Fourth.—A graduated scale on each screen adjuster makes it easy to always insure absolute accuracy in determining the distance of the screen plate from the wet plate.
Fifth.—The simplicity of construction and excellent workmanship of the entire holder, being made, as it is, in the factory of the famous American Optical Company.
And, altogether, it is an ingeniously designed and beautifully constructed holder, which will be found of indispensable aid to the practical photographer.
These holders are thicker than the ordinary plate holders, and if it is desired to use them on a camera the ground glass of which is focused for the ordinary plate holder, a new ground glass frame is necessary in order to adjust the focus. When ordering a holder to fit a camera in use, send the old holder or the old ground glass frame, so that the new ones can be made to fit the camera. Also state the size of largest and smallest screen plate to be used in holder.
It is made in various sizes. Prices as follows:
| Frames only; for Ground Glass. | ||||
| 8 × 10 | size | $15 50 | $1 50 | |
| 10 × 12 | " | 21 00 | 1 50 | |
| 11 × 14 | " | 26 50 | 1 88 | |
| 14 × 17 | " | 29 00 | 2 25 | |
| 17 × 20 | " | 32 50 | 2 63 | |
| 18 × 22 | " | 36 00 | 2 63 | |
| 20 × 24 | " | 40 75 | 3 00 | |
If adjustment from the outside of holder is desired, add $2.00 to above prices.