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.
Different Brands Of Cramer Plates And Their Uses. Cramer Crown Plates are the most rapid plates made. They work with great softness and shadow detail, which qualities especially recommend them for focal plane shutter-exposures, hand cameras, and all instantaneous work. For large negatives and groups in the studio, and for exposures in a poor light or with slow lenses, they should always be used.
Cramer Banner X Plates. Are very rapid with great latitude, giving quick printing negatives full of detail, which produce brilliant prints with perfect gradation from the highest lights to the deepest shadows. They are the most popular plates for general use in portrait photography.
Cramer Blue Label Plates. Made especially for those who prefer plates with more vigor and slightly less speed than the above.
603. Cramer Anchor Plates, of less speed, giving negatives of great clearness and density Mostly used for commercial work and copies.
Cramer Isochromatic Plates. The universal use of the Isochromatic plates would be of great help in the universal production of better photographs, as they will always give as good results as can be obtained with ordinary plates, and in the great majority of cases far better results. Thousands of photographers do not realize what Isochromatic plates will do for them, or believe that they are more difficult to manipulate. A fair trial will show what Isochromatic plates will accomplish and prove that they are no more difficult to handle than the ordinary plates.
606. Photographers at present are not concerned with the reproduction of color as color, but with the reproduction of color as black, white, and the intermediate tones of gray, and as the ordinary dry plate is most sensitive to the ultra violet rays, (these rays being totally invisible to the eye), very sensitive to violet and blue, while almost totally insensitive to green, yellow, orange and red, its reproductions of color are outrageously false, and only put up with at all because we are accustomed to such false renderings.
607. The Isochromatic plates being less sensitive to the ultra violet, violet and blue rays, and more sensitive to green, yellow and orange, give far more truthful reproductions of color, even when used without a screen or ray filter, while a very pale ray filter will entirely eliminate the ultra violet rays, and subdue the action of the violet and blue, giving time for full action of the orange, yellow and green. The use of a ray filter on ordinary plates is of no benefit, as these plates are not color sensitive.
608. Portrait photographers are particularly slow to realize the value of Isochromatic plates in studio work, because they believe there is no advantage in their use without a screen, while the doubled or trebled exposure needed with even a weak screen would make their use impracticable. There are, however, marked advantages in studio use, notably when photographing blondes, blue eyes, colored costumes, and as a help to the more truthful rendering of complexions, due to their sensitiveness to yellow and orange.
609. Their advantages in the field are so great, that if once compared with ordinary plates they will always be used, for they give detail when detail was lacking in foliage and foreground, clouds that will print without reducing or dodging, show distant mountains, invisible on ordinary plates and make prints that show nature's colors translated into their true monochrome values.
610. For commercial work, interior work, and home portraiture the use of Isochromatic plates is indispensable. They show grain in wood and design in colored fabrics, detail in frescoes and colored decorations, and are particularly adapted for copying paintings and showing differences in the values of colored costumes and backgrounds in at home portraiture.
611. The demand for Cramer's Isochromatic plates is steadily growing, due to the increasing knowledge of their advantages. They can be handled in the same way as ordinary plates, except that holders should be filled and developing done further away from the dark room light, unless it is sufficiently subdued. Develop the Isochromatic with any standard formula for Cramer plates.