New old Minoltas

Here are a few pictures of and comments about the recent acquisitions I mentioned in my last short blog.

To start with, the black SR-1 (d) complete with its correct lens (with the black rear ring on the mount). Nice condition but needs ‘a bit of work’: The first curtain runs fine but the second does not follow… and the mirror stays in the up position. Cock the shutter, the mirror drops and the same happens again.


Then another back one, this time the Japanese market XE, fitted with a contemporary lens, which works fine and accurately. Will get a clean inside and out and then run a test-film:

Then there was this 1949 Minolta-35 model D that I came across, one of about 1,900 made. OK, so I bought a Rather nice later 50mm 2.0 lens (about 1954 manufacture) to use with it, please forgive me. I’ll keep a lookout for the ‘correct’ 45mm 2.8, but in the meantime this will do nicely for my test shots to check the accuracy of the shutter. The third picture shows the small piece of the leatherette covering that is missing, which is invisible inside the case, which I will initially be making myself, especially in view of the larger lens 🙂

Minolta produced the earliest cameras with a central ’hot’ flash-contact in the shoe (introduced on the first -35 model A). They interestingly replaced it with a cable-connector on the next, ‘E’ model of the Series and with a coax connection à la Leitz on the model ‘F’. The ‘D’ model is purportedly the first with flash synchronisation (for bulb flash only, electronic flash synchronisation was first added to the Minolta-35 model II) but I find that hard to believe. Canon only offered Flash synch two years later in 1951 with their Canon IV.

Plenty going on

At the moment there is too much going on all at once… We are moving in the next month to Spenge in NRW, as a result of my having work there with a previous employer – for more money. OK, there won’t be more left over (rent is higher), but everything else is altogether more convenient and closer to three of my four children 🙂

On the camera front, my Minolta-35 D model turned up and is having a good looking at at present, still waiting for the lens and I’ll be picking up a black SR-1 (b) and a nice black XE, too in the next few days, photos to follow, not sure when – beginning to pack in between working, eating and sleeping!

Removing the top of an SR- camera safely

The whole SR series of cameras from Minolta are similar in their construction. The only departure from the theme would be the SR-7, which has an in-built light meter and battery, but the basic principle is actually valid for almost any mechanical SLR (with notable exceptions, of course, like cameras with removable finders).

I have prepared a short video to show how it can be easily and safely done without doing any damage to camera or yourself. What you do afterwards I can take no responsibility for. I only need to access inside the top to clean the prism faces and check the cleanliness of the film-winding mechanics. In the case of a stuck camera, 99% can be done just by removing the BASE plate and adjustment or cleaning of the slow-gears are inside the mirror-box, as previously described.

Here is a link to the video, while I try to resolve the uploading problem that I now seem to have…

https://www.dropbox.com/s/wezkvi41sao6h2z/Video%2006-12-2019%2C%2014%2043%2017%20Copy.mp4?dl=0

The video will soon be uploaded, but first I have to do a light edit to remove my head from blocking the view… 🙂

Interesting for those that have never looked inside one of these, there are internal differences even between early and later versions of the SR-2, as demonstrated here!

This is an early model (1100783) and just look at this! The inside of the top pressing has been hand painted in black on the inside

Before wiping off, there is a little mould on the prism (corners masked off with black insulating tape) and the holding mechanism for the prism is very different to the ‘later’ models (as of when?) Clamped at the back and sides instead of the customary overslung bracket and springs, over a plastic moulding protecting the prism. (See below, both are SR-2s – the one on the right has the film transport partially dismantled)

The yellow arrows show the screws on the brackets to remove them, the red outlines the brackets somewhat…

This is the one that is accessible on the left – the one on the other side is not! This one only needs to be loosened.

