The technical German term for a focussing screen is a “Bildfeldlinse”, which in translation is an “image field lens”.  This is of course correct, as the focussing screen is a condenser lens.  However, one should not imagine a complex lens such as the objective lenses fitted to cameras.  Its purpose is to provide a focussing surface for the image that is projected through the camera lens and the mirror.

Seven different focussing screens were produced by Pentacon for the Pentacon Six (TL).  What were the differences between them and what type of photography was each screen intended for?  Here are the answers.  In the interests of people who either are German speakers or who may wish to buy a focussing screen from a German vendor, I am including on this page the German titles for these screens and German descriptions of them, where available.
 
 

Introduction to the focussing screens from a German-language brochure „Spezialbildfeldlinsen sind für die Zwecke der Lupen-Mikro oder Astroaufnahmnen, für die spektroskopische und endoskopische Fotografie mit Klarfeld oder unmattiert erhältlich, damit das Scharfeinstellen mit größter Genauigkeit direkt nach dem hellen Luftbild vorgenommen werden kann. Ein Strichkreuz oder eine 5-Millimeter-Teilung oder ein Liniennetz mit Quadraten 10mm × 10mm für die winkelgetreue Ausrichtung der Kamera (Reproduktionen) und für das schnelle visuelle Ermitteln des Abbildungsmaßstabes bei Nah-, Lupen- und Mikroaufnahmen.“ (von „Pentacon Zubehör für Spiegelreflexkameras“ 1975)

My English translation “Special image field lenses are available for the purposes of macro, micro or astronomical photography, for spectroscopic and endoscopic photography with a clear field or clear glass, so that focussing can be undertaken with greatest accuracy directly on the bright aerial image. A hairline cross or a 5 millimeter division or a grid with 10mm × 10mm squares for the setting up of the camera at the correct angle (Reproduction) and for the speedy visual determination of the image scale in close-up, macro and micro photography.”   –  From the 1975 German-language publication „Pentacon Zubehör für Spiegelreflexkameras“ (“Pentacon Accessories for Single Lens Reflex Cameras”).

1) Standard groundglass screen
 

The standard screen with its retaining wire, screws and clips [stdscrn03.jpg]

English description (from 1974 English catalogue) Standard screen supplied with camera (Part Number 207260)  Intended use: “the simple fully ground-glass image field lens”. Deutsch (von „Pentacon Zubehör für Spiegelreflexkameras“ 1975) Bildfeldlinse, vollmattiert (Sach-Nr. 207260) Vergesehene Benutzung: (vom Prospekt „Pentacon Zubehör für Spiegelreflexkameras“ 1975)  „Der einfache vollmattierte Bildfeldlinse“

Dimensions

The Pentacon Six standard screen is approximately 50.69 mm wide by 50.66 mm from front to back.  (These dimensions are approximate, but were derived from repeated measurements with an electronic digital calliper.)  It must be assumed that the other Pentacon Six screens will have horizontal dimensions that are for all practical purposes the same.  In at least one case (the fresnel screen), the thickness of the screen is substantially different.
 

2) Groundglass screen with Rangefinder wedges
 

The groundglass screen with rangefinder wedges [rfscrn.jpg]

English description (from 1974 English catalogue) Groundglass screen with range-finder wedges within the groundglass area (Part Number 207370) (subsequently re-numbered 207375) Intended use: “additional focussing aids (Rangefinder wedges)” (translation of the German below). Deutsch (von „Pentacon Zubehör für Spiegelreflexkameras“ 1975) Bildeinstellsystem: mattierte Bildfeldlinse mit Meßkeilen (Sach-Nr. 207375) Vergesehene Benutzung: (vom Prospekt „Pentacon Zubehör für Spiegelreflexkameras“ 1975)  „zusätzliche Einstellhilfe (Meßkeilen)“

 

