Archive
These are archive news and articles...
Rolling down the years
Roll film is today a non-topic - there's 120, and that's it, no further knowledge required. But at one time there existed a multitude of roll film formats, 26 distinct varieties according to one authority, which were culled mainly in the 1940's and 50's, and what is left can be counted on one hand.
But the whole roll system was a legacy left by Kodak, dating back to the dawn of consumer photography, and what we're left with is a mere appendix of what was on the market a century ago.
The first Kodak roll film camera was a 'back to base' model, taking 100 pictures on film which had to be factory loaded and exchanged, so there was no requirement to code the film inside it. The breakthrough was the daylight loading system of 1891, using film wound up with backing paper overprinted with frame numbers, exactly as used in remaining roll films still used today. There were only a few models of these earliest roll film Kodak cameras, and the films supplied to fit them had the cameras they were intended to fit printed on the cartons. As the camera market developed exponentially in the following few years some sort of syntax was required, as not all films for the same size pictures could be used interchangeably, and both image size and camera model had to be specified.
So straightforward 3 digit numbering was initiated, beginning with 101, which was allocated to the film used in the 1895 Kodak Bullet Camera. Numbers 106 through to 129 had been used up by 1913, after which time the system started to break down and haphazard logic was the order of the day. In 1916 a miniature box camera was introduced using unperforated 35mm roll film taken from cine stock and coded '35'. However the '135' code was given to perforated 35mm film when it eventually came out in cassettes in 1934. The idea of using the prefix number as indicating exposures was initiated in the 620 and 616 cameras of 1931, which employed a smaller diameter spool to allow the use of a smaller camera body. By the time the cameras came to market the number of exposures had been increased to 8, but the ?6? endures there to this day.
All coding, spool design and dimensions were initiated by Kodak, although there were one or two rather abortive attempts by other manufacturers to hijack the system for their own ends. The British ?Amalgamated Photographic Manufacturers? company came up with 'Rajar no. 6' film, a spool similar to 120 but with a protruding square drive slot, and this was of course designed to be the only spool to fit their own camera. It didn't take long for 120 adapters to be devised, and the format died.
The design of the spool at first was a wooden core fitted with crimped on metal flanges. Later the flanges were spot-welded onto a metal core, while modern spools are extruded plastic. Possibly the costs of changing the spool from metal to plastic was what dealt the death knell for most roll formats, which dropped away especially quickly through the 1940's to 1960's.
One or two of these long-gone roll film sizes have a certain resonance with today however. The '122' format, dropped in 1971 was postcard size, 3.25 x 5.5" - what a wonderful format for contact printing. In the present age, when Lomos and Holgas are being used for their novelty value, would there not be great interest in a modern budget priced super-size roll film camera? It wouldn't be impossible to recreate a format, and at the time of writing there are good supplies once again of Efke '127' the little brother of 120, giving a new lease of life to all those 'Baby Rollei' cameras out there, which should be used, not collected.
Web references:
→ http://en.wikipedia.org/wiki/Film_format
→ http://www.nwmangum.com/Kodak/FilmHist.html
you can download this article as PDF → PDF format (143kb)
Geva-rchaeology
Some packs of very old 'Gevaluxe' photographic paper came our way a while back, and we are finally beginning to test it. To re-cap, Gevaluxe was a most unusual printing paper, being a bromide paper with a very warm base, but the remarkable feature was the surface, which resembled velvet, and worked in the same way as velvet when illuminated. The shadows absorb the majority of light falling on them, resulting in a matt paper with the high brightness ratio found in a gloss paper. The amazing depth of black and good shadow separation made it the 'Stradivari' of papers, at it's best when used in low key portraits, where the slight loss of definition was usually an advantage. Mentioning Gevaluxe previously in the magazine, it was stated that this paper was discontinued in the 1960's - this was was well out of range, the paper commenced manufacture in the early 1930's and was discontinued in the 1950's, prior to the merger of Gevaert with Agfa. The packs we have here, then, are certainly at least 50 years old, and judging by the label design, and the fact that the labelling refers to 'Germany', rather than East and West Germany, appears likely to be be pre-war.
