This section is from the book "Complete Self-Instructing Library Of Practical Photography", by J. B. Schriever. Also available from Amazon: Complete Self-Instructing Library Of Practical Photography.
393. The landscape or seascape picture with sky is not complete unless it contains the proper cloud effect. The extreme amount of contrast between the light blue of the sky and the dark green of the foreground when registered on the plate with sufficient exposure to secure detail in the foreground, will produce nothing but chalky white sky. Over-exposure, almost a rule with the average amateur, may be overcome, to a certain extent, by employing a slow brand of plates. With these, a short exposure and small aperture is almost sure to give a result that may be carefully developed into a useful image.
Regarding Exposure. The actinic conditions vary greatly with the time of day and the season of the year, as well as with the weather conditions. It is impossible to give a definite rule regarding exposure, except that which comes by practice. A deep, clear, blue sky as background allows of a much longer exposure than one in which everything is of a glittering silver gray. Then, too, much depends on the position of the sun relative to the clouds - the longest exposure being allowable when the sun is at right angles to the cloud.
Double Printing Method. There are two practical methods which may be employed to secure cloud effects in pictures: One is known as the "printing-in" method, and this no doubt, when properly done, is one of the most practical ways of securing cloud effects. This method is many times an absolute necessity, if it is desired to have clouds appear in conjunction with the foreground, because it is not always possible to photograph clouds and foregrounds on the same plate. Results true to nature will be secured, however, when the clouds and landscape are secured on one plate in the proper relative printing value, for then both the clouds and the landscape will be properly and similarly lighted. It is extremely important that the light on the clouds and that on the foreground fall at the same angle and in the same direction. There is nothing so irritating or displeasing as to see a print in which the clouds are lighted from one side and the landscape proper from the other. When this occurs it shows that the worker was either extremely careless or unobserving. Where the printing-in method is to be employed the clouds must be taken when they appear at their best, or when you find them to be adapted for a landscape in which you desire to have them appear. The resulting print, which will be a combination of sky and landscape, is obtained in the printing.
396. Notice Illustrations 40, 41 and 42. Illustration No. 40 is a reproduction from a print made from a regular cloud negative; No. 41 is a reproduction from an ordinary print which lacks clouds, while Illustration No. 42 shows the result of combining the sky with the foreground. Full instruction for the manner of printing-in will be found in Volume IV. Athough Illustration No. 42b is an improvement over Illustration 42a, yet it has a noticeable fault. It will be observed that the clouds are lighted from one direction and the landscape from another, while the river surface shows the blankness of a cloudless sky, instead of the heavy reflections which would appear with such a sky as shown in Illustration No. 42b. To attain a natural effect, the sky negative used should have been inverted - film side out - and the clouds lightly printed into the water space. Or at least the water portion of the print, before developing, (Gaslight paper) should have been toned down to a shade approximating but lighter than the sky tones above. In attempting to improve a foreground or landscape study by the addition of clouds, the aim should be to reproduce nature as near to the truth as possible.
397. A method by which the clouds may be registered in their proper value upon one plate with a foreground subject, is to cut off mechanically a portion of the light from the sky in making the exposure. There are numerous ways of effecting this. One is to employ the focusing cloth in place of the shutter, raising it quickly in front of the lens to make the exposure and then lowering it slowly to cut off the light from the sky while still exposing the foreground. It is possible to use the lens cap in a similar manner; the exposure being made by treating the top edge of the cap as a pivot and raising it slowly from the bottom, in this way covering the upper portion of the lens while making the exposure. There is a shutter on the market known as the Sky-Shade Shutter, which works automatically, giving the sky much less exposure than the foreground, and results secured with this shutter prove very satisfactory. (See Illustration No. 43.)
Illustration No. 40 - See Paragraph No. 396.
Illustration No. 41 - See Paragraph No. 396.
Illustration No. 42 - See Paragraph No. 396.
Illustration No. 42a - See Paragraph No. 396.
398. The ray filter described in Paragraphs 182-196 of this volume can also be used to secure cloud and landscape on one negative. As the ray filter absorbs the blue rays, to a great extent, the foreground secures proper exposure without over-exposing the sky.