Other information W G Heyde, in seinem „Praktisix Buch“ (1964) schreibt (page 26):  „Die Mattscheibe, wie wir sie von der Plattenkamera her kennen, ist bei der PRAKTISIX durch eine Bildfeldlinse ersetzt.  Diese plankonvexe Linse, mit mattierter Fläche auf der Planseite, hat gewölbte Form.  Dadurch erscheint das Bild bis in die Ecken hell. (Sie ist gegen andere Feldlinsen austauschbar.)“ Auf der Seite 149 des selben Buches beschreibt er diese Einstellscheibe auf folgender Weise: „a) Mattierte Bildfeldlinse mit Meßkeilen zur Entfernungseinstellung (Meßlupe).“ In seinem Buch, „Pentaconsix Praxis“ 3., verb. Auflage, Leipzig 1980 (Seite 194) schreibt er: „Für Spezialzwecke kommen zum Auswechseln als Bildeinstellsysteme in Frage: 6) Bildfeldlinse mit Meßlupe.“

My English translation W G Heyde, in his „Praktisix Buch“ (1964) writes (page 26):  “The ground glass screen that we know from plate cameras is in the PRAKTISIX replaced by an image field lens.  This planoconvex lens, with a ground glass surface on the flat side, has a domed or convex upper surface.  In consequence of this the image appears bright right into the corners.  [TRA: wishful thinking]   It can be exchanged for other field lenses.” On  page 149 of the same book he describes this particular screen as: “Ground glass image field lens with rangefinder wedges for setting focus (Measuring magnifying glass or loupe).” In his book „Pentaconsix Praxis“ 3rd, improved edition, Leipzig 1980 (page 194) he writes: “For special purposes it is possible to change the image focussing system: 6) Image field lens with measuring magnifier”

 

3) Groundglass screen with clear field and hairline cross
 

The groundglass screen with clear field and hairline cross [mattstkz.jpg]

English description (from 1974 English catalogue) Groundglass area with clear field and hairline cross (Part Number 207330) (subsequently re-numbered 207335) Intended use: “Special focussing screen for Loupe, Microscope of astronomical (telescope) photographs, for spectroscopic and endoscopic (medical) photography, with a clear field so that focussing can be carried out with greater accuracy using the bright aerial image” (translation of the German below). Deutsch (von „Pentacon Zubehör für Spiegelreflexkameras“ 1975) Spezialbildfeldlinse: mattiert, Klarfeld 6mm dia und Strichkreuz (Sach-Nr. 207335) Vergesehene Benutzung: (vom Prospekt „Pentacon Zubehör für Spiegelreflexkameras“ 1975)  „Spezialbildfeldlinse für Lupen-Mikro oder Astroaufnahmnen, für die spektroskopische und endoskopische Fotografie mit Klarfeld, damit das Scharfeinstellen mit größter Genauigkeit direkt nach dem hellen Luftbild vorgenommen werden kann.“

 

Other information W G Heyde, in seinem „Praktisix Buch“ (1964) schreibt (page 149): „b) Mattierte Bildfeldlinse mit Fadenkreuz im Klarfeld (6mm) für Makro und Mikro“ In seinem Buch „Pentaconsix Praxis“ 3., verb. Auflage, Leipzig 1980 (Seite 188) schreibt er: „Bei Reproaufnahmen …  Die auswechselbare mattierte Bildfeldlinse mit Fadenkreuz im Klarfeld erlaubt präzise Scharfeinstellung auch bei geringer Helligkeit.  Die Schärfe prüft man, indem man das Auge über der Lupe etwa hin und her bewegt, dabei darf sich das im Klarkreis sichtbare Luftbild gegenüber dem Fadenkreuz nicht verschieben.“ Auf der Seite 194 desselben Buches schreibt er: „4) Bildfeldlinse mit Klarfeld und Fadenkreuz, mattiert für Nah- und Mikroaufnahmen, Scharfeinstellung mit Hilfe des hellen Luftbildes und des Fadenkreuzes.“   Ursula Petsch, in ihr Buch „Pentacon Six“ (Leipzig, 1986), schreibt (page 210): Bildfeldlinse mit Klarfeld und Fadenkreuz, mattiert „zum Scharfeinstellen auf das Luftbild bei Nah-, Makro- und Mikroaufnahmen (nicht geeignet für Aufnahmen mit Teleobjektiven).“