Opening the crypt
Opening the paper at last was approached with trepidation, could it be possible to get a print from a material as old as this? The packaging was certainly devised to protect a delicate material. Inside the outer light card envelope was black light-tight paper in several folds. This enclosed a red waxed paper inner barrier which in turn was folded around two pieced of card, and between these was the Gevaluxe paper, the emulsion of the top sheet being covered by a sheet of heavy barrier paper. A small black paper packet contained test strips, a thoughtful touch, as this was the most expensive photographic paper ever made, and there were only 5 sheets to a pack. The size of this particular packing was the continental size 18x24cm, slightly smaller than the UK & US 8x10" format. The developer for the first test was the new Ilford Warmtone, at the recommended dilution of 1+9. Initially the test strips supplied were checked for fog level, which was unuseably high. A 2% solution of benzotriazole was made up to add into the developer as a restrainer, and more tests were made adding successive 20ml quantities of this solution into the developer, checking more test strips until the fogging abated somewhat. At which point the full size sheets were unwrapped. The classic mistake was now made of trying to print on the barrier paper, and having finally figured that one out a test was at last made on a cut piece from the full size sheets. Astoundingly there was no problem with fog whatsoever, and the developer containing the benzotriazole was discarded and replaced with fresh unrestrained developer. It appears that the test strips had been contaminated by their envelope, while the full sheets with their excellent packing had survived half a century unscathed. The negative was low key and on 8x10? film, chosen on the basis that the paper was likely to have lost so much speed that plenty of light would be required. Once again a surprising find, the exposure was only six seconds when contacted on the enlarger baseboard, not far off the times used when contacting onto Multigrade.
...and for the next 50?
Finding it possible to print on this most ancient of printing papers has been a rewarding experience. Gevaluxe prints are astonishing, both in their tonal range and their unique tactile presence. Is it possible, now that the photographic art market is so established, that there will again be a potential for this type of paper? At any rate the remaining packs we have of Gevaluxe are back in cold storage and some is reserved for Ilford's tests, in the hope that there may one day be an 'Ilfoluxe'!
Zero Image Pinhole Cameras
Zero Image is a Hong Kong based company, producing a range of beautifully designed and finished pinhole cameras in a variety of formats, all of which we have in stock. The most eye catching design has to be the Zero 4x5 model (left). In the standard configuration this will deliver an ultra-wide image, and even though the body depth is only 2 cm, the 5x4? film is covered right to the corners, indicating excellent pinhole construction.
A principal feature of the 5x4" design is the extension frames which can be used to increase the effective ?focal length? of the camera, and these simply nest into place and are secured with rubber bands, as is the dark slide (not included). All the cameras are made with exceptional attention to detail in hard woods, the 5x4? model being teak. All are gloss varnished with brass fittings, and supplied with a certificate showing edition number. The basic 120 roll film model is the Zero 2000, while the 6x9 Multiformat offers 4 formats from 6x4.5cm through to 6x9cm. The 35mm camera is also dual format, either standard 23x35mm, or panoramic 23x45mm.
All cameras are supplied with an ingenious exposure dial, which can be used to calculate exposure times using a reading from an exposure meter or camera readout. Cameras are supplied with both pinhole and zone plate. All cameras are fitted with brass tripod bushes, on both elevations in the 4x5? camera. Full technical details on our website, and examples of images from all cameras.
Prices
Pinhole cameras should be affordable, and we are offering a very low price on our initial shipments, although this is likely to rise in the new year. All prices include VAT at 17.5%.
- Zero 4x5 Multi Format System:
- 25B (Basic Camera) → £90.50
- 50B (inc 1 extension) → £135.72
- 75B (inc 2 extensions) → £180.95
- Toyo Double Darkslide 4x5" → £23.50
- Zero 2000 (120 Film) → £90.50
- Zero 6x9 MF → £155.00
- Zero 135 → £90.50
Carriage on all cameras is £6.00 per shipment but free to most UK addresses if the total order value is over £100.
Emulsion Archive
It is a sobering thought that athough photography using emulsions has only been with us since 1877, the whole technology is in the process of being closed off, having been replaced in the mass photographic market with digital techniques. Demand for traditional film and paper products has been quickly falling away, evident in the loss of enormous diversity in emulsioned products, for example lithographic films and papers, only ten or so years ago the basis for the graphic arts industry, now almost completely vanished.