Once having removed the screws and brackets, the prism has to be lifted about ⅛” or 3mm upwards to release it. Here is mine and, though not really very visible here, the specs that you can see are  fungus ‘spiders’ settled and spreading on the prism… easily removed with a 3%-10% peroxide solution applied with a soft artists’ paintbrush and a quick wipe-off – no costly coatings to worry about here, anyway! 🙂

Minolta RF Rokkor 500mm f8 sunshade

Well, I don’t know about you, but the pitiful length of the sunshade on both mirror lenses I have owned have always disappointed me… I realise that the coatings on these lenses are nothing short of wonderful, but especially mirror lenses are very sensitive not only to vibration, but also to adverse light conditions. So I thought I’d do a test. I made up a sunshade out of card and tested how far I could go without vignetting on the 500mm shown here. Believe me, I was surprised! The whole inch of the original sunshade was well under a sixth of the shade I built WITHOUT any sign of vignetting. I don’t think that anything shorter than the diameter of the front lens is useful or that anything much longer has any actual added benefit (I’m willing to be corrected on this), so I decided to improvise myself and use ‘easily available resources’ (i.e. without resource to a lathe) to make a usable and effective sunshade. Originally a little tongue-in-cheek, the finished product works wonderfully, was really cheap to make and is light and can store all sorts of stuff – even a lens – inside it in the camera-bag! Win-Win 🙂

The diameter of the lens makes it unusual, so getting one from another lens was out of the question. Looking around the house, I found a consumables tin that fit actually very nicely and also had he benefit of a plastic lid that would be handy as a lens cap! Originally filled with nuts bought from a supermarket (the same size is currently available here for the equivalent of £2.50), I carefully removed the bottom with a cutter and pressed/rolled the ragged inside edges flat with a cross-head screwdriver blade (anything metal or hardwood would do the trick) and put some ‘zebra’ tape (paper, actually) on the inside to stop it scratching the paint on my beloved lens… 🙂 At this stage, the functional work has been done, as it now slide-fits snugly over the front of the lens including the original sunshade and butts up nicely against the barrel, without being loose. I then decided that rather than spraying it matte black on the inside, that I would line it with black rubber foam sheet available at almost all supermarkets in their craft department in various colours. A strip 44mm wide is perfect, as it fits exactly from the front to where the original sunshade is and gives extra ‘Register’ there, to hold it nice and snug.
Look at the photos to convince yourselves of the fit and function – regarding the optics of the outside, perhaps you will decide for yourselves what is more appropriate. I went for a cover of thin, black leather, but matte black spray paint, card or anything else will do according to your taste; you could even leave it as it is (as I have for months!) or do a pink fur and Smarotzi-Diamond job on it! Enjoy!


To be honest, even the Original cap fits (as seen on the photo above), but the original for the tin is of course a perfect fit.

You May also have spotted another ‘modification’ that I have for this lens to take the light input down a stop, without having to swap filters in the back! I converted it to an f11 lens with a ring of the same foam rubber sheet as above (formerly tested with black card) which is cut to fit nicely under its own tension in the front of the lens. No glue, just fits nicely and doesn’t fall out an can so easily be removed or replaced, doesn’t get damaged or damage anything and doesn’t take up any space either! The doughnut-ring Bokeh ist thinner, of course, but for a quick and dirty solution, this works nicely. I can’t claim that the depth-of-field is influenced to any degree, though. Still, it does offer a bit more than just one ND4 in a pinch!

The case on the Sony is also one of my handmade additions, too, by the way. The top will be completed soon, too!

Here is the budget sunshade as finished and used at present: I could have used black thread, but, “what the hell”, I thought… 🙂

Dr. Peter is a frequent contributor to thingummybob.com

Minolta SR Slow Speed governor checkup

Hallo SR Fans! Ever wondered where the slow speeds (less than 1/15th) are clockworked? Like most other mechanical movements that are past their ‘sell-by-date’ (in this case nearly 60 years out of guarantee!), the works are often glued up or just plain sticky. The oils and greases after so long turn to sticky goo and don’t do the intended job anymore.

With this particular camera, as with many others, a good clean with lighter fuel is all that is needed to keep things running smoothly for many years to come without any lubrication. Let’s face it, how often do you use shutter speeds of ⅛ or less in general – or the self-timer, for that matter, unless you are needing the slow speeds, of course… For macro work, for example?

