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.
Cloth For Flashbags. In use the flashbag is securely tied so that practically no smoke escapes from the flash, excepting that coming through the pores of the cloth, which is unavoidable. The cloth must not be heavy enough to cut down the intensity of the light too much, nor so light that it will not hold most of the smoke; therefore, in the flashbags on the market, the medium weight of cloth is used. This cloth must be of an excellent quality, to take the fire-proofing well and permanently. Poor grades of cloth do not hold the smoke and are not so safe to use. The flashbag, therefore, must be made most conscientiously and carefully.
Diffusion Of Light. In use, also, the light of the flash illuminates the whole flashbag like a Welsbach mantle, and diffuses and spreads the intense light in all directions. For this reason this form of flashlight is most remarkably superior to the open flashlight for actual photographic work, even leaving out of consideration the elimination of the smoke. It is destined to take the place of all open flashlight work.
Fire-Proofing Flashbags. Just a word about fire-proofing of flashbags before taking up the next topic. There are numerous methods of fire-proofing, or so-called fire-proofing. The disastrous results experienced by those photographers who thought they could save money by doing their own fire-proofing and making their own bags proves that it is wise to leave such important matters to those who know how to do it properly. It is true that almost any kind of fire-proofing will last for a short time, but, unless it is done permanently, the bag imperfectly treated may blaze up at the most unexpected time and cause untold damage. A concern that makes a specialty of making flash-bags for use in the most particular places will be absolutely certain that its fire-proofing will be of the permanent quality. Flashbags are things that no photographer has any right to make in a crude way, thus endangering the property of others.
Classes Of Work. Now the question is asked, how are flashbags used, and for what particular kinds of work? Let us divide their use into two classes - small work and large work. By small work, we mean the use of a two-bag outfit for portraits, groups, dinners and weddings, mostly in studios, homes, churches, social halls, leaving all hotel and club work, whether large or small, in the class of the large worker. The latter operates almost exclusively in hotels and clubs, and most of his work is in photographing banquets and other large social events. (These two classes of work are distinctive, and the same photographers seldom do both kinds to any extent; so we will treat of them separately.)
Professional Photographer's Equipment. In the studio one flashbag can be used to advantage when the reflector is employed. Ingenious devices are being made to enable the operator to make repeated flashes without the trouble of emptying the smoke each time. But if the studio photographer is going to make the most of his flashlight opportunities, he must be prepared to go into his patron's home to take interiors, dinners, weddings, etc., without giving any annoyance. In this way a dozen negatives can be made in the home to one made in the studio. For this work he will need only a two-bag outfit with electrical fittings so that he can use batteries in case the home is not fitted with incandescent current.
427. The regular studio photographer would be very unwise to try to get the large banquet work in hotels, unless he is willing to equip himself thoroughly for this important work. The average studio man is content to confine himself to what two or three bags can be made to do. For group work three bags are better than two, just as two are better than one, because it is necessary to get a strong side lighting to give good modeling. In all two or three-bag work the heaviest charge is placed at the side, with a weak light in front of the group, behind the camera.