Tessar | Carl Zeiss Jena – 360 mm | f:6,3 | 1911 – The very first Tessar Tessar is probably the lens design most produced ever. Introduced in 1902, it was created by Paul Rudolph, from Carl Zeiss. The construction concept has found applications from large format down to Minox size. Lenses using Tessar’s design reached the order of millions of…
Refraction, Dispersion and Optical Glass for photographic lenses Refraction is a phenomenon of waves changing direction when passing from one medium to another. In a photographic lens that is the case when passing from air to glass and again from glass to air. It occurs also when passing from one type of glass to a different one. They…
Image circle from angle of view and focal length Result is presented with the same unit you used for focal length.
Use this calculator to find out what is the minimum image circle your lens must provide in order to cover a certain film format.
Although published in 1954, this is not a very hard to find book for online purchase. Organised by H.J.Walls and edited by Focal Press it is one of the few books, intended for amateurs, that talks more in depth about optical principles, the nature of light, sensitometry and characteristics of lenses and photographic equipment in general….
Lens/subject/format – an online simulator How it works: You enter the focal length of your lens, film or digital sensor dimensions and the approximate size of your subject. The simulator shows in value and graphically the following corresponding information: The calculation is made in order to fill the frame proportionally. If subject proportions do not correspond to…
Book published in 1905 is an essential source for studying the History of Photography seeing it inserted and as a continuation of the studies on light, photo-sensitive reactions and formation of images through lenses. Phenomena observed and studied since ancient Greece and deepened particularly after the Renaissance. But 700 of its 900 pages are devoted…
Orthoskop | Voigtlander, the second Petzval – Orthoskop | Voigtlander | 1857/58 – This is the oldest lens in my collection. It came from an antiques shop in Santos – São Paulo, in a shoe box, wrapped in newspaper, with a Dagor 240 mm, a Tessar 300mm and some other non important photographic items. Unfortunately two elements are missing…
Ground glass loupe, easy and useful Quite often we want to check focus more carefully in a view camera . To do that, the obvious idea, goes about using something that enlarges the projected image allowing for more precision than with bare eyes to inspect image’s sharpness. Three problems generally arise when using common loupes and…
A digital file is like a score for an image to be automatically played on a printer. Otherwise, a digital print is as material as any silver gelatin picture.
Being a relatively small book, 245 pages, it couldn’t really try to be a comprehensive approach to the vast subject that it addresses. From there the name “a concise history”. But what is interesting in it is that once admitted that condition, there is a insightful history of ideas in photography with some very well…
This is a classic and very useful work from Anselm Adams (1902 – 1984), north american photographer, in which he explains his Zone System. It is a working procedure that starts by evaluating the film exposure considering: