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.
Selection Of Clouds. If it is your intention to make a series of cloud negatives to "print-in" with the foregrounds of other negatives, you must make a very careful selection and secure cloud effects that will harmonize with the foreground subject. Clouds that typically belong to seascapes would be entirely out of place when the foreground represents a mountain scene, for instance. The importance of clouds will be well understood when you stop to consider that white paper can never truly represent the sky portion of any landscape or other out-door subject. There was a time when many amateurs would have one stock cloud negative and use this negative for every subject, but this error is not common now among serious workers.
Cultivating Observation. Read the instructions which follow, cultivate your faculty of observation and notice carefully at different hours during the day the various lightings on the clouds. Whenever you have an opportunity to observe cloud effects, do not fail to carefully note the difference between clouds in one class of landscapes and those which go with seascapes or other landscapes. Do not forget that different climatic conditions have much to do with the forms of clouds. Heavy storm clouds should not be employed with scenes representing a bright sunny day.
Fair Weather Clouds. In fair weather the clouds have a very delicate thread-like appearance and settle at a great elevation, sometimes resembling mere smears of white in a clear blue sky. At times these streaks are parallel, sometimes intersected and often may be accompanied by a light breeze. Clouds of this type are called Cirrus clouds and most successful results will be secured in photographing them by using orthochromatic plates and ray filter. Cirrus clouds give a most useful variety of negatives, as the direction of light is so faintly indicated that few mistakes are likely to occur when employing them with almost any evenly lighted landscape.
402. A denser form of fair weather cloud which rolls along in strong majestic masses, towering upwards from the horizontal base is called Cumulus cloud. This cloud forms one of the most striking types to employ, as its definite shape is very often useful in composition. Some difficulty, no doubt, will be experienced in securing a satisfactory negative with these clouds on a strongly lighted foreground, for in most cases they are strongly lighted themselves, and unless the direction of light is identically the same in both the sky and foreground, the result of the combination will be extremely bad. Before a rain, the masses of Cumulus increase rapidly and become fleecy and irregular in their form.
Wind Clouds. The Stratus is well indicated by its name, and is the cloud appearing lowest or nearest the horizon. This type of cloud usually precedes bad, foggy weather, but you will find it very effective if you can photograph it properly, especially at sunset.
404. The combination of the Cirrus and the Cumulus clouds form what is termed the Cirro-Cumulus, rounded in shape, appearing in detached horizontal layers. The upper portion of this cloud is some times called "Mare's Tails," and it always indicates a fair amount of wind. This
Illustration No. 42b - See Paragraph No. 396.
Illustration No. 43 Skyshade Shutter See Paragraph No. 397.
Illustration No. 44 Reflex Camera.
See Paragraph No. 460 cloud is generally whiter and much better defined than the Cirrus and is also much easier to photograph, owing to the fact of its being less actinic in color.
405. A combination of the Cumulus and Stratus clouds form the Cumulo-Stratus, which is stronger and denser than the Cumulus. It foretells stormy weather. When the Cumulus cloud thickens rapidly upon the approach of wind and rain it takes on all the characteristics of the Cumulo-Stratus.
406. The Cirro-Stratus lies in longitudinal streaks and is usually called the mackerel-back sky. Windy and tempestuous weather is very apt to follow the appearance of this cloud.
407. All of these clouds appear most frequently in conjunction with the blue sky and with the exception of a sun lit Cumulus generally need an orthochromatic plate and ray filter for correct rendering. Cumulus may also need this attention, but the great wooly masses of clouds are sometimes so strongly defined that the use of a screen would effect "over-correction."