Minolta was founded in 1928 as “Nichi-Doku Shashinki Shōten” (Japanese-German camera shop). After a line of rangefinder cameras modeled close to Leicas the company introduced it's first SLR camera in 1958, the SR-2 with the first Japanese bayonet mount. I'm referring to manual lenses from Minolta for this mount only, officially called SR, but most call it MC/MD these days. MC lenses (meter coupled) are the older ones, produced from 1966, but the only difference in MD mount from 1977 is a modified mechanical coupling for the aperture setting in the MD. The mount stayed compatible between all lenses until the very first autofocus camera was introduced by Minolta in 1985. Of course they continued to make some lenses for the older mount for quite a while after 1985. All lenses with this mount can be adapted to modern mirrorless cameras like µFT or NEX, but via an adapter from MD/MC to Leica-M you can mount it on RED's Leica-M mount just fine. None of these lenses expands beyond the mount, so there is no problem with this combination like there is with most Leica-M lenses wider than 50mm.
After trying to copy Leica all the time from 1958, they learned to do it so well that in 1972, they sub-contracted with Leica and drew up a formal cooperation agreement. “Leitz desperately needed expertise in camera body electronics, and Minolta felt that they could learn from Leitz's undoubted optical expertise.” (source: Wikipedia) Many of their lenses carry the name “Rokkor” (after the mountain Rokko near to their factory in Japan). In the US most were called Rokkor-X without being any different from the plain Rokkors sold elsewhere. In later years a budget line of lenses (called Celtic in the US) was introduced. Between 1979 and 1982 Minolta redesigned many lenses for lighter and more compact versions with a 49mm filter thread, using some plastics instead of metal. IMHO the older, heavier and more massive ones with a 55mm filter thread are the better built lenses. If treated well, focus and aperture are working as smooth as on the first day even after 40 years or more.
The optical quality of some of the redesigned ones from this period can be better, though (I'll get back to this when getting to individual lenses), and it was not before 1982 that even more plastic was used and cost reduction became an important factor for most of the lenses targeted at amateur markets. Apart from some very special, earlier gems the lenses from early to mid eighties can be recommended for being the best in coating and build. Starting from mid nineties pressure from third-party manufacturers started a massive decline in overall quality and increased sample variation – until then Minolta had pretty tight QC.
*The best index to identify a Minolta lens and it's age can be found here:*
http://minolta.eazypix.de/lenses/index.html
Watch out: some lenses can have significant differences in their optical design and quality (the 135mm tele for example) and are only identified by their precise weight and size. A two letter signature was only used for MC lenses and designated the number of lenses and groups in the particular lens.
The system goes like this:
Accordingly, the famous 58mm 1:1.2 MC Rokkor PG contains 7 elements in 5 groups.
Although there is no official explanation, it is easy to see the greek alphabet in the first code letter designating groups, Penta, Hexa, Septa, Okta, etc.
The second letter is probably just chosen by alphabetical order. Via http://minolta.rokkor.de/minoltalenses.htm
All classical lenses (without digital correction in camera bodies) are a complex optimization of different parameters, some of which can be contradictory. Minolta had a philosophy of not favoring only one parameter (like MTF) on the cost of another, like quality of bokeh (which was discussed among aficionados in Japan much earlier than elsewhere). Most important – in particular for us as filmmakers – is the consistency of color and contrast over the whole line of lenses Minolta was striving for by making their own glass and carefully balancing it's color with their coatings. Just like others, they improved coatings over the years and younger versions are in general less flare-prone than older ones, but they always maintained the Minolta look.
Leica (from whom Minolta learned a lot about optics) has never achieved such a level of consistency, they tried to make every single lens as good as possible – with remarkable results. But Summicrons for still cameras with a different number of elements can have quite different color and contrast (I'm not talking about their cine lenses here). Apart from that, the Minolta look is closer to Leica than Zeiss, which are also quite consistent in color (but not always for contrast) in lines like Hasselblad and Contax, just different. That's why I have quite a few of both Rokkors and Contax Zeiss lenses, while I don't have any Leica lenses. Some call Minolta lenses “poor man's Leicas” for a reason 
Film emulsion is not as reflective as the OLPF of a digital camera. This simple fact can make a big difference when older still lenses are used on digital sensors, since the manufacturers didn't put as much effort into the coating of the rear surfaces as today. You may see haloing if using fast lenses on a digital camera wide open. That said, I found a Nikkor 50mm 1.4 for example much weaker in this respect than a MC Rokkor PG 50mm 1.4 from the same era. This Rokkor, BTW, is one of the sharpest 50mm lenses I've ever tested, bested only by the Zeiss C/Y 50mm 1.7 (but not the 1.4!). The effect can be very different from lens to lens, it depends very much on the curvature of the back lens. Apart from this contrast reducing effect, these lenses are just as good on digital as on film. All wides are retro-focus constructions; being designed for SLRs, they don't expose the side effects some rangefinder lenses can show in the corners due to extreme angles of the light rays.
