The modern slow speed silver halide film: Adox and Spur
Slow food culture It started in Tuscany, Italy about ten years ago. A group of people wanted to restore some of the flavour and style of slow life, a tradition that places value on a slower rhythm in life. The idea is that it takes time to prepare food from the natural ingredients in such a way that the taste is maximized and as a result you need time to experience the quality of the food. This style of life helps you to become aware of the quality of your life and the decisions you make. The slowlife movement is now a world wide phenomenon and its approach and philosophy matches quite well with that special type of photography, that was once the only way of recording images by opto-mechanical means: the black and white silver halide photography. If you look at the sparse headlines that mention new products in silver halide photography we see that the progress is concentrated in the very highspeed colour neg films of ISO 800 and above. In this area the film has definite advantages compared to solid state capture as the fine grain does not produce such a high level of noise as does the sensor composed of the array of pixels. Black and white photography seems to be relatively stable if we may believe Ilford and some others. It will stay a niche market, but recently some new or revamped products draw attention to the pictorial and recording qualities of the slow speed film emulsions. The main product in today's black and white world is of course the Kodak Tri-X film. But at the other end of the spectrum we find the very slow speed films that offer characteristics that cannot be ignored. It is best to cover the whole imaging chain whwn using black and white film from developing in chemicals to the final chemical print in the darkroom. Here one experiences quite consciously the choices and the qualities of the silver halide world. The very thin emulsions are unforgiving in the exposure area and focusing and framing must be done with consideration. You do not take that many pictures as developing many rolls of film is time consuming. Slow photography we may call this approach as a reference to the slow life movement. There is a widespread misunderstanding that slow speed films must be used on a tripod. The document films that I am introducing here have a real speed of about ISO 10 to ISO 25 (nominally they are all ISO25). The sunny 16 rule will tell you that in normal daylight (why do 35mm photographers always insist that near darkness is the only good ambient environment for taking photographs?) you can use a speed/aperture combination of 1/250 at f/4 or even a 1/1000 at f/2.8. With the current crop of excellent high speed lenses (examples the Summilux-M 1.4/50 asph, the Sonnar-ZM 1.5/50mm, a spade of f/2 designs from 35 to 90mm and a fistful of 2.8 lenses from 21 to 35mm) the slow speed films can be used in a variety of light conditions and situations. And the image quality is better that what you get with solid state technology, at least up to 13 MP sensors. Current document films The document films, of which the Kodak Techpan was one of the main products, have a mixed reputation. They are certainly grain free, but the steep CI value demands special developers to get a decent curve suited for pictorial use. High resolving power is the second property that attracts users. But one does not always need that level of resolution and sometimes the claims are greatly exaggerated. The disaster of the Gigabit film is still fresh in memory. The Copex Rapid micro film from Agfa-Gevaert is just not suitable for pictorial use and the high resolving power is only useable when the special characteristics of the emulsion are preserved. A better alternative is the Kodak Imagelink HQ, developed in Schain chemicals, but the grain is not so superfine as you would prefer. Now a third film is on the market. Adox CMS 20. This film has the finest grain that I have seen over a long period of years. Even under the microscope at 100x magnification the grain is hardly visible. One needs to use a special developer, the Adotech 50, also available from Adox. But there are many pota type developers on the market that can be used. Originally Dr. Schleussner Company manufactured Adox films in Germany. For many years the films were unsurpassed for its resolving power and sharpness impression due to the acutance effects. But Kodak and Ilford introduced improved versions of their classical films and after Dupont acquired the Adox facilities, it was very quiet around Adox. Later the marque was sold to a company in the Eastern European area and EFKE became the label. This company used the original formula of the classical Adox films. I tested these films and them very good, but not so outstanding in comparison to the normal ISO100 films from Kodak and Ilford, that they could become the standard films to be used. Recently Fotoimpex in Germany has introduced a new series of Adox films of which the document film CMS 20 is quite interesting. The base is crystal clear and well suited to scanning if you do not want to work in the darkroom. First the workflow: the useable speed value is ISO16, which delivers well exposed negatives with excellent tonality and normal density. Of course the inherently steep characteristic curve limits the highlight densities and the workable subject contrast range is narrower than what you get from normal films. But that is one of the charming aspects of working with these films: you need to examine the scene, take exposure readings and make decisions. The Adotech developer is free from hydroquinone and therefore does not spoil the environment. With hydroquinone-free fixer from Amaloco the darkroom is quite healthy nowadays. Developing time is 5 minutes, stop bath 15 seconds, fixing time is one minute and washing with the Ilford method takes another two minutes. Then the film is ready to dry. The dense highlights are more related to the limitations of the scanner than to the capabilities of the film. In the darkroom you can handle the densities a bit better. It is wise as always to do some experimenting yourself. The great surprise! The Adox CMS film has a superb level of resolution. In combination with the very fine grain the images are outstandingly good. As a comparison I used the Maco/Rollei Ortho 25, a film I will discuss below. I made some comparison shots at normal subject distances with the Leica MP and Apo-Summicron-M 2/75mm ASPH at f/8. The overall picture shows the total negative area and the crops show the selection of the eye. One can see that the Adox has finr grain and somewhat better resolving power and sharpness impression.
