PHOTOGRAPHIC 8×10″ ENLARGER FOR B&W NEGATIVES

This proyect dates from ca. 1992

I have always believed that to obtain the highest optical quality in a photograph, the camera used is irrelevant. The only two elements directly related to the quality obtained are the film and lens used. A more or less sophisticated camera can help us with ease of use, accuracy of its mechanisms, weight or other characteristics, but in no way will it improve the optical quality in a photograph that we can obtain with a shoe box perfectly sealed to light, with the same lens and film of the most advanced camera.

With that principle in mind, I proposed the project of the enlarger I present.

In the book “The Negative” by Ansel Adams, an enlarger for large format negatives appeared. The same in its origin, worked with tungsten light, although lately he had used it with cold light. My curiosity and desire to obtain the maximum detail in my photographs, led me to investigate and test that complex format of 20×25 cm. So it is that I began to building this enlarger.

Photographing the world with a 8×10 inches camera is not an easy task. The considered normal lens is a 300mm; the same focal lengh for a quite a telephoto on 35mm!!!

The depth of field with a “telephoto” of that caliber is non-existent and should be focused with great precision. The film is four times more expensive than the 4×5″ format. And therefore, not so many film sheets are loaded or shoot in a given situation of changing light in the natural environment where I moved.

I do not want to say a 8×10″ camera is not a good instrument, but an instrument somewhat more complex than usual that can be very useful for some applications by the appropriate lens and resources.

El motivo de esta entrada, es sólo para demostrar que es posible y animar a todo el que tenga algo interesante que decir (fotografiar) con un instrumento de ese calibre.

The reason for this entry, is only to demonstrate that this build is possible and encourage anyone who has something interesting to say (photograph) with an instrument of that caliber.

At the bottom left, the tube through which the cooling air gets in from a fan. In the upper left, through which the air was expelled.

Detail of the tungsten bulbs. The temperature was so high that the compartment was cooled by air that entered through the lower mouth and exited through the upper one. Both mouths were made with trap doors to catch the light and avoid light pollution in the dark room.

Detalle del portaobjetivos. En la fotografía se observa el objetivo de 300mm. f:5.6 que utilizaba para la toma. Posteriormente lo reemplacé por otro de la misma focal, de segunda mano, que era específico para reproducción reprográfica.

Detail of the lens holder. In the picture is seen the same lens I used for shooting, which later I replaced it with another of the same focal, second hand, which was specific for reprographic reproduction.

The negative holder allowed film up to 30×30 cm. There is a wood ribbon on the edge of both frames, which made it a trap door so that the light did not contaminate the dark room.

The displacement of the focus lever was carried out by friction through a semi-hard rubber by the central lane that is observed at the bottom of the image.

Bottom Line

Overall, I was very happy with the construction, finish and operation of the appliance. What disappointed me most was the insignificant improvement in detail that meant using the 8×10″ format instead of 4×5″.

I obtained fine enlargements to 20×24″ very correct and free of grain, but that absence of grain, in a way they gave an appearance of “less detail” or soft. The enlargements to that same size from negatives 4×5″, produced a micro grain that provided the sensation of more acutance and detail.

In a way, this phenomenon is similar to that when using classic Kodak TriX vs. the modern Kodak T-Max. The total absence of grain of the T-Max, gave results in that apparently the images “lacked detail”.

By | 2017-04-21T10:04:22+00:00 March 14th, 2017|

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