My English translation W G Heyde, in his „Praktisix Buch“ (1964), writes (page 149): “Ground glass image field lens with hairline cross in a clear field (6mm) for macro and micro photography.” In his book „Pentaconsix Praxis“ 3rd, improved edition, Leipzig 1980 (page 188) he writes: “For reproduction photography ...  the interchangeable ground glass image field lens with hairline cross in a clear field permits precise focussing even in low light.  One can check the sharpness by moving one’s eye to and fro over the focussing screen, during which the aerial image in the clear circular area must not move in relation to the hairline cross.” On page 194 of the same book he writes: “4) Image field lens with clear field and hairline cross, ground glass, for close-up and micro photography, focussing with the help of the bright aerial image and the hairline cross.” Ursula Petsch, in in her book „Pentacon Six“ (Leipzig, 1986), writes (page 210): “Image field lens with clear field and hairline cross, ground glass For focussing on the aerial image for close-up, macro and micro photography (not suitable for photography with telephoto lenses).”

4) Groundglass screen with 10mm squares
 

The ground glass screen with 10mm squares, with a sample of the grey boxes in which these screens were sometimes supplied [gg10mmbx.jpg]

English description (from 1974 English catalogue) Groundglass area with 10mm squares (Part Number 207340) (subsequently re-numbered 207345) Intended use: “a grid with 10mm × 10mm squares to ensure the setting up of the camera to the exact angle (Reproduction) and to enable speedy confirmation of the reproduction scale in close up, loupe and micro photography” (translation of the German below). Deutsch (von „Pentacon Zubehör für Spiegelreflexkameras“ 1975) Spezialbildfeldlinse: mattiert, Quadratnetz 10mm × 10mm (Sach-Nr. 207345) Vergesehene Benutzung: (vom Prospekt „Pentacon Zubehör für Spiegelreflexkameras“ 1975) „ein Liniennetz mit Quadraten 10mm × 10mm für die winkelgetreue Ausrichtung der Kamera (Reproduktionen) und für das schnelle visuelle Ermitteln des Abbildungsmaßstabes bei Nah-, Lupen- und Mikroaufnahmen.“

 

Other information W G Heyde, in seinem „Praktisix Buch“ (1964) (page 149) beschreibt diese Einstellscheibe auf folgender Weise: „c) Mattierte Bildfeldlinse mit Netzteilung (10mm) zur genauen Ausrichtung von Kamera und Objekt, insbesondere für Reproduktionen.“ In seinem Buch „Pentaconsix Praxis“ 3., verb. Auflage, Leipzig 1980 (Seite 194) schreibt er: „1) Bildfeldlinse mit 10mm-Netzteilung für Reproduktionen und für Aufnahmen mit erforderlicher genauer Ausrichtung der Kamera.“ Ursula Petsch, in ihr Buch „Pentacon Six“ (Leipzig, 1986), schreibt (page 210): Bildfeldlinse mit 10-mm-Netzteilung, mattiert „für Aufnahmen, die genaues Ausrichten der Kamera erfordern, z.B. zum Vermeiden von stürzenden Linien in Architekturfotos; bei Reproduktionen.“

My English translation W G Heyde, in his „Praktisix Buch“ (1964) (page 149) he describes this particular screen as: “Ground glass image field lens with division into grid (10mm) for the precise positioning of camera and object, especially for reproduction photography.” In his book „Pentaconsix Praxis“ 3rd, improved edition, Leipzig 1980 (page 194) he writes: “1) Image field lens with 10mm grid divisions for reproductions and for pictures that require a more precise set-up of the camera.” Ursula Petsch, in in her book „Pentacon Six“ (Leipzig, 1986), writes (page 210): “Image field lens with 10mm grid divisions, ground glass For photographs that require exact setting up of the camera, for instance, to avoid converging lines in architectural photography and in reproduction photography.”

