The conditions are not favourable--which makes the demonstration more convincing.

This is a very well-lighted room and Polton is a very poor actor; in spite of which it has been possible for you to sit opposite him for several minutes and look at him, I have no doubt, very attentively, without discovering his identity.

If the room had been lighted only with a candle, and Polton had been equal to the task of supporting his make-up with an appropriate voice and manner, the deception would have been perfect." "I can see that he has a wig on, quite plainly," said I.
"Yes; but you would not in a dimly lighted room.

On the other hand, if Polton were to walk down Fleet Street at mid-day in this condition, the make-up would be conspicuously evident to any moderately observant passer-by.

The secret of making up consists in a careful adjustment to the conditions of light and distance in which the make-up is to be seen.
That in use on the stage would look ridiculous in an ordinary room; that which would serve in an artificially lighted room would look ridiculous out of doors by daylight." "Is any effective make-up possible out of doors in ordinary daylight ?" I asked.
"Oh, yes," replied Thorndyke.