The Aristo DA-17 Light Head will become an indispensable light tool to you in the many illumination jobs it is capable of performing. With a little experimenting and a little imagination, we are certain you will find still more, and possibly better, methods of using this unusual "Do-All" light source in your operation, than are listed here.
Before making any exposures, allow unit to burn for a few minutes in order to redistribute the mercury vapor inside the lamp. This should be done whenever the DA17 remains idle for several days or weeks, as on a dealer's shelf. Basic Functions
I. Opaque copy photography - For Copying, Microfilming, Slide making, etc. Will handle originals up to 15-1/2 x 18-1/2".
Place unit on a clean matte white background.
Insert copy, centering it within the unit so that complete uniformity of light is assured. Do not use high gloss materials larger than 5 x 7" so that specular reflections into the lens are avoided. Semi-matte and matte copies such as portrait photos, letters, documents, drawings, etc., are ideal.
II. Transparencies, Color or Black & White, up to 8"x 10 " For color duping, slide making, microfilming, etc.
Insert a clean matte white background beneath DA17. A white photo mount board will do very well. Slide the diffusion tray into the top tracks of the unit. Place the transparency on the diffusion, emulsion side up.
Transparency may be held flat with a piece of glass if necessary.
II. Small Parts Photography:
Set up same as for opaque copy. Here, different colored backgrounds, which may enhance the objects being photographed, could be used. A package of assorted colored construction paper will serve nicely. For shadow-free illumination, on objects with cavities or recesses, use DA17 without masking.
If shadows are desired to emphasize depth, texture, or dimension of the object, opaque or translucent masks maybe introduced between the light source and the object on one or more sides of the unit. Masks may easily be made of copyboard. To provide still greater latitude in shadow modeling or composition, these may be made black on one side to absorb light and white on the other to reflect light. Thus, it is possible to achieve an almost infinite variety of shadow modeling effects.
IV. The photography of jewelry and silverware:
Set up as for opaque copy.
Introduce the desired background for the contrast wanted.
To subdue strong specular highlights, for a more pleasing visual effect, introduce translucent masks on all four sides. This is called "tenting," normally employed in photographing highly specular objects. "Tenting" may be done by using white bond or typewriter paper, or better still, masks may be made of white translucent plastic.
V. Photography of Biological, Pathological and Medical Specimens:
Specimens larger than those that could be accommodated in the small DA10 can now be beautifully photographed with the DA17. Any one or any combination of the above masking techniques may be employed to produce the desired effects in the specimen being photographed.
In the case of wet specimens, a white non-glossy rubber sheeting can serve adequately as a background.
One of the important advantages of the DA17 is that the heat rise on the specimen is negligible even on prolonged exposure, thereby preserving its integrity for longer than is possible with any other source. VI. Duplicating and Microfilming Transparencies 35 mm to 14 x 17 X-Rays:
Turn the DA17 upside down, so that the rectangular lamp is at the bottom. Now slide the diffusion tray into the tracks as far as it can go. Insert a clean matt white background beneath the inverted DA17. Place the transparency or X-Ray on the diffuser tray, which if necessary, can be held flat with a piece of glass.
VII. Other Applications:
While foregoing methods of employing the DA17 are the most obvious, they are by no means the only methods to use this unit. For example, the DA17 may be stood on its side or on its end in an upright position for table top photography.
Or try "mug" shots with the subject approximately 18 inches in front of the light. Or for shadow free illumination of hardware or equipment larger than will fit into the unit itself, etc., etc.
The standard W55 rectangular lamp (other lamp colors are available) in which the DA17 is equipped, emits light at approximately 5800 K and provides very acceptable results on the daylight films available.
On others, a white background may turn out with a magenta or bluish cast. In such case, where results are critical, corrective filtering should be employed to bring the lights into balance for the film being used. Also, in spite of rigid controls, a slight shift in the color balance of the lamp may occurs from one batch to another requiring corrective filtering on critical work.
The use of the FLD plus 10 or 20 magenta filters usually corrects for daylight film or the use of 30 M alone. The lamp is rated for approximately 7500 burning hours. Frequent on-off operation will reduce this life to some extent. It is recommended that the lamp be left on between exposures, unless exposures are made infrequently.
The special rectangular lamp with which the DA17 is equipped emits light at approximately 5800 K and provides very acceptable results on any of the color daylight films available without additional filtering. However, if work is exceptionally critical, additional filtering may be employed where necessary.
The lamp is rated for approximately 5000 burning hours. Frequent on-off operation will reduce this life to some extent. It is preferred that you leave the lamp on between exposures.
Care of Diffusion Tray
Wipe occasionally with soft cloth and antistatic liquid, such as No Stat. Do not wipe with dry cloth as fine scratches may
result. Replacement lamps are available. Installation is very simple and takes about ten minutes.
With a normal amount of care, the DA17 will provide years of useful and trouble-free service.