5) Groundglass screen with hairline cross and 5mm graduation
 

The ground glass screen with hairline cross and 5mm graduation [gg5mm.jpg]

English description (from 1974 English catalogue) Groundglass area with hairline cross and 5mm graduation (Part Number 207360) (subsequently re-numbered 207365) Intended use: “5mm divisions for the setting up of the camera to the correct angle (Reproduction) and for the speedy visual confirmation of the reproduction scale in close up, loupe and micro photography” (translation of the German below). Deutsch (von „Pentacon Zubehör für Spiegelreflexkameras“ 1975) Spezialbildfeldlinse: mattiert, 5mm-Teilung (Sach-Nr. 207365) Vergesehene Benutzung: (vom Prospekt „Pentacon Zubehör für Spiegelreflexkameras“ 1975) „eine 5-Millimeter-Teilung für die winkelgetreue Ausrichtung der Kamera (Reproduktionen) und für das schnelle visuelle Ermitteln des Abbildungsmaßstabes bei Nah-, Lupen- und Mikroaufnahmen“

 

Other information W G Heyde, in seinem „Praktisix Buch“ (1964) schreibt (page 149): „e) Mattierte Bildfeldlinse mit Achsenkreuz und 5mm-Teilung zur Einhaltung bestimmter Abbildungsmaßstäbe“ In seinem Buch „Pentaconsix Praxis“ 3., verb. Auflage, Leipzig 1980 (Seite 194) schreibt er: „2) Bildfeldlinse mit Achsenkreuz und 5mm-Teilung, mattiert für maßstabgebundene Reproduktionen.“ Ursula Petsch, in ihr Buch „Pentacon Six“ (Leipzig, 1986), schreibt (page 210): Bildfeldlinse mit Achsenkreuz und 5-mm-Teilung, mattiert „zur Kontrolle des Abbildungsmaßstabes bei meßtechnischen oder für wissenschaftliche Zwecke auszuwertenden Aufnahmen, für Reproduktionen.“

My English translation W G Heyde, in his „Praktisix Buch“ (1964) writes (page 149): “Ground glass image field lens with axial cross and 5mm marking in order to maintain selected imaging scale.” In his book „Pentaconsix Praxis“ 3rd, improved edition, Leipzig 1980 (page 194) he writes: “2) Image field lens with axial cross and 5mm divisions, ground glass, for reproductions that require a fixed scale.” Ursula Petsch, in in her book „Pentacon Six“ (Leipzig, 1986), writes (page 210): “Image field lens with axial cross and 5mm divisions, ground glass For the control of image scales for images that are to be evaluated for technical measuring or scientific purposes, for reproductions.”

6) Clear glass screen with hairline cross and 5mm graduation
 

The clear glass screen with hairline cross and 5mm gradation [klar5mm.jpg]

English description (from 1974 English catalogue) Clear glass area with hairline cross and 5mm graduation (Part Number 207350) (subsequently re-numbered 207355) Intended use: “Special focussing screen for loupe, microscope and astronomical (telescope) photography, for spectroscopic and endoscopic (medical) photography, clear glass, so that focussing can be carried out with greater accuracy using the bright aerial image” (translation of the German below). Deutsch (von „Pentacon Zubehör für Spiegelreflexkameras“ 1975) Spezialbildfeldlinse: unmattiert, 5mm-Teilung (Sach-Nr. 207355) Vergesehene Benutzung: (vom Prospekt „Pentacon Zubehör für Spiegelreflexkameras“ 1975) „Spezialbildfeldlinse für Lupen-Mikro oder Astroaufnahmnen, für die spektroskopische und endoskopische Fotografie unmattiert, damit das Scharfeinstellen mit größter Genauigkeit direkt nach dem hellen Luftbild vorgenommen werden kann.“

This screen is sometimes referred to as “PENTACON SIX KLARLUPE + FADENKREUZ 5mm”  A description of it in a (West) German catalogue from the 1970s says that this screen is “especially suited to the micro-range (perhaps macro photos, but especially photos through a microscope) and for the photography of objects with a fine structure)”.
 
