( 10) 



and so do the shoulders of the female figure to the right, owing to 

 which especially the left shoulder shows a false relief. Consequently 

 the critical exposure is reached after the greatest transparency of the 

 image has been obtained. 



Between these beginnings of a normal copy and the polarized copy 

 there is a clear strip, which is narrower where the exposure has been 

 stronger. The dog to the left shows greater density of the normal 

 copy than the one to the right, where the bright strip is broader. 

 This strip occurs in the brighter parts in a manner that is the exact 

 opposite of the way it occurs round the outlines of the leaves of the 

 tree and of the bare trunk in the background ; a few shoots are 

 even quite white. Here the strips are found in the darkest parts, and 

 decrease in width towards the right of the tree top, round which a 

 smaller light intensity has been active. 



The wall was more strongly lighted to the left than to the right, 

 and appears slightly darker there, but still it remains polarized, which 

 is easier to see in the original film than in the reproduction. The 

 left side of the tree top shows more halation than the right, while 

 no halation whatever is to be seen in the part of the sky near a, 

 which was subject to the action of light with greater contrasts. Here, 

 however, one would have expected that halation would have acted 

 in the opposite direction, viz. not decreasing in density in the darkest 

 portions, but increasing in the lighter ones. 



The comparatively slight density of the sky near a is striking, and 

 so is the low colour sensitiveness to green (grass and foliage), while 

 the dark blond and dark brown hair of the two female figures show 

 a stronger action of the light, which can be seen better in the original 

 copy. The wall in the background is white, so that here the 

 colour sensitiveness to the red of the bricks cannot be ascertained 



Fig. 6 renders the critical exposure still more strikingly. It repre- 

 sents an interior ; the film was exposed a few seconds, and shows 

 every object in the room polarized, even a large portion of the 

 halation owing to the light from the left window. What is seen outside 

 through the windows has been copied normally ; here, consequently 

 the critical exposure has been exceeded. The halation has partly made 

 the lead setting of the coloured glass appear normal again, while to 

 another portion it has given greater density owing to the action of 

 the light being stronger. A large part of the right half and a smaller 

 part of the left bottom section show differences in density, which 

 must be ascribed to uneven action of the chemical reactions during 

 the time the film was kept. Fig. 5 also shows this, but in a slighter 

 degree; here, however, it is less noticeable on account of the wealth 



