By Rob Douglas | Published
Colonel Alexander Greenlaw (1818 – 1870)Alexander Greenlaw was born in London , and at the age of seventeen, joined the Madras infantry as a cadet . He was posted to Trichinopoly in Madras . His interest in photography dated from before 1855 , when he first exhibited photographs at an exhibition for art and industry in Madras. He used both paper and glass negatives to make his photographs but his legacy is his simplification of the Calotype process and of course his Calotypes many of which still survive . He doesn’t claim to have invented it but it is the process he used to cope with the heat of India , and it is the process that he used to produce his beautiful and extensive series of Calotypes depicting the ruined city of Vijayanagara in South Western India . These were a very large format measuring 16 x 18 and 16 x 20 inches. Greenlaw was praised for his artistry and for a detailed account of his work there is no better place to look than Vijayanagara Splendour in Ruins by George Michelle. If you do search this book out there is a picture of Greenlaw sitting amongst the ruins in plate 17. The earliest account of Greenlaws Process was carried in Photographic News in January 1869 , also in the 8th edition of John Towlers book the Silver Sunbeam in 1873 which seems to use Greenlaws own words . There is also an account in the 7th edition of Abneys Instructions in photography dated 1886 . This is very late for a procedure that had peaked in the mid 1850s. Indeed it was still being cited in the early 1900s. Here we are in the 21st century and it is still viable. From the Silver Sunbeam . 8th edition 1873. By J Towler. THE CALOTYPE PROCESS — BY COL. A. G. GREENLAW. First examine and select thin negative paper, and reject all that show any irregularities, holes, patches of unequal density, etc . 528 THE CALOTYPE PROCESS. Iodize. Make a solution of — Iodide of potassium . Bromide of potassium 1,000 grains. 800 grains. (For much foliage the latter may be increased to 450 grains.) Distilled water 40 ounces, and add enough of pure iodine to give the solution a dark claret colour. Then filter. Into this place as many sheets of paper as you can do easily, being careful that no air-bubbles exist. Allow the papers so immersed to rest for one hour ; then turn the whole upside down, and hang the sheets up to dry, taking off the last drops with white blotting-paper. This may be done in diffused light. When dry, place sheet over sheet evenly in a portfolio in which no other papers, except blotting-paper, are placed. They are then iodized a dark purple, which will keep any time. They, however, turn a light brown colour. Be sure, in working, that nothing touches the paper, for the very slightest touch is sure to cause a stain in the development. Now float a sheet of your iodized paper on this (smooth side downwards) until the purple has turned an uniform yellow, which is iodide of silver. Allow it to rest for one minute ; after this, remove and immerse in distilled water, where it should remain for two or three minutes ; if to be kept for some time, remove to another dish of distilled water. Place now on clean white blotting-paper, face up ward, and remove by blotting-paper all moisture from the surface (these sheets can be again used for ironing out the wax by-and-bye) ; then place between blotting-paper, or hang up to dry ; when quite dry, place in your dark slides. Sensitizing Solution. Nitrate of silver . Glacial acetic acid Distilled water . 24 ounces. . 24 ounces. 40 ounces. Development. Gallic acid . . Spirit of camphor Distilled water . 200 grains. . 1 drachm. 40 ounces. THE CALOTYPE PROCESS. 529 This is a saturated solution of gallic acid ; it soon de composes ; the spirit of camphor is added to preserve it. When about to develop, filter, and add to every five ounces one drachm of the following solution : — Nitrate of silver 30 grains. Glacial acetic acid . . 3/4 drachm. Distilled water 1 ounce. Pour into your dish quickly, and immediately float the picture side of your paper, which is slightly visible, on it, being very careful that there be sufficient liquid to pre vent the paper touching the bottom of the dish. Constantly watch it until the picture becomes visible on the back, and the paper has a kind of brown, greasy appearance. Continue the development until, in holding up a corner when the sky is before the light, you cannot see your finger when moved about between the light and the paper. If it is not dark enough before the gallate of silver decomposes, you have under-exposed. Decomposed gallate of silver ceases to develop. Do not, when examining your paper, lift more than the corner, as an oxide of gallate of silver forms rapidly on the surface like a crust, and, on replacing your picture, it causes innumerable marble appearances ; so also if you do not place your paper speedily on the solution in the first instance. It may be removed by drawing a sheet of blot ting-paper over the surface of the solution. Remove to a dish of common water, and wash out the brown tinge caused by more or less decomposed gallate of silver. When well washed, you may Fix it by placing it in a solution of hyposulphite soda, one and a-half ounce to one pint of water, till every vestige of the yellow iodide of silver be removed, after which wash in eight or ten different changes of water ; you have then a fine, clear, and dense negative. To render it suffi ciently transparent for printing you must proceed to Wax it This