Consider also that photographic material manufacturing has since its inception operated on the principle of mutual secrecy - small variations in emulsion recipes and manufacturing techniques control the enormous range of behaviour possible within emulsioned film and paper, and this knowledge, gained at great time and expense in research is locked within the archives of the manufacturers, and will not emerge. As photographic chemists and technicians retire and eventually fall off the perch much additional knowledge is also lost, practical data not recorded which has been an integral and essential part of the manufacturing process.
At Silverprint we have always had a certain fascination with emulsion techniques at a basic level, and in 1995 threw a lot of effort into producing the book 'Silver Gelatin', which has remained the only book dealing with self-coated emulsion. And now it seems it may be the time to rally the troops again.
Consequently we are kicking off something which may or may not bear fruit, but certainly seems worth testing, an archive of photo emulsion data and techniques at all levels, as an integral part of this website. Initially we are putting up a number of books in PDF format, all now out of copyright including the highly comprehensive book by Wall. The intention is to provoke interest and discussion, and hopefully bring in contributions from what's left of the industry itself. There is a lot of material lined up to include at the outset, but for starters the first scanned-in text is the dry-plate section from 'Wilson's Quarter Century in Photography', written in 1887 just as modern emulsions were arriving, and including contributory chapters from luminaries of the time such as William Abney and even George Eastman, amongst 300 others.
The APUG site has been running a number of emulsion oriented threads starting in 2006.
More about emulsion archive:
Rollei Box Pinhole Coversion
The inspirational pinhole issue in 'Black & White Photography' magazine last month gave rise to a little bit of lateral thought, and suggested a new use for the 'Rollei' wooden film boxes, supplied with 10 packs of 35mm, and 12 packs of 120 Rollei films. Although making excellent pencil cases, there surely ought to be ways of recycling them into photographic channels, so here is one option, an ultra wide panoramic pinhole conversion requiring very little work to commission.
The interior of the box was painted in matt black, the front drilled out quite large (not large enough on the Mk 1), and black photo tape used to wrap around the lid joint after loading. As luck has it, 5x7" paper or film if cut lengthways is virtually a perfect fit - magic tape was used on to tack the material into the box, but some guide channels fastened to the back would be a more permanent arrangement. The shutter was black photo paper bag plastic taped on the front, removed and replaced in the fashion of using a lens cap for the purpose. The camera was fastened onto a tripod with a strong elastic band; the first test used HP5 film, exposure time 5 seconds in bright sunlight.
You can download this article as PDF → PDF format (161kb)
Not Fade Away...
Silver photographic images, even when well processed will always be prone to degradation through the ravages of time. The picture above, printed on 'Barnet' bromide paper in 1905 shows the tarnishing typical of a print of this age - still a good density range, but a proportion of the image silver has migrated to the surface of the print and plated out as a reflective silver film.
Similar effects can happen more quickly and dramatically - twice in the last year we have had newly produced prints returned supposedly with faults, loss of density in the shadows and little gold spots in the mid to low densities. In both cases it turned out the prints had been framed using low grade hardboard with no intermediary vapour barrier layer between the back of the print and the board. Similar rapid attack can happen in a display environment where there has been fresh painting, and higher than normal heat, light and moisture will always accelerate this oxidation process.
From the earliest days image fading was a known problem, and an immediate fix was toning, often with gold salts, but as papers became more robust, sulphide (sepia) toning became prevalent. In the 20'th century selenium toner arrived on the scene, and being espoused by luminaries such as Ansel Adams, came to be regarded as the ultimate finishing treatment for print permanence. This was because selenium did not cause major colour shifts with most papers when used diluted, and as well as improving permanence tended to increase tonal range in a subtle way, and generally enhance the final print. Selenium toner was also widely adopted as a permanising treatment for film records such as microfilm and astronomical plates.
