Agfa Agfachrome
Agfachrome was the brand name for slide films from the German photo article manufacturer Agfa .
Until the merger with the Belgian Gevaert to form Agfa-Gevaert, these positive films were sold under the name Agfacolor , the same name as the color negative films .
Agfachrome CT 18
The Agfachrome CT 18 (Color Daylight 18 ° DIN ) was considered by many amateur photographers in Germany from the late 1960s until its discontinuation in 1985 as the standard material for slide photography. The film with a sensitivity of ISO 50/18 ° was known for its warm, pleasant colors, which was especially true for the reproduction of skin tones, at the expense of color accuracy. The sharpness of the slides was good, the graininess clear.
The film is not particularly stable over the long term. Despite good storage, the slides show very clear color shifts towards red after a few decades at the latest. Kodak Ektachrome of the same age shows a significantly lower color shift (towards blue).
When scanning with film scanners, which remove dust and scratches via an infrared scan, the CT 18 (similar to the Kodak Kodachrome, but not as pronounced) shows the tendency to block infrared. This can cause the infrared dust and scratch removal process to malfunction.
Agfachrome CT 18 was developed in Agfa's own AP-41 process and was therefore incompatible with the later most common slide film processing process, the E-6 process from Kodak . In 1984 Agfa finally switched its slide films to the E6 process; in the 1990s, development in the AP-41 process was stopped almost everywhere. Today (2013) only a few specialized companies worldwide offer the development.
In the GDR , during the division of Germany, a very similar film was made by ORWO - a former Agfa factory - as Orwochrom UT 18 (reversal film daylight 18 ° DIN) up to the 1990s. ORWO recorded a compatible development process in processing instruction 9165 .
Modern agfachrome films
After the slide films were converted to the E-6 process developed by Kodak in 1984, the brand name Agfachrome was retained. These more modern films featured a more natural color scheme and finer grain. However, film connoisseurs complained that they lacked the typical coloring and the accentuated grain of the CT-18 slides.
Agfachrome RSX
Agfachrome RSX was a professional-grade slide film that was sold from the late 1980s until the Agfa photography business was closed. After that, until 2014 only the variant with 200ASA as "Aviphot Chrome 200 PE1" for aerial photos was still produced in the Belgian Agfa factory and z. B. from Hans O. Mahn & CO. KG under the name Rollei Digibase CR . Remaining stocks are still available from some providers now (July 2015).
Resolving power
The graininess is reported as an RMS value . The resolving power was measured at various object contrasts (1.6: 1 and 1000: 1) and is given in lines per millimeter.
| Film type | Graininess ( RMS ) | Resolving power in L / mm with object contrast | |
|---|---|---|---|
| 1.6: 1 | 1000: 1 | ||
| Agfachrome RS 50 Plus | 10 | - | - |
| Agfachrome RSX II 50 | 10 | 55 | 125 |
| Agfachrome RSX II 100 | 10 | 50 | 125 |
| Agfachrome RSX II 200 | 12 | 50 | 110 |
| Agfachrome 1000 RS | 26th | - | - |
Individual evidence
- ↑ [1]
- ↑ [2]
- ↑ Information according to the data sheets of the manufacturer and the University of Basel ( Memento of March 25, 2006 in the Internet Archive ) (PDF).