Adox: then Rollei At this level of magnification one cannot see the claimed 800 l/mm. Now I am very sceptical about these high numbers as it is impossible to check these in pictorial photography. This picture however does not show the possible potential of the film. So I made another series of pictures, now from a scene at infinity and with the Elmarit-M 2.8/24mm ASPH and as usual tripod based. This lens at f5.6 is diffraction limited and has a measured resolution of more than 200 lp/mm (400 l/mm). The overall picture shows the total scene and you can see the row of houses at the horizon. The level of (negative) magnification is about 1:10.000(!) at this distance. The two sectional enlargements show the image quality of the Ortho 25 and the CMS 20. Again the CMS is the winner. Here we must state that the quality of the Nikon scan (at 4000 dpi) is not good enough to show the level of detail that is being resolved. The houses have small balconies before the windows and in the scene, made with the Adox film you can just see a faint representation of the balcony structures. Left: the landscape scene. The row of houses is just visible in the middle. Right above: Adox, below: Rollei
Under the microscope at a magnification of 100x, you see very clearly the structures of the balcony. Picture left. I made a picture with the EOS 5D with the lens set to 105mm to show you the structural details. This detail is not visible in the scan, but it is visible in (chemical) print and under the microscope. The comparison picture with the Canon at 24mm gives the indication that the silver halide recording capability at ISO16 exceeds that of the solid-state imagery. But that Canon shot was made at ISO400! The same shots at ISO 50 do not improve the resolution by the way that much. Here we have a film that gives better definition that we are used to in digital imagery. And this film does allow the full potential of the Leica lenses to be exploited. It is difficult to assign a quantitative value to the perceived resolution. But it is certainly way above 100 lp/mm and I might be mistaken but 150 lp/mm are an acceptable value. I will do more scientific measurements, but for now I must say that the quality of this film is amazingly good, Everyone serious about silver halide imagery should try this film, especially if you belong to the crowd of high definition aficionados. SPUR products The Adotech developer, by the way, is a formula developed by the SPUR team and is marketed under the name of SPUR Nanospeed UR. The Adox film is also available from SPUR under the name of SPUR Orthopan UR. Rollei ORTHO 25 The film strip reads ' made in Germany' so the idea could be that this film is the derivative of the famous Agfa Ortho 25 film. Once in a long forgotten period the Ortho 25 was the film par excellence for resolution tests. But there is another argument to use this film. The spectral response is such that yellow, blue and green are excellently differentiated, but red will be black and orange a dark grey. If you wish to take pictures as the founding fathers of photography did, the orthochromatic film is the one to use. The Rollei Ortho 25 has very fine grain, excellent sharpness and a tonal rendition that is quite interesting. When you use a pure yellow filter the tonal rendition is quite pleasing. The definition of the Rollei film is excellent and the film should be used more frequently when you wish to create a nostalgic effect. With the Leica camera and this film you are back into the past. The film can be developed in normal developers and in document developers. Maco supplies the Docufine LC, a receipt of Udo Raffay. This person is one of the more important chemical wizards who designed the best series of developers. Others in this group are Geoffrey Crawley with the FX series and Jaap van Beugen with the AM series of developers. Also the Spur team, headed by Heribert Schain, creates amazingly good developer formulas. Upshot The Ortho film offers excellent capabilities, above the normal ISO50 to 100 speed films and has interesting tonal qualities. The sharpness and definition are on a very high level. Low speed films are a way of life and the Adox CMS 20 is really a must when you wish to explore this route. Comparing the silver halide and the solid-state images we can see the main difference: not only has the film based picture a higher level of definition, there is also a philosophical difference. Film is a soft medium where digital imagery is more like television: the gradation of tonal differences is more step like and less smooth as with film and the textural representation is more etchy in the case of digital imagery. The smoothness and definition of the silver halide capture are very impressive and better than what you get with solid-state recording, at least up to the sensors with 16 Mb pixel size.. The choice is yours!
