LENSES In discussing this subject, I will take up only those lenses which have been found most practical in commercial photography.
Lenses used in this connection must have extreme covering power, good depth of focus and fine definition. Anastigmat lenses are, of course, the best for this purpose, although the rectilinear type does very well in many instances.
If one can stand the expense it is mighty convenient to have a battery of lenses, but I would rather have a few and know their good and bad qualities and limits thoroughly than a large number with which I was not entirely familiar. I have so often seen very good lenses lying idle and condemned because the owner did not know how to use them. This applies to portrait as well as commercial photographers, and only goes to show that it is not the lens but the "man behind the gun." For studio work a long focus lens is very necessary, especially in photo graphing furniture, pianos, and the like, and this should be an anastigmat if possible, although an anastigmat lens of eighteen to twenty or twenty-four inch focus runs into considerable money. Nevertheless, it is a good investment. This lens should also be corrected for color, otherwise it would not give the proper results when used in connection with ray filters or arc lights.
Several of the older shops use some of the old-type lenses, such as the Sutor, Somerville, Dallmeyer Rectilinear, etc., but the only advantage I can see in these is that they are cheap, and while they give very good' definition when stopped way down, they have not that crisp definition of the Goerz Dagor, Cooke Series V, Turner-Reich, or Bausch & Lomb II-B Tessar, \Vol lensak Velostigniat and other more modern types.
While there are possibly many other lenses on the market which will do the same work very nicely, I know from experience that those just mentioned are entirely satisfactory.
A good feature in a studio lens, even though not often used, is that of convertibility, as it is often absolutely necessary to have an extreme long focus lens.
For outside work a medium focus lens, that is, about twelve or thirteen inches, two of short focus, one extreme and the other, say, a Series IV Bausch & Lomb Protar, and then a lens of eighteen- to twenty-inch focus is needed. I am not in much favor of convertible lenses for outside work where but a single element is used, as they have to be stopped down so far that they are slow, and barrel or hour-glass effects develop that arc anything but pleasing to a critical person, such as an architect or engineer. For this reason a. "regular lens" is advisable if one can afford it.
Another lens needed when making enlargements direct from small copy or objects, and one which I have found highly satisfactory, is a moving picture lens of about two- or three-inch focus used in connection with a long bellows camera. It gives fine results.
An extreme wide-angle, such as the Goerz Hypergon, is a lens for which there is but little use unless one makes a specialty of photographing large buildings in congested districts. However, a lens of this type or a Series V Protar necessarily must be used in connection with a skyscraper camera, for the reason that the lens is often above or below the center of the plate and therefore has to cut more than the size of the plate.
In photographing interiors a wide-angle lens should never be used unless the quarters are very cramped, as the result is far from pleasing to a customer, although he may not know the reason. It is better to use two or more plates.
It has been found that some of the better classes of anastigmat types make very good wide-angle lenses when, for instance, a 5 x 7 is used on an 8 x 10 or an 8 x 10 on an 11 x 14 plate. In this connection it is well to know that a 12-inch lens may be used very satisfactorily on a 12 x 20 plate. I have made many banquets with 12 x 20 plates, using a 12-inch Goerz Dagor lens. There is, of course, some distortion at the edge of the plate, but the general effect is good.
A lens of soft focus is very nice to have on hand, as every now and then one comes onto a customer, such as an advertising concern, who does not like the old sharp stuff, whereas a picture made with a soft focus lens just appeals to his artistic senses. As a lens of this type is not always available, this little tip may not come amiss: a small piece of black marquisette veiling, tied over the front of the lens, gives a very good imitation.
In commercial studios, where different sizes of lenses are used, ranging from the small wide-angle to the large long focus types, it is somewhat of a task to keep track of the different front boards and lens flanges to fit various cameras. The following are two good systems which are used in two large studios with success.
The better system, to my mind, is to have a master flange attached to the front board of each camera, both indoor and outdoor, this master flange being really the flange of the largest lens used. The other lenses are then fitted with a permanent flange or metal collar which will screw into the master flange. In this way there is a master flange in each camera at all times, and any lens in the shop, in view of its permanent flange collar, will fit any camera. The cost of installing this system is nominal, and any machine shop can do the necessary work.
The other method is to attach permanently a wooden front board to each lens, this smaller front board being of a size to fit into what might be termed the master front hoard of each camera. • In this, as in tbe above case, the lenses are always ready for any camera without any delay.