You may sometimes find that the actinometer indicates a very different
exposure from what the eye would lead you to expect. For instance, one
day last September I went to Bothwell Castle, to get a picture I knew of
in the grounds. It was one of those strange yellow days we had then, and
the sun, though shining with all his might, was apparently shining
through orange glass. The actinometer indicated an exposure of thirty
seconds where in good light one would be right. I was rather incredulous.
Thirty seconds in broad sunshine! However, I gave this exposure, but for
my own satisfaction I gave another plate fifteen seconds only.
On developing, the latter was hopelessly underexposed while that having
thirty seconds gave a negative which furnished one of my exhibition
pictures.
I have shown you how to reduce the quality of the light to a certainty,
also how to reduce to rule the exposure with different lenses and stops
on certain classes of subjects, and it remains with you only to guess
correctly to what class the view you wish to take belongs; I can assure
you from my own experience that there is enough uncertainty about that
point to prevent good negatives ever becoming monotonous.
Pages:
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75