The technique photo   


Introduction -Lamps - Technique photo - Plaster's stone-pit - Refuges - Roucy - Paris - Tuffeau's stone-pit - Naours -Mushroom bed - Abyss of Fage - Unusual - Biblio et contact


You will find in this page, a lot of technical details, tricks(things) and other craftiness to become the  Yan Arthus Bertrand of the underground’s photo.


Above all, thanks to the crazy lovers who contributed to the enrichment of this column (among whom Roudoudou who presents high-quality photos :  voir Roudoudou)


*  One thousand excuses: The photos of this site are scanned, reduced, compressed, a whole heap of treatment for the pleasure of the navigation, but indeed on, in depends on the quality. The result is not optimal, far from there. Promised, soon I sets up you logoes which get bigger when one clicks above.



*    Analogique and numérique : There is for all the tastes, but I do not try to promote a technology rather than the other one




*  The colour and the heat of photos :


The flash will look to your photos, a pale complexion, without volume nor character, please , banish him(it). Please , prefer the light produced by the heat of flames, by heightening if need be zones badly lit(enlightened) by small touches of diffuse light with your lamp wipes during the time of exhibition


*  Films  :


Concerning the times of exhibition and the colours, the used film is very important: The fuji 4 coats(layers) tends to fire in the green at the long exhibitions, the Konica towards the blue, while the gold gives one yellow orange of the best effect. To you to be made your own opinion and please , do not hesitate to announce to me your own experience(experiment). The kodak gold extreme reactionary which is the film for holes of the bottom par excellence. The advantage it is that this film is one 800 ISO encodes there 400 ISO. The answer is immediate but decreases in the time.



For device has automatic measure of exhibition, put itself first and foremost diaphragm on 5.6 and to add 2 in correction of exhibition if the flames of candles are VISIBLE because they deceive the computer. What should look in the 15s of exhibition.


*   It is quite vague!


Being moved!!!


The camera’s foot, it is indeed but it is imperative to have also a remote control not to make move the device or then , please , use the retarder. To make(do) the settling (witness of depth of field wanted has to stop work on the automatic devices obviously), use a powerful lamp in spotlight and light(enlighten) a zone.



Not necessities to take a piece of carrot to whitewash your quite new objective of it in focal fixed … The vapor appears when there are distances from temperature, typically the lad who keeps(guards) camera  in the warmth in its jacket. It is necessary to do a stake in temperature of the device.


 Please , prefer the use of a waterproof house for your device, with a package of dessicant (Silicagel by ex) to transfer the humidity. On the other hand, he should stay far from you, in the COLD, finally, has ambient temperature.




*  The photo opposite was realized in the Career of Triel's plaster on the Seine, with 3 acetylene torches, some candles the effects of which are rather subtle, is a lighting in the torch (for the bottom of the tunnel, in height). Please , do not hesitate to sweep the zone with your torch, otherwise you would risk to make appear too clearly the bundle on your photo.


This photo was realized with a  Nikon F501

and an objective 50 mm F1,8.

 Time of break: 30 Opening: F4,0 Film 400 Iso

 (please , do not choose a too much brought up sensibility, you will be disappointed by the grain of the photo



*   The photo opposite, realized also in the Triel's stone-pit plaster on the Seine innovates not at all with regard to the photo above. The interest lives(lies) in its extraordinary copper-colloured tint. This time, the torch was not used in light of supplement. The small candles dish warmer arranged here and there, come to heighten the front plan and to contribute to highlight the front plan, even if one can regret the too net effect of spotlight.


*   The digital camera does not still offer all the flexibility of use of a reflex. The gradations of colour are more unrefined and the too clear zones are going to be translated by big white wall cupboards. But if one takes into account the simplicity of use of the numeric(digital), and the possibility of retouching colours, luminosity and contrast in its suitability, one can nevertheless remove from it some satisfactions. The photos of the Abyss of Fage and Roucy were realized with one Olympus Camedia C-2000 Z (since, I changed device and that goes better!!)

*  The noise: You can respect a religious silence during the recording, or dance and sing loud, you will always have this mixture of unpredictable elements which are a part of made measures and of interfaces caused by the electronics of the device.


The Background noise


No pixel is susceptible " to count " the same number of photos as the other one, even if they are exposed(explained) to the same source.

The Noise of Reading    The Noise of the Treatment


These noises intervene in every stage of the process: The signal created by the light striking a sensor is amplified and converted (even interpreted) in numerical value.



Remark: Even when there is no light arriving on a sensor, electrons accumulate gradually in the pixels. Called Dark Noise, the signal which this phenomenon creates is imperceptible of that produced by a source of light



*    SILENCE !!!


The photography in very weak light is strongly susceptible to contain of the noise. The content of this noise can be controlled to a certain extent by the length the exhibition and by the sensibility of the sensor. Usually, a CCD with weak sensibility (slow) and a long exhibition produce an image of higher quality than a shorter exhibition with the sensibility of high CCD.


To finish, another factor should be taken into account. The compression JPEG can increase the noise in an image by making(doing) the average of the colours of a group of neighboring pixels. If it is available, a not compressed format of image should be used.

*       The regulation of the white


Without entering too technical details, digital camera needs to establish a base on which will be estimated the proportions of colours (the sum all the colours is the white). For any photo the white should be so determined, and photoscopes is slower than their cousins argentiques because these last ones leave the care of this step(method) with the film.


The white being affected by the surrounding lighting, the device should so take into account this light to compensate for so necessary effect of it. Most of the recent devices offer the possibility to adjust the regulation of the white. For my part, I leave the mode auto and I find the copper-colloured tint of argentiques photos.



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Introduction -Lamps - Technique photo - Plaster's stone-pit - Refuges - Roucy - Paris - Tuffeau's stone-pit - Naours -Mushroom bed - Abyss of Fage - Unusual - Biblio et contact