 

Other information W G Heyde, in seinem „Praktisix Buch“ (1964) schreibt (page 149): „d) Unmattierte Bildfeldlinse mit Achsenkreuz und 5mm-Teilung für Mikroaufnahmen“ W G Heyde, „Pentaconsix Praxis“ 3., verb. Auflage, Leipzig 1980 (Seite 194): „3) Bildfeldlinse mit Achsenkreuz und 5mm-Teilung ..., unmattiert für Mikroaufnahmen.“ Ursula Petsch, in ihr Buch „Pentacon Six“ (Leipzig, 1986), schreibt (page 210): Bildfeldlinse mit Achsenkreuz und 5-mm-Teilung, unmattiert „für Mikroaufnahmen mit starker Vergrößerung und in Verbindung mit Geräten, die nur ein licht-schwaches Bild liefern (Medizin: Endoskop u.a.).“

My English translation W G Heyde, in his „Praktisix Buch“ (1964) writes (page 149): “Clear glass image field lens with axial cross and 5mm markings for micro photography.” In his book „Pentaconsix Praxis“ 3rd, improved edition, Leipzig 1980 (page 194) he writes: “3) Image field lens with axial cross and 5mm divisions ..., clear glass, for micro photography.” Ursula Petsch, in in her book „Pentacon Six“ (Leipzig, 1986), writes (page 210): “Image field lens with axial cross and 5mm divisions, clear glass For micro photography with large degrees of enlargement and in connection with equipment that deliver only images with weak light levels (Medicine: endoscopy, etc.)”

7) Fresnel screen
 

The fresnel screen installed in a late-production Pentacon Six TL [fres_top.jpg]

English description (from 1974 English catalogue) Fresnel lens (Part Number 207251) (subsequently re-numbered 207261)  Intended use: “image-brightening fresnel lens with focussing aids (Ground glass surface ring and microprisms)”. Deutsch (von „Pentacon Zubehör für Spiegelreflexkameras“ 1975) Fresnellinse mit Mattscheibenringfeld und Mikroprismenraster (Sach.-Nr. 207261) Vergesehene Benutzung: (vom Prospekt „Pentacon Zubehör für Spiegelreflexkameras“ 1975) „bildaufhellende Fresnellinse mit Einstellhilfen (Mattscheibenringfeld und Mikroprismenraster).“

Important note: the image resolution, my computer screen and the dimensions of the fresnel rings on this focussing screen are combining to display an irregular pattern on my monitor.  Such a pattern is not visible on the fresnel screen itself; it is merely a result of the interference caused by the sizes of the pixels and the computer screen resolution in relation to the fresnel rings.  (For the same reason, this moiré interference may not be visible on your monitor either.)
 

Substantial enlargement of part of the fresnel screen [frescent.jpg]

The substantial enlargement on the left of a part of the fresnel focussing screen shows the three sections of the screen: a) the central disk with microprisms to aid focussing b) the clear ground glass ring around it to aid focussing c) the fresnel rings on the rest of the screen, which give a bright image right into the corners. You can see further pictures of the fresnel screen here.   Brightness and focussing compared very well with the focussing experience with the high quality 35mm camera that I had at the time, a Minolta SR-T 101.  However, in my opinion, better screens were subsequently developed for both 35mm and Medium Format cameras.  One such better screen is described next.

Other Screens

Some other screens are sometimes available for the Pentacon Six. 

"Mystery" screen

"Mystery" screen [mysscrn2.jpg] This screen doesn't appear in any catalogue or book that I have seen, and unfortunately it came without a box, so I don't have a part number.