Nevertheless, it is annoying when they don’t work on an otherwise usable camera, so here is a quick fix for those who are interested:

The clockwork for the low-speeds are under this cover; hold the mirror up and be careful when undoing the screws, as they are not very ‘deep’ and you are going at them at an angle, because the prism housing and lens-mount are sort of in the way 🙂 The paint scratches easily and you don’t want anything bright or reflective in there!

This is what it looks like under the cover and is where the buzzing comes from:

Upright the camera when rinsing out with lighter-fuel (as in this pic), please and then cock the shutter and release a few times at each speed, until it sounds right. Don’t be be tempted to add oil, it really isn’t necessary. Any traces of old oil will pool where it is needed through capillary action and be left when the fuel evaporates. If it sticks again in ten or twenty years, you now know where to fix it! 🙂

l recently received an SR-2 that behaved strangely: The shutter seemed oddly stuck, but somehow released, but left the mirror up… One shutter blind worked, but the other just stayed put. What was the problem? When I took the front plate off, I found the shutter blind completely wrapped and stuck to itself. Melted, actually! Some over-zealous previous owner had diligently removed the top cover and ‘cleaned’ the works by pouring acetone over it… No problem for the metal parts, but what dropped through onto the roller-blind fused it together for keeps! So, please remember, use a fine artist’s brush to apply fuel/cleaner or a very thin Pipette, so that you can control where it goes 🙂

This is what greeted me inside:

Minolta SR-2 vs SR-1 comparison

Ever wondered what the real internal differences are between Minolta‘s first SLRs? First pic is of an SR-2 stripped of the ‘leather’, top and bottom plates off and my high-tech protection for the mirror box internals. The front plate with the mount and self-timer has not yet been removed.

SR-1 partially dismantled, but with the front mount section already off and the self-timer no longer fitted. Notice the difference between the castings and the ‘SRC’ in relief on the front next the mount: on the SR-2 there is not any such marking.

Here I’ll give a short look inside to still your curiosity (and mine!). So the SR-2 was the first in late 1958 and is put next to an SR-1 from around 1961, the ‘c’-version; the last one before the change was made to the aperture automatic. Two quite different mechanicals altogether, despite looking very similar, especially the bottom end, where the aperture and shutter actuation takes place.

Optically, the early and later models are relatively easy to tell apart if you know what to look for.. all the 1959 models have a much smaller eyepiece on the back, which is not so easy to spot at a glance. Easier to notice is the shutter-speed knob on the really early ones (the SR-1, too) that needed to be lifted to change the shutter-speed. On the top the scale is not quite evenly distributed, the 250, 500 and 1000 look evenly spaced, but they do have a little white line engraved to show the actual position needed to dial in those three speeds. From the front, the early dial is more conical in shape, wider at the bottom and smaller in diameter on the top than the later model (there is about a 2mm gap to the winder-lever). The later one, as you can see, is more straight from the side, and is as a result larger on top and has evenly spaced engravings up to 500, without the extra lines. The earliest SR-1 shutter-speed dial was similar in shape and size to the SE-2, missing the top speed, of course. There follows a series of photos showing some of the the external and the internal differences. Later I will show the internals of the first SR-1 model, but the differences between these two models are more obvious 🙂 The picture below shows the SRC on the casting rather more plainly.

There are, of course, lots of detail differences, that are too many to mention here, but worth mentioning and visible in this shot, is the mirror-fixing with screws, rather than the riveted-on mirror in the SR-2 🙂 There are also subtle differences between the self-timers, not only the front casting which they are mounted to: The one on the bottom or the right in this picture is off the SR-2 and fits behind the oblong brass plate. It also has an extra large flat screw (taken off on this picture below, but visible later once mounted) on the front side and the teeth on the spring-gear (the largest one) look like they have been ground or worn down… look closely at the pictures and you will see what I mean! The difference in the gear is plain to see.

