Diese Seite auf Deutsch
Extension Rings
Extension Rings | Extension Rings II AR / 2 AR | Extension Rings 3 AR
For the Konica SLR system, extension rings for close-up and macro photography are available. Extension rings extend the distance between film and lens, such causing a projection of the image. Due to this projection, the image gets larger, but also darker, because not all light passing the lens is hitting the film. With extension rings in place, the lens cannot be focused to infinity.
Without reverse ring, magnification ratios of up to 1:1 can be achieved with the Konica extension ring sets for the AR bayonet and a 50 mm standard lens. With the reverse ring, which was part of the extension ring sets later on, magnification ratios of up to 2:1 could be achieved with a 50 mm standard lens. In this case, the image on the film is twice as big as the subject in reality.
Over the years, there were different extension ring sets available from Konica:
Extension Rings
Extension Rings
An extension ring set for the older 
F bayonet. Consisting of six rings, not numbered. Altogether, the rings are a bit shorter than with later sets, so no 1:1 magnification is achieved with a 50 mm lens. The extension ring set was delivered in a cardboard box with a styropor inlay.
On the only set I've seen so far, the lens base ring is engraved with Konica FP extension. However, the extension ring set can be used with other F bayonet bodies as well, like the Konica FS or FM.
- Chromed base ring with male bayonet for connection to the camera body and a screw thread of 55 mm diameter on the other side; length 5 mm.
- Black distance ring with a length of 5 mm and a screw thread of 55 mm diameter on both sides.
- Two black distance rings with a length of 10 mm each and a screw thread of 55 mm diameter on both sides.
- Black distance ring with a length of 20 mm and a screw thread of 55 mm diameter on both sides.
- Chromed base ring with female bayonet for connection to the lens and a screw thread of 55 mm diameter on the other side; length 3 mm. This ring has a spring-driven claw to close the aperture of the lens. This is necessary with F bayonet lenses, otherwise the aperture would always be open – different from later AR bayonet lenses.
Case Extension Rings
Case Extension Rings open
Extension Rings II AR / 2 AR
Extension ring set Extension Rings 2 AR
The first extension ring set for the newer AR bayonet. Consisting of five rings, numbered from No. 1 – No. 5. With these rings and a 50 mm standard lens, a magnification ratio of up to 1:1 can be achieved.
- No. 1: chromed base ring with male bayonet for connection to the camera body and a screw thread with 55 mm diameter on the other side; length 5 mm.
- No. 2: black distance ring with a length of 8 mm and a screw thread of 55 mm diameter on both sides.
- No. 3: black distance ring with a length of 16 mm and a screw thread of 55 mm diameter on both sides.
- No. 4: black distance ring with a length of 24 mm and a screw thread of 55 mm diameter on both sides.
- No. 5: chromed base ring with a female bayonet for conntection to the lens and a screw thread with 55 mm diameter on the other side; length 5 mm.
The base rings No. 1 and No. 5 are both needed to provide the bayonet connection to the camera and to the lens. The smallest possible extension is 10 mm with these two rings combined. The black distance rings can be screwed in between in any combination, if desired.
Extension Rings 3 AR
Extension ring set Extension Rings 3 AR
The later extension ring set for the AR bayonet, introduced with the Autoreflex T3. This set contains the same rings as its predecessor set 
Extension Rings 2 AR, but on top it contains a reverse ring that enables you to use a lens with a filter thread of 55 mm diameter in reverse position (front element pointing towards the camera). With this extension ring set and the reverse ring, magnification ratios of up to 2:1 can be achieved with a 50 mm standard lens. This extension ring set was delivered with a soft black leatherette case.
- No. 1: chromed base ring with male bayonet for connection to the camera body and a screw thread with 55 mm diameter on the other side; length 5 mm.
- No. 2: black distance ring with a length of 8 mm and a screw thread of 55 mm diameter on both sides.
- No. 3: black distance ring with a length of 16 mm and a screw thread of 55 mm diameter on both sides.
- No. 4: black distance ring with a length of 24 mm and a screw thread of 55 mm diameter on both sides.
- No. 5: chromed base ring with a female bayonet for conntection to the lens and a screw thread with 55 mm diameter on the other side; length 5 mm.
- R: black reverse ring with a length of 35 mm and screw threads with 55 mm diameter, both sides male; one side with pitch of the other extension rings, other side with 55 x 0.75 mm filter thread.
Extension ring set in normal position
Extension ring set in reverse position
When the lens is used with normal orientation (front element pointing towards the subject), at least the base rings No. 1 and No. 5 are needed to provide the bayonet connection to the camera and to the lens. The smallest possible extension is 10 mm with these two rings combined. The black distance rings can be screwed in between in any combination, if desired.
The reverse ring of the extension ring set Extension Rings 3 AR is screwed in place of the base ring No. 5 (with the female bayonet for the lens) as frontmost ring it screws directly into the filter thread of the lens, no further parts are necessary.
General
The genuine Konica extension ring sets are not the best solution for many reasons. The set-up and changing with the screwed rings is quite cumbersome, a bayonet connection between the rings is much more comfortable. Very annoying is, that the smallest distance ring No. 2 tends to jam on the base ring No. 1, and can then be removed only with patience, because you do not get a good grip on them. In addition, the Konica extension rings do not provide automatic aperture functionality and therefore the fully automatic AE exposure control is lost. The extension rings can be combined with the Auto Ring and Double Cable Release, in this case at least the automatic closure of the aperture when releasing the shutter is possible.
Some third-party manufacturers offered automatic extension ring sets (mostly consisting of three rings), that had a bayonet connection between the single rings and provided aperture coupling. It's far more comfortable to work with these extension ring sets than with the genuine original Konica accessories. As extension rings do not contain any optics, there is no reason to fear worse image quality than with the genuine Konica extension rings.
The original extension ring sets for the AR bayonet as well as the third-party sets are being offered frequently and do not cost much. Certainly a rewarding investment, that extends the possibilities of the system substantially.
Caution!
The threads for the connection between the extension rings also have a diameter of 55 mm, but they have a different pitch from the standard filter thread. Never screw an extension ring into the filter thread of a lens, you could damage both threads. For the same reason, make sure the reverse ring has its proper orientation.
Never connect the male bayonet of base ring No. 1 with the female bayonet of the base ring No. 5. If the bayonet is locked, both rings can only be separated with great difficulties – the locking lever cannot be pressed in sufficiently to free the bayonet lock.
Attachment lens or extension rings?
In a certain range, desired magnification ratios can be achieved with attachment lenses as well as with extension rings. Which gives the better results?
A widespread misconception is, that extension rings do not harm image quality because there are no optical elements inside. But the change of the lens-film distance which causes in fact a projection of the image is also a big change in the optical system. With some lenses, the use of extension rings can cause a dramatic fall-off in sharpness towards the corners and edges. If this is the case, is depending on the lens' optical construction and must be tested with the specific lens.
Mostly well-suited for use with extension rings are prime lenses with a moderate speed for their focal length, like i. e. a Hexanon AR 50 mm / F1.7. Such lenses usually give better results with extension rings than with attachment lenses.
Mostly not very well-suited for use with extension rings are zoom lenses or lenses with internal focusing. Extremely fast lenses also can be critical. With such lenses, attachment lenses frequently give better results than extension rings.
More pages on Konica accessories:
Overview | Flashes and strobes | Close-up and macro accessories | Winder | Battery compartments | Lens mount adapters | User's manuals | Top of page
E-mail