[mysscrn1.jpg] The screen has the same "wedge" shape as all the GDR screens for the Pentacon Six except the fresnel screen (see higher up on this page), which is flat. Most of the screen consists of a ground-glass surface, just like the standard Pentacon Six screen and most of the other East German screens shown above.

[mysscrn3.jpg] By looking at a massive enlargement of the centre of the screen (and increasing the contrast of the image!), we can see that the central area consists of microprisms that are designed to facilitate focussing.

Perhaps this was a prototype that was never marketed.

The Exakta 66 Mk 2/Mk 3 Rollei screen
 

The Rollei MKPG screen for the Exakta 66, installed in one of these cameras [C387_30A.jpg]

This is the screen that was supplied with some Rollei cameras from the 1980s on and was supplied as standard with the Exakta 66 Mk II and Mk III (from about 1989).  According to the Exakta 66 Technical Data Sheet dated January 1990 (“EXAKTA 66 Technisches auf einen Blick”), the letters that are often given as the screen name, MKPG, are an abbreviation for “Messkeil, Mikroprismenring, Gitterraster”, which means “Rangefinder wedges, Microprism ring, gridlines”, which is a reasonably accurate summary of the features of this screen. It is a fresnel screen of approximately the same brightness as the GDR Fresnel screen (no. 7, above), but in my opinion the addition of rangefinder wedges inside a ring of microprisms makes focussing easier in most circumstances.  The faint gridlines are aids to keeping the camera horizontal, vertically parallel to the subject, etc. and in my opinion do not detract from the viewing experience. The screen needs to be bought with the correct retaining wire, screw and clip (see below). It also fits the Pentacon Six perfectly. More information on this screen can be found, with details of suppliers, here. Note: This screen is every bit as bright as the GDR fresnel screen.  I have deliberately reproduced it somewhat darker here, to enable you to see the focussing aids to some extent.

Additional pictures of the MKPG Rollei screen for the Exakta 66
 

The top of the Rollei MKPG screen for the Exakta 66 The gridlines, which appear white (and hard to see) in this image and the next one, show up as faint dark lines when the subject is viewed on the screen in the camera. [mkpg3c.jpg]

The underside of the same screen Here I have put it on a dark background and sharpened the image on the computer, to make it easier to see the grids and rangefinder wedges. [mkpg7.jpg]

The fixing wire, clip and bolt required for this screen [mkpg1.jpg]

The Kiev 60 screen

The screen that is supplied with the Kiev 60 camera is brighter than the standard Pentacon Six screen, but it is not the right size for this camera.  If you are considering buying one, it is essential to be sure that it has been cut down to the right dimensions to fit the Pentacon Six.  Also check that it is supplied with something suitable to hold it in place in the Pentacon Six.  I would advise against trying to cut a screen down to size oneself, as they are so fragile that they can be easily damaged or can shatter.

To see a review of a focussing screen from Kiev, click here.  I am not sure whether this is a cut-down standard Kiev 60 screen, a Kiev 88 screen, or a totally different screen.

Dimensions of camera top cover focussing screen opening

Pentacon Six: 51.69 mm (left-right) × 51.86 mm (front-back).
Kiev 6C: 54.38 mm (left-right) × 52.89 mm (front-back).  (The dimensions of this opening on the top plate of the Kiev 60 would appear to be the same as on the Kiev 6C, since the same waist-level finders and prisms are equally usable on either camera.)
These dimensions are approximate, but were derived from repeated measurements with an electronic digital calliper.  Naturally, the dimensions of the focussing screen in each case will be somewhat smaller than the opening.
 

Other screens

At various times some other screens are offered for the Pentacon Six.  Maxwell screens have a deservedly high reputation, but I don’t know if one has ever been offered for the Pentacon Six.  They are also usually quite expensive.  I have received negative reports on some other screens, but have no personal experience of them in a Pentacon Six.

To see notes on how to change focussing screens, click here.

To go to introduction to the cameras, click here.

To go back to the section on viewing aids, click here.

To choose other options, click below.
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© TRA First published: November 2011, latest revision: January 2016