Enlarging and Developing Digital Camera Prints in a Dark Room

While to develop a negative we only need a black bag, a barrel and a sink, enlarging and developing prints requires a closed space which can be used (at least part-time) as a laboratory. The place has to be sufficiently spacious and ventilated so that a person can work comfortably for some hours and can be totally darkened. White light dispersed in the darkroom because of a leak in the enlarger or exterior light influences negatively in our work, causing the appearance of veiling in our image. It is advisable to condition the doors and windows to avoid any exterior light.

It isn't strictly necessary to have running water in the darkroom; an electrical outlet is needed, a solid and spacious horizontal surface, shelves and the proper elements of a lab.

Regarding the security light of the darkroom, yellow or red colored light has no effect on the photographic paper's emulsion. Photographic paper has different sensitivities according to the brand and type; it is convenient to make sure that the color of the security light is the adequate for the type of paper we are using. The dispersion of the safety light in the darkroom isn't harmful, as long as the intensity level doesn't cause veiling in the paper. We can make a test of the security light leaving a piece of photographic paper on the table for three minutes, partly covered and partly exposed to the security light. If after the developing we can see a difference in the two zones, it is necessary to correct the color or intensity of the security light in the zone were paper is worked with.

Enlarger

Schematically, the enlarger is a projector of low strength and variable height with which we can regulate the size of the projected image. It is constituted of a head that can be lifted up and down along a vertical backbone on a horizontal base .

In the interior of the head is the light socket and the lamp , a condenser which concentrates the beam of light downwards, a negative holder were we place the film, a lens with it's corresponding focus mechanism and diaphragm , and a red filter that is between the beam of light to be able to place the paper without exposing it.

Regulating the height of the head we decide on the size of the enlargement of the negative. The intensity of the light on the base diminishes as the enlargement factor is increased. For every enlargement factor there is a corresponding position in the focus mechanism of the image of the negative on the base. Therefore, with the enlarger we regulate the size of the image, focus according to the enlargement factor and regulate the exposure level of the photographic paper on were we project the image of the negative. The exposure level depends on the exposure time and the selected aperture. The format of an enlarger defines the maximum format of the negative that can be projected. The greater the format, the heavier and larger the enlarger is. With a medium or large format enlarger we have access to all the inferior formats through a change in the condenser and lens.

The negative holder of the enlarger defines the working format. For medium and large formats, the film is kept flat between two crystals; in 35 mm, on the other hand, they aren't necessary and therefore we eliminate four surfaces that are susceptible to spots and scratches.

The lens of the enlarger is it's most important piece, and is acquired separately. The optic quality of this lens influences on the image. The detail, the sharpness and the contrast of our developed negatives depend in first place on the quality of the camera's lens. An excellent lens on the enlarger can't get detail out of a blurred negative; the fine detail of a high resolution negative can be limited by a medium quality enlarger lens. Therefore, the quality of the lens of the enlarger has to be coherent with that of the camera.

For analogous reasons which we saw in7.1.6, the lens for enlarging that is considered normal in 35 mm is a 50 mm, for 6 x 6 is a 75 mm, and for 9 x 12, a 150 mm.

It is important that the enlarger has a certain mechanical and optical reliability: the negative holder's plane and the base always have to be parallel; the focus mechanism can't be loose; if we turn on the enlarger without the negative holder the intensity of light has to be homogenous throughout the length and width of the image at any aperture of the diaphragm; the condenser and the crystals of the negative holder can't be scratched or have dust specs; the head of the enlarger can have leaks pointing downwards.

Developing a Digital Film

It is convenient for the "dry" are of the lab, were we have the enlarger, the paper and the negatives, to be a certain distance from the developing zone, to avoid accidental splashes. For the developing we need a set of three trays with their respective tweezers, a thermometer and the liquids which are going to be used: developer, stop bath, and fixer. If we don't have running water, a fourth tray full of water is needed to store the prints until they are washed.

Photographic Paper

The principal main material in the printing lab is printing paper, commercialized in it's different formats, from 9 x 13 cm to 50 x 60 cm or in rolls. A sheet of photographic paper is composed of a base , which gives the paper it's physical characteristics, and an orthochromatic low sensitivity emulsion, who's contrast can vary notably.