Konica Auto S2
From Silvergrain Labs
Konica Auto S2 is a fixed lens rangefinder camera from early 1970s. This is a relatively inexpensive but very good camera with excellent lens. Although this camera is still highly usable, there are many age-related problems that can be serviced with no replacement parts.
Other keywords: コニカ 小西六 オートS2 レンジファインダー コパル SVA 内部構造 修理 レストアー
Contents |
The camera and the lens
This is a fixed lens rangefinder camera featuring excellent optics and reliable shutter. Besides it's a bit bulky, this camera is still usable and delivers excellent image quality after 40 years of manufacturing.
Konica released world's first camera to use CdS photoresistor to implement auto exposure program, Konica Auto S, featuring 47mm f/1.9 lens in 5e5g construction, in April 1963. Auto S2 is the improved version featuring the larger f/1.8 lens, released in December 1964.
| Specification | |
|---|---|
| Lens | Konica Hexanon 45mm f/1.8, 6 elements in 4 groups |
| Filter size | 55mm (same as many lenses in Konica AR lenses for SLR's) |
| Shutter speed range | 1 sec to 1/500 sec, plus bulb |
| Aperture range | f/1.8 to f/16 |
| Meter | CdS meter |
| Exposure automation | shutter priority lock needle auto exposure mode |
| Film speed range | ASA 25 to 400 (for meter) |
| Battery | 1 PX625 (1.35V mercury cell) |
| Dimension | 138x82x74mm, 750g |
Related sites
Sample Photos taken with Auto S2
Inside Konica Auto S2
Copal-SVA shutter
Disassembling the front lens assembly, you'll reach the Copal-SVA lens shutter. Left: This is the view of the shutter speed cam with all the pins engaged. When you remove this cam, there will be two loose parts to come together. Right: The cam, shutter speed click spring, and the self timer lever cover. These pieces are shown in place in the shutter unit in the following picture (Left).
Right is a closeup of the self timer escapement. On the other side of the lens, you'll see the shutter timing escapement and the other driving parts.
The front panel is removed to expose the driving mechanism for the aperture diaphragm.
The body part has the winding shaft (to charge the shutter), winding reset for the diaphragm drive (for auto mode), the lock-needle aperture lever from the meter assembly and the shutter release lever.
As you see, there are many things that engage between the body and the front panel, but it only requires to push in the arch shaped lever before reassembling the front plate. Of course, both the shutter and the body winding crank should be in uncharged state.
Rangefinder and Viewfinder System
The rangefinder system is very well designed and well made. The calibration is done by one screw behind the diagonal mirror on the right. This system is better than the rangefinder system of the competitor, such as Minolta Hi-Matic 7s. The half mirror, diagonally placed on the left, is very delicate; don't try to do anything m ore than blowing dusts off and gently wiping with dry cotton swab. The parallax compensating framelines (right) are made by this part, right above the cam that receives focusing distance information from the lens.
The light meter reading is shown in the viewfinder via a narrow strip of mirror placed in the light meter assembly. More later on this topic.
Light meter
Left: From the top of the meter, you see that there are two scales. One is for viewing on the top panel, and the other is for the projection into the viewfinder. The printing for the viewfinder projection is shown backward because it'll be reflected by the mirror (the left diagonal mirror) once before seen by the operator. The light used to project the meter reading is taken from the top panel. Very clever design.
Right: The same meter but the tiny mirror strip taken off. The plastic cover indicates that the meter assembly was manufactured by Sekonic. The plastic cover has a stamp imprinting 47.11.16 and he actual meter inside is marked by handwriting 47 11 20. These are dates, but 47 means 1972 in Japanese calendar. (Showa 昭和 47 is 1972.)
Auto S2 has shutter priority exposure automation by lock-needle mechanism. The meter displays proper aperture value for the chosen shutter speed, and when the shutter button is halfway depressed, the needle is locked and the deflection of the needle is read off by staircase plate. For this reason, the meter of this camera has two needles: one for display, and one for driving aperture control cam in auto mode. The two needles are shown below:
Right: In this view, the light meter assembly is unscrewed and lifted up a bit.
In the auto mode, the camera locks the shutter release button if the proper aperture value is outside the range of this camera, i.e., 1.8 to 16. The lever comes out on the lower left of the meter (shown in the above picture) prevents the shutter release shaft from being depressed beyond a certain point, preventing exposure. This is a very neat feature, because accidental shutter release can be prevented while carrying the camera, as long as you have the lens cap on. (the light sensor, CdS cell, is placed right by the lens inside the filter ring.) Sometimes, this lever gets sluggish or stuck. In that case, the camera fires in auto mode even if the needle indicates proper f-stop value is smaller than 1.8 or greater than 16. When this happens, the plastic cover must be taken off. (It's a bit of PITA, because you'll have to remove the mirror strip shown above, before the plastic cover is removed. This mirror strip is a bit of PITA to place it back on.) The fulcrum of the lever needs one drop of a nonpolar solvent, such as Goof Off. Work out the lever and let it dry.
Left: Once the clear cover is removed, the meter mechanism is visible very clearly. Right: The light meter is driven by one PX625 mercury cell. The wiring around the battery well and battery test button is shown here.
Frame counter
In order to remove the light meter assembly, you'll have to remove the frame counter. It's a typical design of frame counter, certainly very similar to other Konica cameras of the time.