The Strange Case of the Temperamental Toner
Lee, Wood, and Drago published a paper in 1984 dealing with the stability properties of a variety of toned images and found selenium acted very well as a protective treatment However when the Image Permanence Institute at Rochester Institute of Technology delved further into the action of selenium they found that although selenium worked well for high density areas (shadows), it did not convert the mid-tones and highlights that well, contrary to general opinion. When this was referred back to Kodak, they went back in their records for formulations and chemical sources. Prints produced by practical users in the field had highly stable prints, but this stability was not supported by lab tests, which showed a much lower level of resistance to oxidants. It was some time before they realised that there was a difference in the make-up of the chemistry; the consumers were using selenium toners made from GPR chemicals (general purpose reagents) while lab experiments were being done using analytical reagent grade chemicals (very high purity.) It turned out that sodium thiocyanate in the consumer toner was made from practical grade chemicals contaminated with a number of active sulphur compounds, while the high purity analytical grade chemicals contained no sulphur. Consequently, the action of selenium as a permanising agent was revealed to have been seriously over-rated, and those of sulphiding agents need to be re-assessed. This is indeed taking place, and most institutions involved in photographic conservation are now recommending some form of polysulphide toning rather than selenium. Potassium and sodium polysulphides are not the most pleasant of chemicals in the raw state, corrosive and smelly and we do not normally stock or sell them. Fortunately there is a manufactured article, freshly restored to the marketplace.
Polysulphide Toner for Permanence
Viradon is primarily sold as a brown toner, and when almost 100% of the silver has been converted to silver sulphide a warm brown image will result - no bleaching is required. It is particularly good for warm tones in combination with Ilford Warmtone Multigrade. Partial convertion will show little or no colour change, although the permanising effect is still active, and a strange property is that conversion is speeded up as dilution is increased, and the toner becomes more exhausted. Consequently, this type of highly active polysulphide toner can give complete protection even when used at 1+200 dilution. One authority recommends a time of 1 minute at a 1+50 dilution, which will convert approximately 75% of the silver to silver sulphide, leaving no colour change.
Although there has been much research, and the evidence for the effectiveness of polysulphide is beyond doubt, it remains curiously unknown to the wider photographic public. There is much data on the web, and we will put the main references into a web page linked from the Viradon entry in our website. The "NEW" bit refers to the fact that the previous version contained selenium, whereas this is now purely polysulphide based. The downside- evolves hydrogen sulphide (bad eggs) which is not good for film and paper, although when used at high dilutions this should not cause a problem. The price, a mere £10.76 for 125ml. And remember you read it here first, folks.
The Goldfinger Story
The current schism in the traditional photographic world due to the digital onslaught may seem as if it has no precedent, but to those of us who were printing in the 1970?s it is revisiting old ground. At that time traditional materials were under great threat - resin coated paper technology had arrived quickly, and by the mid '70's RC paper was viewed by many users and suppliers as the logical replacement for the ?old fashioned? fibre-base paper. In 1974 Agfa took the extreme step of discontinuing all black and white materials in the UK, and it seemed the door was closing.
Enter an unlikely set of Don Quixote style characters to champion the cause for the traditional. Paul Hill, one of the prime movers and shakers at the forefront of UK photography, was at the time making many connections through his intense series of workshops at 'The Photographers Place' in Derbyshire. One of the early workshop participants was Peter Goldfield, a North London based pharmacist, who had been bitten by the bug badly. Possession of a existing retail front offered possibilities, so Paul and Peter worked on the idea of re-importing Agfa paper into the UK by the back door. Peter enlisted the help of Martin Reed (that's me), and the first shipment arrived from a Hamburg based wholesaler in November 1977. Most new retail businesses experience that wonderful, terrifying feeling of sitting in a barren room with a pile of newly acquired stock, and wondering how on earth to sell it. In our case we had a list to start with of about thirty people throughout the UK who had expressed interest in getting supplies. We stuck pins of their locations in a map of the UK, in the ?operations room? above the shop, and wondered if there would be more than thirty, or was that it? We thought maybe some real prints as samples would help, and sacrificed some stock to make a stack of 5x7" prints on Record Rapid and Brovira.
We also started putting together a little book to get the message over, calling it "The Goldfinger Craftbook for Creative Photography" and which still changes hands for a few pence at collectors fairs. Photographers and printers who had been brought up on a basic diet suddenly came face to face with the richness possible from the fantastic range of materials Agfa were still producing in unadulterated form. We started to bring in Kodak selenium toner, then unknown in the UK, and explore new territory in archival washing and drying, as well as the problems of archival storage. Nick Hayden, freelance photographer and teacher became part of the team, joined part time by his college friend Richard Ball. Peter Benson came in from the photo. lab industry, joined by young enthusiast Ben Haxworth. A small gallery was established. To cut a long story short, it was all successful. So successful that in 1981 Agfa UK decided to themselves take over distribution of black and white into the UK. Sudden removal of carpets. Que sera sera.
