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Mechanische camera's
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Mechanische camera's

Spur Ultraspeed Vario

When Schain recently introduced a new two-bath developer “Ultraspeed Vario” that has been characterized as a “developer system” I immediately became curious. The system claims to offer push- and pull capabilities for all BW films on the market with some exceptional characteristics. Push development (setting a higher ISO value (underexposure) and extended development) results in grainy negatives, high contrast and reduced shadow definition. Pull development (setting a lower ISO value (overexposure) and reduced development) results in low contrast and flat negatives. Contrast management is however the core of the Zone system in which the contrast of the scene determines the choice of exposure and development. A higher practical sensitivity is always an advantage when using slow films. Even high-speed Leica lenses can benefit from higher practical speeds because the photographer can use a higher shutter speed (always nice to have) and a higher contrast increases the edge sharpness. 
Most developers that claim a speed improvement only increase the steepness of the curve around the mid-grey area and rapidly loose shadow detail as the inherent speed of the emulsion is not changed and under exposure does naturally diminish shadow detail. The high speeds sometimes claimed for super-developers does not deliver the goods. 
The Spur Ultraspeed system seems to have squared the circle. A higher ISO value (read underexposure by one stop) and still a good definition in the deep shadows is a goal that everybody will welcome.
I selected the reference film in the ISO100 class (Kodak TMX100) and also the classic Ilford film FP4+. This is also a comparison between classical grain emulsion and modern T-grain emulsions. Many persons prefer the FP4+ because of its sharpness (grain impression) and its excellent tonality. This emulsion can also be fine tuned more precisely in its tonal scale. It is a perfect choice for the application of Zone System techniques. There has been a long dispute between the new and old schools of silver-halide technology. The shell-core and tablet shapes allow for a lower silver content and a reduced grain impression. The negatives are in general less dense when developed properly and this has a consequence for the dark room techniques.
The classical grain shapes and structures as used in the FP4+ and others like Adox have a higher silver content, a denser negative and a finer scale of grey tones.
Heidrich and Schain, the driving forces behind the Spur chemicals are a most innovative team  that tries to find new ways for an old technology and tries to bring new insights to solve old problems. With Acurol they produced an up-to-date developer concept that pairs flexibility of use to the methods of the Zone System in a simplified, but effective way.
Push technology in the Zone System tries to improve contrast in low contrast scenes and to limit the loss of shadow detail. And push technology has a cult status in some circles where one tries to boost the ISO values to high numbers. A gritty picture with strong black-white contrasts is the result, quite popular in the 1960s. 
The new Ultraspeed Vario is a two-bath developer that is easy to use. The developer times for both developers can be varied to achieve different ISO speeds, or to be quite precise a different Exposure Index. 
I exposed both films at double the official ISO speed (250 in the case of the Ilford film and 200 in the case of the Kodak film). 
The Fotowand grey card was used and the exposure was measured with the classical Gossen Mastersix. Development was according the instructions and the measurement of the negatives was done with the Heiland densitometer. The results are in the graph below.

Both films show comparable characteristics as fas as the density curve is studied. The important zones from II to VII are very well recorded with printable densities on Grade 2 and excellent contrast. Zone I (the official speed point) is a bit low in density, suggesting that the best exposure index would be +2/3 stop and not a full stop. But this speed gain is welcome and in any case you have a significant under exposure latitude. The highlights might be less dense, but that is easy to correct by adjusting the development time of the second part. The great and positive surprise is the fact that this speed gain is achieved with only the smallest increase in grain and no loss of tonality. Comparing both films it can be noted that the Kodak has the finest grain, but the grain of the Ilford film, although just visible at 10 times enlargement, gives a visually pleasing impression.
The Ultraspeed can be used with every film and operates within the range of pull (N-4) to push (N+2). The normal development (N) is also available. The Spur range of developers now covers the high definition side (Modular UR) and the high speed side (with Kodak TMX 400 an exposure index of 800 can be safely used) within the classical ISO range of ISO 25 to ISO 800. Photographers with digital cameras will laugh about these values (used as they are to speeds of 2000 and much higher), but two remarks. Technical the silver halide emulsions have a quantum efficiency of at best 10% and CMOS sensors have a QE of more than 60% allowing for a much more efficient speed gain.Philosophically spoken the silver halide films operate within the time-honored range with which all the great photographers worked and produced the best results.