When in the house, you can have things as definite as you wish; out-doors you will find a continual play of varying color and light. The shadows do not fall where you expect them to. The values are less marked. The stillness of the pose is interfered with by the constant movement of nature. The color is influenced by the diffused color of the atmosphere and the reflected color of the grass, the trees, and the sky. The light does not fall _on_ the face so much as it falls _around_ it. The modelling is less, the planes are not precise. The expression is as much due to the influence of what is around it as to the face itself.
All this means that you must study and paint the figure from a new point of view. You do not make so much of what the model is as how the model looks in these surroundings. You must not look for so much decision, and you must study values closely. Look more for the modelling of the mass than for the modelling of surface. Look more for the vibration of light and air on the flesh and drapery colors than for these colors in themselves. Look for color of contours in the model. Study the subtleties of values of contours, and make your figure relieve by the contrast of value in mass rather than by the modelling within the outline. See how the figure "tells" as a whole against what is behind it first, and keep all within that first relation.
[Illustration: =Buckwheat Harvest.= _Millet._]
It is possible to look for and to find many of the qualities which distinguish the figure in the studio light; sometimes you may want to do so. The telling of a story, the literary side of the picture, if you want that side, sometimes needs help that way. But in this you lose larger characteristics, and the picture as a whole will not have the spirit of open air in it.
What has been said of the painting of landscape applies to the painting of figures in landscapes. Pose your figure out-of-doors if you would represent it out-of-doors. Then paint it as if it were any other out-door object. If the figure is more important to the composition than anything else in the landscape, as it often will be, then study that mainly, and treat the rest as background, but as background which has an influence which must be constantly recognized.