The most sought after (and accordingly pricey) lenses are the 85mm 2.8 Varisoft, the 24mm 2.8 VFC and the 35mm 2.8 Shift CA lens. The Varisoft is a specialized portrait lens whose spherical aberration correction can be adjusted between a very sharp image with rather nervous bokeh and a very dreamy look like from a fashion magazine of the sixties (similar, but not quite the same as the expensive Nikkor DC = Defocus Control). The VFC (Variable Field Curvature) lens is a very good wide at neutral, but it's field of focus can be adjusted to be concave or convex. Obviously, the effect is not as strong on a RED as on photographic full-frame. The Shift CA has a similar VFC adjustment plus a very precise shifting mechanism and if you've ever asked yourself, how you can shoot a CU as if looking straight into a mirror without being seen: here you go! Initially it was meant for architecture to avoid too much perspective inclination of vertical lines. A mechanical masterpiece.
Over the next few posts I'm going to introduce a few other, more daily work favorites of mine.
Until then, there is a lot of information in English here: http://www.rokkorfiles.com and here: http://digitalrokkor.altervista.org/minoltalens.html (scroll down for English)
and some in German:
Let me first make it clear that I don't like to comment on lenses I never tried. I'm not a fan of fisheyes so I didn't try the 16mm 2.8 fisheye, but others gave it very good reviews and even the new AF versions still use the same optical formula. It was also sold by Leica as an Elmarit-R lens.
I once tried the 17mm 4.0, but I wasn't overwhelmed. It seems that this construction was a bit beyond of what could be done well at the time. Even with it's slow f4, you need to stop it down: at least one stop, rather two, to get decent corners, both in sharpness and vignetting. Plus, it has quite annoying 'moustache' distortion. I'd say it isn't worth to be hunt down (it's pretty rare).
The first one up that is worth considering is the 21mm 2.8, it's the best of the 20/21mm range Minolta made over time. The full name of my favorite is MC W.ROKKOR NL, so it's a very complex construction with 12 lenses in 9 groups. I consider it even a tad better than it's successor, the 20mm MD Rokkor 2.8. It's one of the first constructions by Minolta with floating elements, this is a massive piece of metal and glass with a MFD of 25cm. The front lens is rotating when focussing, but not the filter thread – no problems with screw-on polarizers. It's one of the few Rokkors with a 72mm filter thread instead of 55mm. It is sharp and has pretty low vignetting or distortion even wide open. I'd say it's second only to the Zeiss Distagon 21mm 2.8, which is pretty hard to find and very expensive. You'll need some patience to find the Rokkor, but it comes much cheaper than the Zeiss.
The 24mm 2.8 is much easier to find, you won't need the rare VFC version I mentioned above to get excellent optical quality. It was sold under the Leica brand too, but be sure to get the 9 lenses version. Stay away from the late, smaller version with a 49mm filter thread and 8 lenses, all others are simply great. Tack sharp even wide open, low distortion, you name it. I consider this lens even better than the Zeiss Contax 25mm 2.8 (by a narrow margin, this is one of the weakest lenses in the C/Y mount). BTW: the Kiron 24mm 2.0, which is getting hyped quite bit, can't compete even stopped down to 2.8 – I tried it.
The MD W Rokkor 28mm 2.0 is another great lens, but harder to find than the 2.8. (MFD is 30cm). Stopped down to 2.8 it is in every aspect as good or better compared to the 28mm 2.8. I sold my 2.8 once I got a 2.0 in good condition. You can't say this about all other lenses, in the Zeiss Contax line for example the 28mm 2.0 is not as good as the 28mm 2.8, even if stopped down to the same value. The Contax (nicknamed Hollywood) is very good, nevertheless, but far more expensive than the Rokkor. The 28mm 2.8 is no lemon at all, and it can still be found pretty cheap. Don't buy the late 5/5 lens version, though, the earlier 7/7 construction is heavier, but better.
Let's get to 35mm, even if we might not call this length 'wide' any more on GH-2. The MC W.Rokkor-HG 1:2,8/35 has a problem with oil on the blades quite frequently. So rather go for the later MD versions this time, the optical quality is very close, the coating even better. The Shift CA Rokkor 35mm mentioned above is a very special lens, but hard to find. A true gem is the MC W.Rokkor 35 1.8, just like it's MD version. I like the bokeh of this lens better than that of the 35mm 2.8, OTOH the 2.8 is tack sharp too, just has a bit harsher bokeh. At 2.8 both lenses show about the same level of quality, so you can save money if you buy the 2.8.