SR-2 with the sellotape and here the differences in the gear-teeth are more obvious on this one. Note also that the backing plates are not the same, though the mechanisms are largely interchangeable:

Here the SR-2 self-timer is fitted and the large screw which is no longer on the later models at the front is rather obvious. The screw behind it on later ones is also significantly thicker (see pictures above).


Below shows the shutter-release mechanism in the base which is distributed half-half between topside and bottom. Most jamming can/must be sorted down here, the shutter speeds are controlled on topside. The lead-wires are for the flash synch and every camera seems to have them differently routed, depending on the wishes of the assembler! Here the difference in the size and shape of the tripod-mount is also visible, along with the completely different mechanical layout… few interchangeable parts here!

A look at the base plates shows that both are also different, as the mechanism on the SR-1 needs a cut-out at front (behind the lens-mount) to accommodate it – in preparation for the following model. At this stage, they both still have the long-travel aperture lever. the hole for the tripod-thread is also larger on the baseplate of the later body.

Well, that wraps it up for today. I will sort out the orientation of the pictures when I get home… I wrote this on my phone and it won’t let me do everything I want to!

Early Minolta Auto Rokkor-QE 1:3.5 f=100mm comparison

How interesting it is to get two lenses like this next to one another to compare, made only a few years apart. The two in question are probably the most underestimated in Minolta’s lineup for very many years and still perform very well even against modern lenses at 43MP… These are just as sharp, if not better, certainly in the edge resolution than the 2.5 and the 100mm 2.0 that is in high demand (only because it is rare, not for its performance).  I might  go into that in more detail later, around when I release a test of the 24mm VFC 2.8, how to use it to do what it does, what VFC is actually useful for and some ideas about lens-testing methods in general, including inherent non-flat focus field (curvature) in lenses in general – which is always taken as given.

So, to start off with, looking at the fronts, I have two 100mm, 3.5 lenses from Minolta, built only a few years apart. The early one, an ARI, ser 1201946. Looking at many lenses, I might conclude that this is a lens of series code 12, number 01946 produced? There are many theories about the Minolta serial numbers and any of them could be right or wrong in the absence of any proof 🙂 Made somewhere in 1959-60. Whatever, the front engraving is as expected. The second one, an ARII with the serial 1213805  is missing the expected ‘Lens made in Japan’ engraving on the front, so is one of the earlier ones of this series produced.

If you look closely, you will also see that the front lens is more deeply recessed into the front on the later model.

Now turning to the back, we can see more differences: ARI-typical closed ring and screwed-on aperture link, ARII-typical linkage poking out of a slot in the back and, of course the stop-down lever now necessary after the automatic diaphragm was introduced on the SR-1 (4th model) and the second run of the SR-3, meaning that after the exposure, the aperture opened immediately. Yes, the knurled ring is missing on the stop-down lever, but will be added when I get one in 🙂

Also note the relative position of the rear lens elements, both focussed at infinity in this picture.

Here shown at an angle to emphasise the differences between the two, the ARI sits considerably deeper, which makes me wonder about them being the same formula for lenses and groupings…

Now both are focussed as close as can be done, 1.2m and 4ft, ARI Stil much deeper.

Interesting how both are so different internally, obvious from the back. Look how the shrouding goes right in to cover the full depth of the travel of the rear element here on the ARII…

… Whereby here the thread of the focus ring is exposed when wound to close-focus!

Now take a look at the difference in size between them: First the length is obvious. The added length of the later one (here on the left) seems to have mostly been added on to the front of the focus-ring :). Just also take note of the difference in the thickness of the focus-ring (which is why there is a bigger step in the front of the barrel of the earlier lens).

Here the nice even engravings are obvious (except for the ‘4’ on the ARI, missing on the later one altogether) as are the absence of engraved dots indicating half-stop clicks. Nice unblemished ‘Minolta green’ on the ft. engravings!

Same again at infinity, same difference in length (3mm)

Now the other side and here the white ‘Lens made in Japan’ on the ARII  and the simple ‘Japan’ in black on the early lens.

The big change for the ARII was not only the rear actuation of the aperture but in the iris itself, which had to be lighter and better balanced to react quickly to shut down and reopen adequately for the new shutter action on the now modernised cameras. Take a look down the barrel and the differences are obvious in the different shape of the iris itself. Still 8 blades, but very differently arranged, ‘back to front’, so to speak.

At f8 both look pretty much the same, though the earlier one is just a tad ’rounder’, but not enough to make any difference to the bokeh.

One surprise yet, is that the earlier, shorter by 3mm and narrower by 2mm in diameter lens, is heavier (402g against 382g) than the later one! Remember the difference in the thickness of the focussing-ring-casting?

The extra overall diameter of the later lens does have one potentially slightly annoying drawback… The DK57KD lenshood designed for it no longer fits on the lens backwards as it did on the early lens, so extra storage has to be found for it. Not really anything in the least important, but nonetheless worth mentioning.

Next up? Not sure yet, as I go into hospital on Tuesday to operate on my right shoulder again 🙁 I also have to make sure that the car is back on its wheels by then…

Minolta AES Viewfinder repair

A Minolta AES viewfinder, rather desirable if not so dented! If it were only the dent, that would not be so bad, but usually other things have also suffered as a result of the bash that caused the dent in the first place. Let’s have a closer look ‘under the bonnet’…

OK, this kind of space is all you need, so there is no excuse for not having a go yourself! Yes, I could have cleaned up before the photo, but it just goes to show the general arrangement. There are tools and materials for all sorts of tinkering and yes, while I’m actually working, there is more space around the working area as such.

So, having taken the top off (easily enough done on this) it can be seen that the dent wasn’t all that was wrong: the mirror and lens which allow the numbers on the aperture-ring to show in the finder are gone! The thin red outline shows the aperture-link in the ‘normal’ position without a lens in place – more of that in a minute.

Here a clearer view from the top and at the back, the long mirror for the shutter-speed display is also missing, but thankfully had dropped inside and could be reduced in its proper place 🙂

Here even more obvious, the REASON for what it missing and how it lines up with the lens ring. All I needed was to find a mirror and lens in my goodies-box and the case was solved. If I’m honest, a piece of 1mm thick polished Stainless would replace any missing mirror if you don’t have an original handy (the mirroring on these is on the FRONT surface, not on the back like a household mirror). For the lens, any one cut out of another Minolta SLR will do, even if you do have to trim it to size, it will do the same job since the distances of all finders from the lens-ring are very similar.

Below is a very different problem which afflicts almost every Minolta AES and AE viewfinder (not the others, since they don’t have metering). When the finder is removed, before replacing it the aperture ring follower has to be ‘cocked’, so that it snaps into the right place, should a lens be on the camera (in use that would be the norm). However, these cameras are a few years old now and have gone through the hands of many people, some salespersons, some of them photographers, some of them collectors and some of them without any knowledge of the workings of such things, from any of the above. This design was intended to save the camera being damaged by replacing the viewfinder with force and perhaps bending the linkages in the process. If you try to replace it ‘just like that’, you will notice that it doesn’t sit quite right at the front. Unfortunately, the uninitiated will just press harder until it clicks in place – the result of which can be seen below! The arrow on the right shows the follower correctly cocked on the right hand side and in the middle the release lever to reset it.

See the flat on the release lever? That comes from pushing the viewfinder down at the front until it clicks into place, as this lever, when the follower is not cocked, protrudes a bit as a reminder… of cocked properly, it retracts out of the way, of course.

So, who cares if it has a flat on it? Well, the user, actually, because having read the handbook and having cocked the lever properly, when the viewfinder goes back on, the follower doesn’t return to it’s proper place again and the metering is all haywire as a result!

The cure is to build up the front of the camera-frame, where the lever ‘lands’ with a strip of tape or whatever you have handy that it just thick enough to ‘trip’ the lever and something that does not permanently fix to the camera or damage it. Here I took a strip of cardboard and some insulating tape to fix it. It’s cheap and easy, works fine and doesn’t do any damage. Win-win! Don’t worry about light-leaks up here, the well is deep enough to shield any light that might come in – don’t forget, the eyepiece lets a lot more light into the prism.

Just a reminder of how the top looked like before. Suffice to say, I did a bit of persuasion with an appropriate piece of wood and repaired the dent without needing any touching up of the paint, which sticks like shit to an army blanket (ask anyone who has ever been a soldier).

You can’t see it here, but once the mirrors etc. have been replaced, the next step is re-assembly, which is pretty straightforward. Working from right to left in reverse order of disassembly.

 

 

 

 

Finally assembled with ISO 160 showing here and ready to go! All adjustments and cross-checks of the mechanics and metering were also done while the lid was off, of course.

The repair to the top is acceptable, I think.

Next up for discussion? The comparison of two very early 100mm F3.5 lenses an AR1 and an AR2 (by the way, one of Minoltas best-kept secrets, an inexplicably underrated razor-sharp lens). Construction, mount, iris, size and weight are different… Though they look very similar, until you have them up close 🙂

 

P-39 Airacobra Restoration

For those interested in Aviation, warbirds and the modelling of the aforementioned, here are a few pictures I took while working on the Airacobra in Australia at the ‘Classic Jets’ Museum at Parafield Airport in South Australia. Actually the busiest airport in the whole of Australia, mainly due to it’s being the home of a number of flying schools, including one used for flight training of quite a few large airlines, Parafield is also home to a number of classic ‘fly-ins’ and the Museum, of course, where almost all the work is done by volunteers. I worked on a few aircraft, but this is the one I spent most time working on.

Here a couple of views inside the workshop hangar.

Gives a general idea of things. The RAAF Airacobra in question in the background. Here are a few pics of the instruments and cockpit as it goes together:

And here a closer view of few of some of the individual instruments:

 

Lots of engine-details for the modelling enthusiast. These pictures are big, just click on them for larger, click again for super-size! Not much chance to see one of these up close, though used for many aircraft. Carburettor at the top and induction charger below it, the (shiny!) induction manifold on the top of the engine between the ‘V’. The pic on the top left shows it in the initial stages of build. As we progress it gets ‘smarter’ 🙂

  

The pictures below are of the other, running, engine in the public hangar which was originally out of a P40, which is why it has the reduction gear on the front, unlike the P39, which had it installed just behing the propeller and spinner, of course, fed by the propshaft which ran between the pilot;s legs… Makes quite a racket in the hangar and we converted it to run on Gas, as when on Avgas, the open carburettor spat flames to the roof on a cold start… 🙂

Here a few official pictures of the engine from Allinson themselves:

   

 

Here some detail pictures of the armament and ammo-boxes being built for up front. Ours didn’t have guns in the wings. Two machine-guns synchronised through the prop and a cannon shooting through the centre of the spinner. Convenient that the reduction gearbox, mounted on the front-most bulkhead had a hollow spindle! Drive from the prop-shaft enters at the bottom of the reduction-gear casting and the actual drive to the prop is a larger gear above it, allowing plenty of space for the ‘shooter’.

The rearmost, larger but narrower, munitions-boxes are for the machine-guns, the wider curved rails are for the larger (and fewer) cannon-shells:

Here how it is set up in the ‘plane still in primer:

 

Not in primer anymore and fitted up in TG*R !

And finally finished and mounted : (this one in Victoria, another A/C, another museum) The red box is a battery! More weight up front, critical for the distribution of weight and balance necessary to fly the aircraft. The mid-engine made it more maneuverable, but more sensitive to weight distribution. Cannon-shells fitted, MC Ammo-boxes not yet.

