The Photogram, Volume 71900 |
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acid albumen ammonia ammonium apparatus appear artistic bath bichromate Birmingham bromide c.cs calotype carbon carbon print cent chloride chrome alum citric acid cloud coating collodion collotype color Daguerre dark room dark slide developer emulsion engraving exhibition exposed exposure film fish glue fixed focal length focussing formula frame gallic acid gelatine give glass glue glycerine grains grammes halation half-tone hand camera hydroquinone illustrations inches issue kinetograph landscape lantern slides lens lenses light lines London method metol minutes negative Niépce obtained ordinary ounce paper patent Phot Photogram Photographic Society pictorial picture piece plate platinotype portrait position potass practical Price prints reduced reproduction Royal Photographic Society salt screen sensitising sensitive shadows shutter side silver silver nitrate sitter sodium solution stereoscopic Street studio sulphite sulphocyanide surface tone trade transparency varnish washing yellow
Popular passages
Page 92 - When daffodils begin to peer, With heigh ! the doxy over the dale, Why then comes in the sweet o' the year ; For the red blood reigns in the winter's pale. The white sheet bleaching on the hedge, With...
Page 245 - Note on the Art of Photography, or the application of the Chemical Rays of Light to the purposes of Pictorial Representation.
Page 247 - To fix the picture, it should be first washed with water, then lightly dried with blotting paper, and then washed with a solution of bromide of potassium, containing 100 grains of that salt dissolved in eight or ten ounces of water. After a minute or two it should be again dipped in water, and then finally dried. The picture is in this manner very strongly fixed, and with this great advantage, that it remains transparent, and that, therefore, there is no difficulty in obtaining a copy from it. The...
Page 247 - ... the paper. On the other hand, a stronger impression does not require the warming of the paper, for a wash of the gallo-nitrate suffices to make it visible, without heat, in the course of a minute or two. A very remarkable proof of the sensitiveness of the Calotype paper is afforded by the fact stated by the author, that it will take an impression from simple moonlight, not concentrated by a lens.
Page 225 - I have omitted to mention that those preserved by iodine are always of a very pale primrose yellow; which has the extraordinary and very remarkable property of turning to a full gaudy yellow whenever it is exposed to the heat of a fire, and recovering its former colour again when it is cold.
Page 225 - ... kept some weeks before the trial is made) that its sensibility is greatly diminished, and, in some cases, seems quite extinct. But if it is again washed with a liberal quantity of the solution of silver, it becomes again sensible to light, and even more so than it was at first. In this way, by alternately washing the paper with salt and silver, and drying it between times, I have succeeded in increasing its sensibility to the degree that is requisite for receiving the images of the camera obscura.
Page 247 - If the aperture of the object-lens is one inch, and the focal length fifteen inches, the author finds that one minute is amply sufficient in summer to impress a strong image upon the paper of any building upon which the sun is shining. When the aperture amounts to one-third of the focal length, and the object is very white, as a plaster bust, &c., it appears to him that one second is sufficient to obtain a pretty good image of it.
Page 225 - I then spread a solution of nitrate of silver on one surface only, and dry it at the fire. The solution should not be saturated, but six or eight times diluted with water. When dry the paper is fit for use.
Page 83 - I pour upon it, drop by drop, the essential oil of lavender,1 until the bitumen is completely saturated. I afterwards add as much more of the essential oil as causes the whole to stand about three lines above the mixture, which is then covered and submitted to a gentle heat until the essential oil is fully impregnated with the colouring matter of the bitumen. If this varnish is not of the required consistency, it is to be allowed to evaporate slowly, without heat, in a shallow dish, care being taken...
Page 247 - They may be made visible by the process already related, namely, by washing them with the gallo-nitrate of silver, and then warming the paper. When the paper is quite blank, as is generally the case, it is a highly curious and beautiful phenomenon to see the spontaneous commencement of the picture, first tracing out the stronger outlines, and then gradually filling up all the numerous and complicated details.