What became of the Brovira Boys? Peter Goldfield followed his artistic star and set up 'Photographers at Duckspool' in 1985, which for many years worked in tandem with 'The Photographers Place', and is still operating now, although Peter is starting to take life a bit easier. Take a look at what he is up to at www.duckspool.com Nick Hayden died in unfortunate circumstances in the mid-90's. Richard Ball and Peter Benson became commercial photographers. I set up Silverprint in 1984, initially majoring in Oriental Seagull paper. In trying to broaden the supplier base we started stocking an increasingly wide range of materials, and now that traditional photography and printing is a niche interest this approach still seems to be valid.Number 329 Muswell Hill Broadway became, and is still, a hairdressers called 'Goldilocks' (no connection). For those that want an even closer inspection of the gravel on memory lane try the downloadable PDF copy of the 'Goldfinger Craftbook' below.
Schulze
In 1727, Johann Heinrich Schulzc demonstrated that some chemicals are light sensitive. Using a flask containing chalk suspended in silver nitrate, he showed that when exposed to light the mixture turned from white to purple.
"Considering that knowledge of the chemical as well as the optical principles of photography was fairly widespread following Schulzes' experiment- which found its way not only into serious scientific treatises but also into popular books of amusing parlour tricks - the circumstance that photography was not invented earlier remains me greatest mystery in its history." (Helmut and Alison Gernsheim).
"Cameras", in the form of the camera obscura, had been around for several centuries, used as a drawing tool by artists and scientists. Leases had been fitted for a brighter and sharper image from about the middle of the 16th century, and by the 18th century it was being commonly used in a portable form, with a mirror behind the lens throwing the image up onto a shaded ground glass screen.
The development of the medium to record this image did indeed get off to a slow start, and no one individual technological breakthrough helped it. Of the main contributors none performed totally original work, since they just combined principles that had been known for some time. None was aware of the others work, apart from Daguerre and Niepce, who collaborated, and none could have claimed to be first past the post, since several quite distinct forms of imaging were produced, with different uses.
Wedgewood
Thomas Wedgewood, son of Josiah Wedgewood the potter, examined this chemical effect in about 1800, probably inspired by using the camera obscura to trace pottery designs. His starting point was the effect discovered by Schulze.
Wedgewoods' research was published by Humphrey Davey in 1809:
"White paper, or white leather, moistened with a solution of nitrate of silver, undergoes no change when kept in a dark place; but on being exposed to the day light, it speedily changes colour, and after passing through different shades of gray and brown, becomes at length nearly black... outlines and shades of paintings on glass may be copied, or profiles of figures procured, by the agency of light. When a white surface, covered with a solution of nitrate of silver, is placed behind a painting on glass exposed to the solar light, the rays transmitted through the differently painted surfaces produce distinct tints of brown or black, sensibly differing in intensity according to the shades of tile picture, and where the light is unaltered, the colour of the nitrate becomes deepest.
..."After the colour has been once fixed upon the leather or paper, it cannot be removed by the application of water, or water and soap, and it is in high degree permanent. The copy of a painting, or the profile, immediately after being taken, must be kept in an obscure place. It may indeed be examined in the shade, but in this case, the exposure should be only for a few minutes; by the light of candles or lamps, as commonly employed, it is not sensibly affected.
..."the images formed by means of a camera obscura, have been found to be too faint to produce, in any moderate time, an effect upon the nitrate of silver. To copy these images, was the first object of Mr Wedgewood in his researches on the subject-Nothing but a method of preventing the unshaded parts of the delineation from being coloured by exposure to the day is wanting, to render the process as useful as it is elegant".
This was published posthumously - Wedgewood had died in 1805, very close to achieving a workable process.
Niepce - The Heliograph
A French amateur scientist, inventor and artist, Niepce investigated the silver effect in 1816, an an attempt to transfer images directly onto lithographic plates and stone. Like Wedgewood he sensitised paper with silver salts, but ran into the same problem of being unable to fix them. Discarding silver, he came up with something somewhat related to the later Bromoil and Gum-bichromate printing processes. He used plates coated with a varnish which hardened with the action of light, and which when 'developed' by washing off the plate in a suitable solvent showed a positive image. In about 1826 one of these "heliographs" was produced with an 8 hour exposure in a camera obscura. It is still in existence in the Gernsheim collection - the oldest surviving photograph made with a camera obscura.
