1 Under red lighting best quality writing paper is dipped in weak silver nitrate solution, followed by potassium iodide solution, and wiped dry.
2 One side is coated with an 8216;exciting8217; solution of gallic acid and silver nitrate, applied with a brush. The sensitised paper is then dried in front of the fire, and placed in a light-proof holder to take to the camera.
3 Exposure in the camera for about 1-3 min.
4 Development, in the same exciting solution as 2 but diluted to half strength.
5 Fixing in hyposulphite of soda, washing and drying.
6 Another sheet of paper is soaked in salt solution and wiped dry.
7 Under red light it is brushed over with silver chloride solution, and dried.
8 Pressed in tight face contact with the negative in printing frame, the paper is exposed to bright sunlight until it forms a strong brownish image (about 20 min).
The cyanotype process or blue printing was discovered by Sir John Herschel in 1842. Ifs first extensive use was in a book of botanical photograms of British algae by Anna Atkins. Around the turn of the century prepared blueprint paper was available to photographers for making proofs. The process was also used to produce postcards and stereographs of the period. The process never gained any real popularity and so was primarily used as a copying process (as engineers and architects do now). 8230;
The cyanotype printing process , commonly known as 8216;Blue Print8217;, was invented in 1842 by the English astronomer Sir John Herschel, who wanted to create a method by which he could copy or reproduce his calculations and notes. It is one of the oldest and most permanent printing processes. Because this process is simple, inexpensive, and has clear line-production, it plays an important role in the industrial field today as a method of reproducing documents and line drawings. In addition it was also popular among photographers8230;
The term high and low key refer to the dominant prevailing tones 8211; light or dark 8211; used in a picture. A high key photograph consist mostly of white and light tones and some middle tones, whereas a low key photograph is composed predominately of black and dark tones. 8230;
Infrared, photographing the unseen (or simply create very interesting) images.
Discover where a circuit board may be overheating - where hot water pipes are buried in masonry 8211; and where heat loss is occurring through a building8217;s' roof. This would be an ideal use for infrared film. However: let me quash this myth right now! You cannot, under any circumstances, photograph heat loss with an infrared film. Infrared film can see the visible spectrum and also the near infrared up to just under 1000 nanometres.
Creative photographer are always challenging conventions and looking for new ways of coming up with eye-catching images. To kick off the brand new series on Pro Techniques, Lee Frost takes a look at how to get the best out of using infrared film.
Many photographers feel somewhat restricted by conventional, commercial papers. Surface textures are limited and do not always suit the artistic vision of the individual. One way around this limitation is by using liquid emulsions, which can be coated onto many surfaces: paper, fabric, stones, tiles, wood, metal, and more. 8230;
The development time determines the amount of shadow detail. As the development progresses, dark grains begin to appear in the shadow areas, clumping together to form the darkest regions of the print. It is important to decide when to snatch the print from the developer by Judging the shadow density 8211; rather than the highlight detail. 8230; In order to make successful lith prints you must use a chloro-bromide based black and white paper. 8230;
Almost any image from a printed source can be transferred to paper. The best source of material for transfers is a full-color Sunday newspaper supplement. The inks are highly saturated and freshly printed. The paper stock is a lightweight newsprint, and if you wish to transfer duplicate images, you can purchase cheaply several newspapers. 8230;
The photojournalist generally responds to a situation, whereas the studio photographer creates a situation to fit a pre-conceived image. The ultimate control that the photographer has is the manipulation of the image itself. At its most sophisticated, the photographer can take on the role of an director. By combining studio techniques with photo-composites and re-touching, for example, you can achieve the graphic freedom of an illustration yet retain the basic realism of photographic images. Sophisticated image manipulation such as this is found mainly in advertising, where the commercial results justify the often high cost and lengthy technical work.
Combining images: by Sandwiching, Projection, and Multiple exposure
A photogram is a picture made without using a camera; it records not the image of an object produced by a lens but the shadow cast by the object itself i. e. using the photographic printing process but without using a negative. They tend to be strong-silhouetted images. With experimenting you can create a fairly intricate image using marks, shapes and textures. 8230;
The first glossy coated photographic print. In general use c. 1855-1890. Thin paper was first coated with a mixture of whisked egg white and salt, then sensitized with silver nitrate. It was usually printed-out in sunlight under the negative in a printing frame.
Photographic colour print made from a colour negative: the most widely-used form of colour photograph today. 8230;
By using common household materials, you can make a camera that will produce pictures. Making and using a pinhole camera will acquaint you with the basic elements of photography while providing an inexpensive and interesting way to take pictures. This bulletin explains how to make and use two types of pinhole cameras-a cartridge pinhole camera and a can or box pinhole camera. You8217;ll be proud of the pictures you can take with the camera you have constructed.
Strictly speaking solarisation is reversal, or partial reversal, of the image due to gross overexposure. The effect discussed here, although described by photographers as solarisation, is the Sabattier* effect or 8216;pseudo-solarisation8217;. Whatever the name, the effect is easily distinguished 8211; the reversal of weakest densities, and the formation of a thin contour line around strong tone boundaries. It therefore contains some of the characteristics of the tone line effect, but is achieved quite differently. 8230;
There are a number of photographic processes which enjoyed great popularity in the early year of the century. In some the actual photographic print formed only an intermediate stage in the production of the final image. Typical examples are carbon processes, the carbo process, and the bromoil processes. Of these three, the bromoil process is probably easiest to master, in terms of technique and availability of suitable materials. 8230;
Although far more people could now take photographs, for most of the first half of the twentieth century photography really meant pictures in black and white. Everyone now expects to have colour prints from their holiday a few hours after returning home, but 60 years ago a skilled photographer would take several days, at great expense, to get one colour image on to paper. Reaching today8217;s position called for tremendous research 8211; firstly to establish the best principle on which to base a system of colour photography, and secondly (even more difficult) how to put it into practice so that it was simple, inexpensive and gave high quality results. Hundreds of systems for 8216;natural colour photography8217; were put forward, often by fakers and fraudsters. Fortunes were lost trying to launch processes which only partly overcame problems and contained some fatal flaw. 8230;
Good tones are obtained with normally exposed and developed conventional paper prints. Some modern papers even those described as 8216;fibre8217; are liable to give variable results and 8216;blotches8217;. It is recomended that prints are given full exposure, and development, an acid stop, fixed in a simple non hardening fixer, and copiously washed. Work only under subdued lighting. 8230;
A document put together by SPAR Point Group detailing the many ways that 3D data can be captured. What is 3D Data Capture
Includes image examples and a glossary of the 3D Data terms. Georeferenced, non-georeferenced, Laser scanning, Time of Flight, Phase-based, hand-held / close range, photogrammetry, structured light scanners and sonar.