If you ever tried to use classical manual focus lenses with a digital or analog SLR camera you might have recognized that problem: The standard focusing screens of modern auto focus SLR cameras are optimized for use with AF type lenses. Most of them, however, are lacking optical focusing aids (e.g. split/microprism screens) that makes it hard to visually judge sharpness.
However, precise and reliable focusing is required to fully utilize the capabilities of the Carl Zeiss SLR-lenses. These lenses can be attached to all relevant camera housings with EF-, F- and K-bayonet mount; ZF- and ZS-lenses additionally to other camera systems using an adapter.
Therefore, if manual focusing lenses are used on auto focus cameras, Carl Zeiss recommends giving particular attention to the focusing screen used.
In most of the Canon EOS, Nikon AF and Pentax AF cameras, whether digital or analog, electronic focus confirmation continues to be available even when using our ZE, ZF or ZK lenses. The camera confirms that the manual focus is correct by illuminating the focus confirmation light or the active AF point. In many of the Nikon models (e.g. the D700 and D3 series), additional support is provided by two arrows in the viewfinder which indicate the direction of rotation for the focus ring when performing fast manual focusing.
However, these electronic focusing aids only actually provide a relatively imprecise means of achieving high-precision manual focusing. The region shown as "in focus" when rotating the focus ring is generally quite large and is also dependent on the direction from which the subject is being brought into focus (i.e. whether you are coming from infinity or from the closest focus distance). We therefore recommend comprehensively testing the camera in combination with a manual lens in order to get a photographer's feel for the situations in which you can rely on the AF indicator. Especially when using fast lenses, it is advisable to take a bracketing series with a wide-open aperture and short shooting distances in order to achieve optimum results.
Quite a few digital and analog cameras are already well equipped. The standard focusing screens of the following camera models are well suited for manual focusing:
Nikon: D2 series, D3 series, F6
Canon: EOS 1/1D/1Ds series
For the camera models Canon EOS 1Ds MkIII, EOS 1D MkIII, EOS 1D, EOS 1DS, EOS 1DS MKII, EOS 1 MK II, EOS 1V, EOS 1, EOS 1N HS, EOS RS and EOS 3 we do recommend type EC-A (with micro prism ring) or EC-B (incl. split-image indicator) which are offered by the manufacturer and can also be purchased at specialty retailer stores.
For the Canon EOS 5D, for instance, the manufacturer offers a screen with improved manual focusing characteristics (Screen Type Ee-S) and also a third-party-manufacturer offers a focusing screen for this model at:
For many other popular auto focus SLRs, interchangeable focusing screens are offered by independent manufacturers. Such screens for current Nikon or Canon DSLR models are for instance available at: