2other Minolta cameras in my collection


JapanMinolta SRT 101* [1966 - 1975]

* I have removed the hyphen in SR-T because Google does not seem to like it!



The 101 was the first of a series of SRT models, and one of the earliest cameras to feature through the lens metering at full aperture. More than that, the metering system is often sited as the first example of what was to become known as matrix or evaluative metering: where the camera measures the light intensity at several points in the scene, and then combines the results in a way that finds the best exposure. Minolta called their metering system the Contrast Light Compensator (CLC).

Minolta SR-T 101 advertThe metering system employs two separate cells, situated at the top and bottom frame edges, which measure the light falling on different parts of the view, and therefore assumes a typical shot comprises something similar to a bright sky and darker foreground. According to Minolta's Technical Buletin A, these cells are connected in series rather than parallel. When connected in parallel, each cell functions independently, thus the combined reading is an average. Connection in series means one cell has an influence on the other. The CLC circuit allows the identification of discrepancies between the two cell readings, and if there is little contrast, those readings are averaged. However, where there is more significant disagreement, then the CLC compensates to reduces underexposure of shadows, or other dark areas, and minimises the influence of particularly bright regions.

Test exposures with my example show the metering system to be bottom-weighted, and the CLC system appears to guide the user towards increased exposure when the scene has a contrasting dark foreground, but decreased exposure when the foreground is bright (i.e. the camera meters the same scene differently right-way-up to up-side-down). The CLC system is credited with working well (which I don't doubt), BUT other manufacturers didn't jump on the band wagon, and centre-weighted average brightness metering patterns dominated elsewhere. I suspect there are circumstances where the CLC system is fooled, for example, the bias is not designed for contrast in portrait format shooting.

Other key features include an unusual spring loaded mirror stop. This intercepts the mirror at about 4/5ths of its travel, and slows it gently. There is a viewfinder display of the selected shutter speed, a mirror lock-up (see panel left or click here), a depth of field preview button, a viewfinder based battery check, and a strange ASA/DIN converter dial on the back cover. A further odd feature is the meter needle pointer moves the wrong way; it moves towards the bottom of the viewfinder to indicate increased brightness, and conversely the top when the light is dull.

SRT 101 was accompanied by a new range of MC (meter coupled) lenses incorporating a lever that communicates the aperture of the lens to the camera body. The standard lenses for the Minolta SRT 101 were an MC Rokkor-PF f/1.4 f=58mm, an economy f/1.7 55mm, or a deluxe f/1.2 58mm. The camera was also offered as a limited edition black finish.

The cost of the SRT 101 will have varied during its long production run, but in 1968 (the closest date I can get to launch), the price with an f/1.7 lens was £139 - 19s - 6d. The average UK weekly wage at that time was about £28, making the price of the Minolta equivalent to five weeks pay. That was pretty much the same price as a Pentax Spotmatic. By 1974, towards the end of its life, the SRT101 sold for £112.95 (and was still the same price as the equivalent Spotmatic), but in real terms this was a little less than twice the average UK weekly wage.

On paper, the SRT 101 should have blown-away the competition. Millions were made and sold, but in my world, the camera never entered the popular culture and is a model I wasn't even aware of during it's entire lifetime! I find it somewhat ironic that in the replacement model - the SRT 101b - the two most celebrated features, the CLC and mirror lock-up, were dropped!



During its ten year production, the SRT 101 underwent a few changes; the following list is not exhaustive, and pitched towards easy age identification of SRT 101s.

  • Between 1966 and 1967, the two screws at the back of the top cover were the same distance from the eyepiece, while on later examples the right-hand screw is further away.
  • From 1968 onwards, the black plastic shoulder pieces between the front (mirror box) and the top covers are held in place by visible screws.
  • Models made up to late 1969 all have a finely-knurled black shutter speed barrel, and slot screws holding the base plate and top cover on. In 1969 Minolta switched to cross-head screws and the shutter-speed dial was changed to chrome a with a knobby edge.
  • From 1972 onwards, the film counter clear plastic window is glued in place, while on earlier versions it was held in place by an internal bracket.
  • From 1973 onwards, the black plastic piece under the accessory shoe protrudes to form a ridge in front of the shoe, while earlier versions have a single metal peg.
  • Towards the end of SRT 101 production the mirror lock-up feature was removed, but examples are (apparently) relatively rare. This was done because the 21mm Minolta lens was redesigned, and no longer intruded into the mirror box sufficiently to foul the mirror.




Lens mount: Minolta SR bayonet for Minolta MC lenses, with mirror lock-up for ultra-wide angle lenses. MD lenses can also be used.

viewfinderFocus: life-size 1x magnification showing 93% film-frame area. Fresnel lens and micro-prism spot. Battery check, and pointer display of shutter speed. DOF preview.

Shutter: Cloth horizontal travel focal-plane type. speeds: 1/1000 to 1 sec +B and 10 sec self-timer.

Meter: Full-aperture TTL bottom-weighted using two CdS cells and CLC system. On/off switch on base plate.