Here a few pics of some work I did on a pair of rearmost wing-fillets. We had one original on loan to copy and I had to make up left and right copies, hence the reversible template. The finished items were made slightly large all round for final ‘fitting’:

 

Here the aircraft ready and finished for the Parafield Airport Vintage Fly-In in 2009

Minolta SR lenses NOT the same as MC/MD

OK, So everywhere we see the ads, mostly on eBay, where Minolta SR lenses (the ones called Auto Rokkor, with ‘W’ for wide or ‘Tele’ added on) are broadly equated to MD-Fit or something similar. Beware! This is not necessarily so!  The very early lenses do FIT ON the Minolta Bayonet, but DO NOT STOP DOWN to their minimum aperture. This has physical reasons, which I shall explain.

This means that the first series of these lenses attach correctly (the Minolta bayonet stayed the same until Auto-Focus came along) BUT the lenses only stop down on the later cameras to an aperture of around f8, no matter what you pre-set on the lens. This is due to the placement of the lever inside the cameras and lenses, that are, to put it simply, in different places! From f8 upwards in the direction of ‘more open’ I have found no limits and the restriction does NOT apply to fitting to Digital cameras with adapters that anyway don’t stop down, which is great news.

Take a look why: I have taken shots of an early SR1 (‘b’ series) from 1960 and compared it to the mount on the SRT* (in this case a 303) when the ‘MC’ notation was introduced. Note the placement of the lever at the bottom of the mount, that closes the lens down at exposure.

Firstly here, the back of an SRT/MC/MD Mount lens on the left compared with the early SR (Auto Rokkor without the MC/MD) mount lens on the right. You will note the difference in the placement of the Iris-Lever, although both are stopped down to f22. What you can’t see, is the range of travel of the lever for the lens on the right, which is almost the whole arc as drawn in. compared to the tiddly bit which is obvious in comparison on the left lens (physically limited by the slot it can move in axially – less than half of the arc); on the later Auto Rokkor lenses, from about 1960, the stop-down lever for the iris is the same as for the MC lenses operating from inside a ‘window’ and will work perfectly on later cameras – definitely any camera made after 1961.

Below the positions of the actuating levers inside the back of the mount on the cameras themselves can be seen. The SRT 303 is representative in its proportions of ALL manual Minolta mounts from then up until the introduction of the Auto Focus mount.

In this picture, the lens would be STOPPED DOWN, on the SRT using the button on the side of the mount and on this early SR (1959) by simply not cocking the shutter – fully automatic diaphragm came in 1961 when both the SR3 and SR1 got the modification. The difference in the position at maximum deflection is pretty obvious.

The same two cameras when the aperture is held open: Actually identical.

Here we have both cameras with the lens mounted and stopped down to f22. I think the difference speaks for itself. The picture speaks a thousand words?

The SRT manages just smaller than f8. This will happen to ALL early Auto Rokkor lenses if mounted on SRT and later cameras (actually any Minolta after at the latest 1961, when the automatic diaphragm was introduced). The other way around, ANY Manual lens will work correctly on the earlier, pre-SRT cameras and of course with any of the Digitals, too – with an adapter.

So, it’s up to you, but buying the earlier lenses, with very few exceptions, is not better than a comparable MC or MD, despite being cheaper (mostly). Quite apart from the mentioned deficit in the usability on later cameras, for the most part the performance and definitely the coatings just doesn’t make it worthwhile – unless you have the very much earlier cameras! The thing to look out for to positively identify the first series of lenses is the flat ring on the back of the lens without the ‘window’ for the iris-coupling, as clearly shown in the pictures above. Another indicator, if not definitive, is the aperture-ring with the engraved yellow ‘LV’ values below the f-numbers. Some, however, even with these engravings also had the later mechanism 🙂 The thing to look for is the evenness of the aperture engravings (if they look ‘wonky’ then they probably have the long travel) and the back of the lens, of course. If the pin sticks out of a narrow window, then you are fine. Watch out for lenses over 100mm, they might be long-travel AND have a window for the pin: the length of the window will give it away.

The SR-2 and both ‘a’ (first series with ‘lift-up’ shutter-speed dial) and ‘b’ versions of the SR-1 without the meter block all have the long-travel lever, but in 1960 alongside the introduction of the SR-3, there was also a ‘plain’ SR-1 (‘c’) without the block, but with the automatic diaphragm…