Minolta SR-T 101

image by Dries van den Elzen (Image rights)

The camera

in black image by KWANON-D (Image rights)

The Minolta SR-T 101 is a 35mm SLR camera made by Minolta Camera Co. Ltd, Japan, premiering in the March 1966 Japan Camera Show . Sales began in April 1966 and it stayed in production with only minor changes for ten years, the result of the thorough development effort that was put into the camera. The body is a direct continuation of the Minolta SR-7 model V of 1962, itself an innovative camera. However, the SR-T 101 has many significant features apart from the TTL meter. Perhaps the most notable one was the full aperture metering facility, which automatically compensates for the speed of the lens fitted on the camera at any time, a feature it took Nikon twelve more years to figure out how to accomplish. Full aperture metering in 35mm SLR cameras was pioneered by the brilliant Tokyo Kogaku Topcon RE Super, a feature lacking in every screw mount camera until Olympus Kogaku introduced the Olympus FTL, their first full frame 35mm SLR in 1971, which was abandoned one year later in favour of the OM system.

The first generation camera body serial numbers started from 1000xxx (see section below). When first introduced, the standard kit lens was the 58mm/f1.4 MC Rokkor-PF, with 6 elements in 5 groups, beginning from lens serial number 5000xxx. About four months after launch, the 55mm/f1.7 MC Rokkor-PF, 6 elements in 5 groups, was added as an alternate kit lens. Then in September 1968, the 58mm/f1.2 MC Rokkor-PG, 7 elements in 5 groups with 8 aperture blades, became available. These earlier kit lenses featured knurled metal barrels, versus later rubber-gripped MC Rokkor-X (or MC Rokkor) versions. A very well crafted ever-ready case was available in either brown or black leather to protect the camera with normal lens. A longer-nosed black ever-ready case was made for the SR-T101 and 58mm/f1.2 combination.

image by Steve Harwood (Image rights)

The SR-T has an extremely bright finder with a central micro prism focusing aid that proves to be very accurate in most cases, since even when no visible lines are present in the subject, all out-of-focus objects appear to shimmer. Two exposure meter needles and the selected shutter speed are shown in the viewfinder. A small rectangle to the right indicates the acceptable needle deflection range for a healthy battery when the ON/OFF switch on the camera base is set to the battery check position labelled BC. Battery power is saved by placing the switch in the OFF position whenever the camera is not used. Battery power may also be saved by keeping the lens cap on whenever possible, since the exposure meter draws current in proportion to light intensity entering the camera lens. The metering circuit is dependent on an obsolete mercury battery. It may be replaced using a zinc-air hearing aid 1.4-volt battery, which usually comes in a six-pack and is not very expensive.

Several internal parts may fail on a forty-year-old camera, and the SR-T 101 is no exception. The only serious trouble is related to the exposure meter movement itself, in which the tiny coil tends to break, this situation requires a replacement. The back door rubber sealing foam will usually need replacement, and so will a small strip of same cushioning the mirror when it goes up. A strip of this may be cut from a similar sealing material from a hardware store. All other problems are easily put right with a minimum of effort and tools, unless the camera is worn out, which rarely happens. In fact, anybody who figures out how to remove the top cover without causing any damage may repair it oneself.

How old is my Minolta SR-T 101?

First version SR-T101 (note shutter speed dial) image by Siim Vahur (Image rights)

During the ten-year manufacturing period of the Minolta SR-T101, many small changes were made to the camera body. Several of these changes are easily detected and they can help determine time of manufacture to within a few years. It should be noted that any part of a camera may be replaced due to repair and smaller parts are more easily swapped, but normally these features may be considered original. Top cover and base plate are parts usually replaced due to impact damages, and a replacement top cover would not have the original serial number.

1966-late 1969: the first generation 101’s have a finely-knurled black shutter speed barrel (even on chromed body models), and have single slot screws holding the base plate and top cover on, while later generations use Phillips head screws. From 1966 into 1967, the two screws at the back of the top cover were the same distance from the eyepiece, while on all later SR-T‘s the right-hand screw is farther away from the eyepiece. From 1968 on, the black plastic shoulder pieces between the front cover and the top cover are held in place by visible screws. In Fall 1968 Minolta began selling black body SR-T101's, like image at left, from serial number 1270xxx on.

1970-1973: the second generation and later 101’s have a coarse ridged chromed shutter speed barrel. From 1972 on, as seen on the inside of the top cover, the film counter clear plastic window is glued in place, while on earlier versions it is held in place by an internal bracket.

1973-1975: on the third generation 101’s, the black plastic piece under the accessory shoe protrudes up forming a ridge in front of the shoe, while earlier versions have a single metal peg.

The lack of mirror lockup (MLU) on an SR-T101 is not an exact indicator of its age. MLU first began to be discontinued early in the transition to the second generation, but did continue at least until the third generation SR-T.

Metering: CLC and full aperture TTL

Camera ads from the 1970s boast of its CLC (Contrast Light Compensator) metering, calling it "the brain". CLC is a form of TTL metering with two CdS cells. It compensates for over-exposure by assuming that the upper side of the picture is the sky (overcast) and that the lower part is the subject you want to photograph. ISO values can be set from 6 to 6400.

viewfinder

The SR-T 101's viewfinder shows the exposure meter needle at the right side of the finder image. This needle shows the actual light value coming in through the lens at maximum aperture, with lower indicating a higher light value. The needle's position is not dependent on film speed or any other camera setting; it will be constant for a given light value and a given lens. Also at the right is a follower needle with a circle at the tip. This indicates the current exposure value calculated from film speed, number of stops below maximum aperture, and shutter speed. By changing one or more of these inputs, this circle can be made to overlap the meter needle, at which point the exposure will be approximately correct. The second image shows the meter in battery control mode: needle over the little rectangle means correct voltage.

The Minolta SR-T 101 was one of the first cameras to have full aperture TTL metering. This was possible thanks to the fact that Minolta had placed the aperture ring on its Rokkor MC lenses close to the camera body. This way, the position of the aperture ring could be communicated mechanically to the metering system inside the camera. What is actually transmitted is not the aperture itself, but the offset between the selected aperture and the lens' maximal aperture.

Other specifications

• The SR-T 101 has a cloth focal plane shutter with speeds from 1 sec to 1/1000. The film advance lever automatically cocks the shutter, preventing double exposures. Shutter speeds are shown at the bottom of the viewfinder.

• It has some interesting features which set it apart from many other SLRs of that time, like mirror lockup, a mechanical self-timer and a depth-of-field preview button.

• The manual-focus Rokkor lenses have a very good reputation and some are very fast: the fastest standard lens in SR-T101 time was 58mm f/1.2 MC Rokkor PG.

• The SR-T 101 uses a PX625 cell for the metering system only. With a dead battery, all functions but the meter will continue to work.

Links

• Minolta SR-T series; an overview of features.
• Review at Classic Cameras
• Rokkor files
• SR-T 101 Manual (JPEG Scans)
• SRT-101, SRT-101 noir, SRT-101b on www.collection-appareils.fr by Sylvain Halgand (in French)
• Minolta SR-T 101 page at Camera Portraits
• Minolta SR-t 101 camera manual, German version available, repair manual from OrphanCameras.com