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A l'attention de tous les technocrates spécialisés utilisation et connaissances appareils photos ici, mais qui lisent aussi parfaitement l'anglais
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suggestion :
j'ai trouvé tout ça très intéressant, en complément au cours d'optique simplifié que nous a donné OlivierC ici
et si...ce que je mets ici a aussi un intérêt (je traduirai): j'aimerais reprendre les explications complètes (sans les parasites) d'Olivierc...en y ajoutant un peu des origines du 24x36 et du 50 mm (pour les béotiens absolus et ceux qui aimeraient se raffraîchir la mémoire.)
et pouvoir mettre tout ça quelquepart : en accessible (une page spé du
[Glossaire]
par exemple ?)
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....EXTRAITS ....
Oskar Barnack wrote an article about how he invented Leica camera in issue #1 of the magazine Die Leica. The story was like this: Oskar Barnack was working on a motion picture camera at Leitz in 1912. He made some postcard size enlargement from the 18x 24 frame of motion picture film. He was pleased with the quality of the print, but not quite satisfied with the small size, he came up with a simple solution by doubling the frame into 24x36 and invented Ur-Leica, the rest is history
Before Oskar Barnack, there was 24x36 format camera, but did not suceed.
It was Oskar Barnack Leica which popularized 24mmx36mm format.
The movies used an 18x24mm format and Barnack had the insight to double the length for the Ur to 36mm while keeping the width steady. This way, he could use pre-existing film but by increasing the size, was able to produce sharper negatives. He is the father of the 24x36mm film !
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Because movie directors liked the perspective of the 50mm lens on the 18x24 frame [color=#](diagonal=46mm)[/color] it was the "standard" movie camera lens. Everybody, including Leitz, made them. But it would cover a 24x36 frame so it was easy enough to design a camera that would use an off-the-shelf lens.
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The dimensions of 35 mm film are derived from the classical (Greek) idea of pleasing composition. In the smaller formats in the beginning of the 20th century I think there was either the 6*6 (square, ratio 1:1) or the 6*9 (rectangle, 2:3 ratio), reflecting this calssical idea. When Barnack conceived the Leica, it was natural to select the 2:3 ratio as the image format. As the short side is fixed at 24 mm by the width of the film and the perforations, the long side had to be 36 mm.
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I suspect (correct me if I'm wrong) that the later rollfilm formats that do not obey this 2:3 ratio, e.g. 4,5*6 and 6*7, were conceived to better fit standard American and European photo paper sizes. If you print 35 mm on 'Letter' or on 'A4' you always have paper left at the side. If you print 4,5*6 of 6*7, the fit is much better.
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bonne lecture....LOL
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Matériel Photo : minimaliste et numérique : PRAKTICA DCZ 5.4
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Oh c'est surtout que ces photos n'avaient pas d'objectif a etre vraiment montré y'a qu'a voir les drap atroces utilisés.
Mais a une epoque on avait pas de mec sur ce site et c'etait tres pesant de voir du seins a longueur de topic  |
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Pourquois pas le
Grand angle
mais....n'hesite pas a abuser...déforme et déforme encore...Utilisez même le reflet genre(miroir ou autre artifice) Kertez qui faisait des choses magnifique..vous pouvez minimaliser...faire du détailles ou jouer sur la matiere(drap,eau,sable...)les possiblité sont carrement illimité!
A vous de jouer! |
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je découvre le forum...je viens de voir la date de poste....J'interviens uniquement ou j'ai le sentiment de contribuer un tant soit peu a quelque chose...La visiblement...pet de lapin!cordialement |
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