To make a head and shoulder portrait of good size, say, a 2k-inch head on a 5 x 7 plate, your lens will be about 4 feet from your subject. This is entirely too close for the best results, but you must work this close if you have no other lens.

With a 20-inch lens you will get exactly the same size image at about 8 feet from your subject, which is twice the working distance. The perspective will be much better and the same lens may be used for heads as small as 1 1/2 inches.

If you find the perspective in your work is poor and you wish to correct it by employing a lens that will permit you to work at a greater distance from your subject, you may be at a loss as to what is the best lens for your special use.

There is a very simple rule which gives you results sufficiently accurate for practical use. Suppose you have a good lens for head and shoulder work but want a lens for full figures. The average standing figure is 68 inches. Suppose you wish to make standing figures about 7 inches on 8 x 10 prints. Divide 68 by 7 and the result is 9 5/7 or practically a 10 times reduction. Add 1 to the reduction figure, 10+1=11, and divide the working length of your studio, whatever it may be, say, 15 feet or 180 inches by 11, and the result, 16.3, is the greatest focal length of lens you can use. As round figures will answer for all practical purposes the fractions may be disregarded in these calculations.

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By Cornwell - Photographer Dayton, Ohio

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By Cornwell - Photographer Dayton, Ohio

The same rule applies to heads, taking 9 inches as the height of the average head. By this rule you can determine the reduction you wish to make, whether it be a head, a three-quarters or a full figure, and can quickly determine the focal length of the lens that will produce the result you wish at any given distance from lens to subject.

Suppose you wish to make a group and your studio has a width that allows you to make the group 10 feet, or 120 inches wide. You want the group to be 8 inches wide on your plate so the reduction is 120 + 8 = 15. The rule says add 1, which makes the reduction figure 16. Your working distance is 15 feet, or 180 inches, and 180/16 = 11, so your lens can not have a focal length of over 11 inches to make such a group.

To find the greatest width of group that your 16-inch lens will include, divide your working distance, 180 inches, by the focal length of your lens, 16 inches, and the result 11, is the reduction figure; 11-1 = 10, the actual reduction. Then multiply the width of image on plate by the reduction and you have 8 X 10 = 80, so your 16-inch lens will only include a group 80 inches wide, working at 15 feet.

Practically any information you need regarding focal lengths and working distances can be figured by the formula given below.

D = working distance, lens to subject R = reduction ratio F = focal length of lens S = height or width of object G = height or width of ground glass image

Therefore, any one of the fol-following five calculations may readily be made:

D / (R + 1) = F F X (R + l) =D D / F = (R + 1) R X G = S S / R = G

OUR ILLUSTRATIONS

Environment usually has quite a bit to do with the success or failure of any individual or business.

Dayton, Ohio, has the reputation of being a go-ahead city, a municipality in the habit of doing things in a big way. Cornwell - Photographer is located right in the middle of business Dayton, which may, in a measure, account for his success as a photographer. Cornwell - Photographer has a most attractive studio, where is handled the regular line of studio work; in addition he has from the first made a specialty of home portraiture and has achieved a more than local reputation.

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By Cornwell - Photographer Dayton, Ohio

Cornwell - Photographer firmly believes that the same elements necessary to success in any other line are equally applicable to the conducting of a photographic studio and his entire establishment is conducted according to strictly modern business methods. Coupled with sound business judgment is a keen understanding and thorough appreciation of the artistic and with this knowledge goes the ability to produce results.

Newspaper and other advertising media are made use of, and Cornwell - Photographer keeps his business well before the public.

Eastman Portrait Film and Artura Iris are used exclusively, and Mr. Cornwell pays both products a high tribute as to excellence.

The examples of Mr. Corn-well's work, published in this issue, speak for themselves.

Artura Carbon Black Enlargements retain the contact quality and there is a Carbon Black surface to match the contact print.