presented themselves seriously to the working of the discovery of Daguerre, to portrait taking--one of which was the necessity for a constant and nearly horizontal light, that the shaded portions of the portrait should not be too hard, and yet, at the same time, be sufficiently well developed without the "high light" of the picture becoming overdone, solarized or destroyed.

In almost all the early specimens of the Daguerreotype, extremes of light and shade presented themselves, much to the annoyance of the early operators, and seriously objectionable were such portraits.

To overcome this difficulty, Mr.Wolcott mounted, with suitable joints, upon the top of his camera, a large looking-glass or plane reflector, in such a manner that the light of the sun (as a strong light was absolutely necessary), when falling upon the glass could be directed upon the person in an almost horizontal direction.
Early in February, 1840, Mr.Johnson, Sen., (since deceased) sailed for Europe with a few specimen likenesses taken with the instruments completed as above, with the intention of patenting the invention.

On his arrival a joint arrangement was effected with Mr.Richard Beard, of London, in patenting and working the invention in England.