is done as follows : — Place it, when dry, face downwards on clean blotting-paper ; upon it put a sheet of blotting-paper, and pass a moderately hot iron over it; this is to ensure the picture being perfectly dry be fore waxing. Now remove the upper blotting-paper, and pass the iron over the picture, following the iron with a piece of white wax until the whole picture is saturated ; do each picture thus. If travelling, you may wax all your 530 THE CALOTYPE PROCESS. Sheets together like a block, with a piece of clean blotting-paper waxed to the top and another to the bottom. To print from it, you need to remove all the wax you possibly can by placing a sheet of old, used blotting-paper, and passing a hot iron over it, and repeating it till not a vestige of wax appears on the blotting-paper (use red, as it shows the wax spots better than the white.) I have used this process for years in India, and find it most simple. I obtained the first prize for my pictures so taken at an exhibition. With cleanliness it is certain. Modern paper. Canson marker , Canson calque , Canson Vidalon , clear print 1000 , Ruscombe Timothy 2. Bienfang 360 will probably work but I haven’t tested this . The Canson marker has recently suffered with spontaneous development (2015). You may be lucky and find a pad that works . But it looks as if they have added something. The clear print produces weaker calotypes the blacks aren’t very good. The Canson Calque needs to be immersed at all stages due to very rapid curling. Timothy 2 seems to work well but needs more testing. Cut to size . Iodiser Distilled water 1137 mill Potassium Iodide 64.8 grams = 5.7%. Potassium Bromide 19.4 grams to 29.2 grams Or 1.7 to 2.5% (2.5% for foliage ). 500mill of distilled water 28.5 grams of Potassium iodide 12.5 grams potassium Bromide. The free Iodine is used as an indicator , the paper mottles and then clears . In practice it is another unpredictable variable as well as being a nasty chemical to handle so leave it out .My only failures with this process have involved Iodine . Filter. Feed the paper in to the solution carefully avoiding air bubbles. Leave for one one hour shuffling the paper every ten minutes. Hang up to dry by one corner with a piece of blotter on the opposite corner to prevent streaking. It also dries out quicker this way . It can be stored in a cool dry place and will last for years . It will colour with age too , but this is not a problem it has no detrimental effect. Sensitizer Dark room and red light ! 1137 mill distilled water Silver nitrate 71 grams 6.25% Glacial acetic acid 71 mill 6.25% 160mill distilled water , 10 gr silver nitrate 10 mill acetic acid. Filter. Mark the front of the paper and float for 5 minutes on the sensitiser . Then wash for 5 minutes in 2 baths of distilled water . If using the thicker Ruscombe Timothy 2 then wash for 2 x 10 minutes. This removes the potassium nitrate. Blot gently with clean blotting-paper. Place between blotters , place in a large printing frame to dry. With the frame inside a film changing bag. I usually sensitized in the evening and use next day . In the morning I place the sheets of paper in the dark slides sandwiching between two sheets of glass. I find that the top glass prevents the paper being sucked forward when you remove the slide for exposure and that horrible sound of the paper being scrunched when you replace it. Exposure Canson marker 11 seconds at F4 Ev14 full summer sun. Other papers 23 seconds at F4 full summer sun. Canson marker 6 minutes at F22 EV13 full summer sun. Other papers 12 minutes at F22 full summer sun. Development 1.13 % gallic acid 10% spirit of camphor The camphor is used as a preservative. Leave it out. In practice I use a 0.8% solution of gallic acid dissolved in warm distilled water. Let the water cool before development. Heat only accelerates the process. To each 100mill of this add 2.5mill of an intensifier consisting of 28.4 mill distilled water. 1.9 grams of silver nitrate 2.9 mill of acetic acid. Add this to the gallic acid prior to adding the paper. Float or immerse the paper. There is usually an outline on the paper when removed from the dark slide. Development is quite fast. Indeed very fast if you over expose. You will see it come through the back of the paper much faster than other processes. Because of the silver nitrate in the developer the negatives can be dense, indeed some of Greenlaws negatives can only be read by transmitted light. They often take a long time to print . Wash and fix etc as usual. Wash very well afterwards. Wax if required , although this can make the resulting print worse with some papers . I have found that this method gives you a 24 hour window to make your photos and develop. I have a feeling that you may get better longevity with a more thorough wash after sensitization. Replenisher . The sensitiser will eventually become weaker so it needs to be replenished. If you follow Greene’s instructions a replenisher for this process would consist of Silver Nitrate 12.5g Glacial Acetic Acid 6.25 mill Distilled water 100 mill. So 20 mill would only contain 2.5g of silver nitrate and 1.3 mill of acetic acid. If the process starts to fail then renew your chemistry. Greenlaws process was a simplification and the evolution of a process , using the minimum of ingredients at a time when the practitioners of the 1850s were hell bent on making it as complicated as possible . This process is easy and reliable in all conditions. Perfect for the beginner.