Exposure: Manual match-the-needle.

Film Speed: 6 to 6400 ASA.

Flash: FP and X terminals with X-sync at 1/60th.

Film Advance: Single or multiple stroke advance lever; 150° setting angle; 20° standoff position.

Frame Counter: Automatic count-up and reset.

Rewind: Via crank and bottom release button.

Size: 145 x 89 x 94.5mm (W x H x D)- with lens.

Weight: 990g (with f/1.4 lens).

Battery: 1.35v 625R type mercury cell.


My Camera

I bought my SRT 101 in March 2017. While I've been searching for one of these, there seems to have been a lot of 101s offered for sale with non-working meters, or ceased shutters and film transport mechanisms. This one was advertised as being in FWO. I did not expect my £20.00 bid to be successful, since camera bodies with broken meters have been achieving more that, but I got lucky. I suspect this may have been because the camera was sold as a bundle with a Tokina 35-70mm zoom lens and a Miranda flash gun (such low-value extras often seems to put off buyers)? Or, maybe the lack of bids was due to the clocks going forward to BST on the morning of the auction end? Whatever ... it's the first camera added to my collection in 2017.

My camera is post 1969, with the chromed shutter speed dial. The self-timer arm has been fiddled with and has an exposed slot-head fixing screw rather than a cover (I don't dare try it: I'm not bothered whether it works). There is a slight knock-ripple in one corner of the top plate but the damage is very minor. The Viewfinder shutter speed pointer doesn't register above 1/30th, but I can live with that. The viewfinder has some dust, but nothing intrusive, and the whole camera arrived in need of a good clean. The light seals and mirror damper are non-existent (Minolta SRT type light seal replacement instructions), and the exposed metal edge at the bottom of the back door needs some repainting. Thankfully, everything significant works ... especially the meter, and I just have easy work to do.

There are some things I like about this camera, and others I'm not so keen on. It's about the same size as a Spotmatic (just a shade taller), but somehow it feels bigger. I like that the meter has an on/off switch, but it's not the easiest thing to operate. The bayonet mount (with it's Nikon style aperture indexing pin) is nice, and I can appreciate why this feature would have made M42 screw threads seem primitive. I also like the compatibility with later MD lenses. I like the large and solid DOF preview/stop-down button, and the fact it locks on the first depress, and releases on the subsequent. I'm not keen on the ASA/DIN converter dial ... it's just a naff feature that says "amateur". The SRT 101 doesn't exude quite the same quality as a Pentax or Nikon, but it's just a personal view. Overall, I think I'm won over by the Minolta, and it's one that will join the queue waiting to be used.



Minolta SR-T 101

Minolta SR-T 101 mirror stop

↑ The sprung mirror stop (shown in blue) is pushed out of position by the inertia of the mirror, reducing mirror slap.

Mirror Lock-up

In recent times, a mirror lock-up has become synonymous with the need to reduce motion blur resulting from mirror slap vibration at slow shutter speeds, but that isn't why the feature came about.

In the case of the SRT 101, the mirror lock-up served a different purpose. It was designed to be use in conjunction with wide angle lenses where the lens intruded sufficiently into the camera body such that the rear element and mirror could come into contact. A mirror lock-up facility was also available on other camera models of the period, such as the Canon FTb, Miranda G, Nikkormat EL and Yashica TL Electro X, for exactly the same reason. The user manuals for these cameras explain this.

Many later cameras didn't feature or need a mirror lock-up, due to advances in lens design (i.e. the retrofocus lens shifted the focal plane further back). It is only in later times that this feature has become desirable for its supposed benefit of reducing vibration at the moment of exposure.

I fully accept that mirror slap can contribute to motion blur at slower speeds. The vibration is present at all speeds, but at higher speeds the exposure time is sufficiently quick to minimise its effects. Equally, at longer whole second exposures, the duration of the vibration is too short lived to be significant. I would intuitively suggest that the danger zone starts at around 1/30th of a second (depending on the camera). For the sake of argument, say mirror slap vibration last for 1/60th of a second. At a shutter speed of 1/30th that's 50% of the exposure time, but at 1/15th it's down to 25%, at 1/8th it's 12.5%, and so on. If a mirror lock-up is beneficial, it should be most effective at larger fractional times (maybe down to 1/125th or more), not long whole seconds exposures.

Let's not forget that shutter shock also causes vibration, so it makes more sense that manufacturers should focus effort on dampening the moving parts rather than installing devices to preventing the mirror from moving (which would be like Ford including wheel chocks to supplement a poorly performing parking brake!)

Here's an interesting article entitled Mirror lock-up is a conspiracy which draws the conclusion - Mirror Lockup makes absolutely zero visible difference in the sharpness of the photo IF you shoot from a rock solid tripod and ballhead.

I agree with this viewpoint: a mirror lock-up is a poor substitute for a tripod and cable release, and these are things that should be used when shutter speed times fall below that which we can easily hand-hold. Camera shake is always far more of an issue than mirror slap.

Minolta SR-T 101

Minolta SR-T 101

Minolta SR-T 101