Enlarging lenses do not have a helical focusing facility because focusing is performed with the enlarger’s bellows extension. If an enlarging lens is used as a taking lens, it is necessary to fit a focusing device. The Modular-Focus developed for this purpose has a stroke of 25 mm and offers high setting precision and stability to match our enlarging lenses’ high image quality. The straight-line guide guarantees that the lens does not rotate with the focusing ring. Once the aperture window display has been adjusted for best readability by rotating the Modular-Focus against the adapter, and once it has been subsequently fixed, then it will permanently keep its optimum position.
The Modular-Focus can be fitted to almost all 35 mm system cameras by using a T2 adapter with conventional connecting rings. For the use with cameras with M42 lens thread there is a M42 connection ring. Furthermore, the modular-Focus can also be fitted to professional CCD and video cameras with exchangeable lenses using the optional C mount connection.
For attaching the lens, adapters with M39 and M32.5 thread are available (see table). For lenses with illuminated f-number display there is a special adapter that blocks the entrance window for the light in order to avoid irritating stray light. Extension tubes with a length of 24.5 mm and 45 mm allow larger extensions for long focal lengths.