Daguerre - The Daguerrotype
Niepces heliograph process was a blind alley so he collaborated with another French inventor, Daguerre, to evolve a more practical process. Daguerres' background was infact more theatrically orientated - he was the originator of the Diorama, a theatrical illusion using painted transparencies which were animated with changes of light direction, intensity and colour. To assist in the drawing of these he used a camera obscura, which presumably motivated him to attempt to record these images. Niepce and Daguerre shared a common optical equipment supplier, who put them in touch with each other, and they forged an agreement in 1829 to exchange information and work together towards a workable process. Niepce died in 1833 - his work was continued by his son, but it was Daguerre who perfected a method.
Daguerre used a polished silver plate, which was sensitised by exposure to iodine vapour in a closed box. No visible image appeared even with lengthy exposure,, but Daguerre used a developer (the vapour from heated mercury) to produce a visible image. Moreover, the process could be stabilised-processing in a hot solution of common salt removed unused silver iodide.
Later additions to the process added bromine to the iodine vapour to improve exposure sensitivity, and a final gold salt bath to improve permanence. The highlights of the image consisted of the silver/mercury amalgam - the shadows were the polished silver. It was actually a very thin negative image, but showed positive when the plate was carefully tilted to reflect a dark field (a similar effect can be reproduced with a very thin filrn negative); by its nature, a Daguerreotype was always laterally reversed unless the photograph was made through a mirror. The finished plate was highly susceptible to tarnishing and it was essential for it to be sealed in a small viewing case immediately after processing. Each plate was unique and copies could not be made easily; the complexity of the process destined it to early obsolescence. However the announcement of Daguerres' process forced the early publication of another process that was to prove more enduring.
Fox Talbot - The Calotype
Termed 'Photogenic Drawings', by him, and now generally known as salt printing. Good quality writing paper was saturated in a bath of sodium chloride (common salt), then bathed with silver nitrate solution, giving a very slow sensitive paper that could be used to make silhouettes by exposing to sunlight, me material was too slow to be used in any form of camera. Fixing did not exist, the paper was just desensitised by putting it through a further salt bath (which produced a purple tone in the image) and consequently prints were not very stable, although original prints made at the time do still exist. The process is easy to repeat oneself.
The Salted Paper Process, 'Calotype', as named by Fox Talbot, was tile first real photographic process and introduced the major step of utilising a development stage- Salted paper was prepared as for photogenic drawings, and could be used in a camera if it was processed through a solution of pyrogallic acid.
At about the same time it became possible to fix the image, using the same agent as now, sodium thiosulphate, (or 'HYPOposulphite' as it was then called, which will probably stick for ever more). The resulting negative print was waxed to improve its light transmission, and then contact printed onto a piece of the same material. The image was very warm in colour, being formed of very finely divided silver particles.
The process was fine-tuned over the next couple of decades; it was found that different types of base paper affected the image colour and sensitivity, gelatin sizing giving the reddest tones, while starch sizing gave a browner colour. A major improvement was the introduction of a combined salting and sizing solution which was brushed onto one side of the paper, rather than saturating the whole sheet. This method of coating improved the brilliance of the negative by concentrating the sensitive sails at the surface of the paper, but the image quality was still influenced by me fibrous make-up of the paper, some prints showed mottling and low definition.
Wet-Plate
The next advance in me making of the negative was to be able to produce it on a glass plate; its flatness and transparency making it ideal The only way this could be done was to find a suitable binder to hold the sensitive salts, as a substitute for the fibres of the paper negative; this was found in collodian, a syrupy substance made by dissolving gun-cotton (cellulose nitrate) in ether.
Potassium iodide was dissolved in the collodion and poured onto a glass plate tilting it to cover the plate evenly. As the ether evaporated me collodion became more viscous, and when it reached a suitable consistency it was sensitised by being put into a silver nitrate bath. The plate had to be exposed immediately, while still wet, as there was a dramatic loss in speed as it dried. After exposure the image was given a conventional develop/wash/fix cycle.