To bridge the gap to standard length, let's continue with two small zooms, the 24-50mm 4.0 and the 35-70mm 3.5. Both are two-touch and parfocal – just the right thing for us. They even offer the third important feature for cine: constant aperture! A masterpiece of mechanical construction, the aperture is closing or opening slightly together with the zoom in use.
If you couple FF gear with the zoom ring, they can deliver a beautiful, very soft push-in or creep-out. These are not todays super zooms with impressive range, but crappy quality like many zooms for the amateur market – these are professional. The wider one is fighting a bit at 24mm with slightly softer corners and some CA vs. it's outstanding 24mm prime counterpart (see above), it's also a bit softer in the corners than the 35 and 50mm primes, but it's not a bad lens at all.
But the 35-70 is a gem, developed for Leica and sold for many years as their Vario-Elmar-R. It is as good as the primes in it's range, and these are very good primes if they are Rokkors. I'd say it's second only to the 35-70mm Zeiss Contax in optical quality, but by a narrow margin. OTOH, the Zeiss C/Y is one-touch. Ouch! (Just my opinion.) It's far cheaper too, don't worry if you get one with a zoom ring that feels a bit loose (longitudinally), that seems to be normal. Circular precision should still be fine. There is a macro version too. I own the one without (got three great macros, I'll describe later), but I've never heard that the one with macro is any worse.
Well, did I say as good as the primes? While there are plenty of 50mm primes like for any other classic SLR, there are two gems I value higher than that zoom. One is the so-called “Bokeh Monster”, the 58mm 1.2, a heavy piece of glass and metal. It is a favorite with Canon shooters, since it's relatively easy to convert this one to EF mount. Accordingly, it's hard to find and pretty expensive. Good resolution and creamy, very “Leica”, but protect it from direct rays with a sunshade. Low-con wide open, but the resolution is there. The older ones with the knurled metal focus ring (instead of rubber) can have stuck aperture blades from oil, but this one is worth a clean. It is also mildly radioactive – nothing to worry about like the infamous Kodak arial lenses – but it can show some yellowing. A longer UV bath will cure this, but the older version is also more sensitive to flare (albeit a pretty flare in my eyes). So, try to get the newer version, it won't show any of these weaknesses and is just as good.
If you don't want to shell out as much, the 58mm 1.4 is still cheap and nearly as good in resolution and bokeh; it seems to be common in the USA. Or try to find a “hidden gem” by looking for innocent offers of just a Minolta SLR camera with a “standard” lens – the 58mm 1.2 came as standard on some expensive models. I found my best one by having a closer look at the picture on Fleabay for the offer of a “Minolta 35mm film camera”. Knowing that Minolta never built one, I had this closer look out of curiosity… So, maybe you are lucky too!
The 50mm 1.4 PG Rokkor is the other extreme, sharp as a knife even WO, very low CA or distortion, but not as creamy in bokeh. This might be one of the sharpest lenses of it's time, tough competition even for the Zeiss C/Y 50mm 1.7 – well, a bit less contrasty wide open, but stopped down I sometimes wonder when looking at charts shot with this lens if I didn't mistake a scan for the photo. An incredible lens for reproduction of small detail.
Well, while we are still at 50mm, there is one lens which is even sharper stopped down: the 50mm 3.5 Macro or the newer, smaller and lighter 50mm 4.0 Macro. It will focus to 23cm (the 50mm 1.4 has a MFD of 50cm), but with an extension tube made specifically for this lens you can get to 1:1 projection on the film plane for 35mm photographic full frame. Point it perpendicular to a magazine page with fine print and high-quality photos, light accordingly and move your scanner to the waste bin! But if you want a macro for nature and living beings, wait till I get to the 100s.
There are three different lines of 85mm Rokkor lenses, all very attractive, but in different ways. The oldest line – starting around 1970 – are the MC/MD 85mm 1.7 lenses. These lenses are beautiful for portrait with a very creamy bokeh, but they offer quite low contrast wide open. This could be intentional, since stopped down to f4 and beyond, they are getting really sharp for landscape – seem's not a bug, but a feature. You need to take care of flare, though. It's very similar in it's characteristics to the 58mm 1.2 mentioned above.
This lens was later replaced by the smaller and lighter MD 85mm 2.0 – a very sharp lens, even WO, with better flare resistance and a bit harsher bokeh. You may see this as a companion to the PG 50mm.
And then there is the 85mm 2.8 Varisoft I already mentioned, a construction patented by Minolta. I suppose Sony now owns the rights to this – one can only hope that they offer something similar again. It is the portrait lens per se, but it can be very sharp too if you leave the softness ring at “0”. Don't get fooled by the harsher bokeh at that position, once you turn the ring to only 0.5, it gets creamy as can be – female talent will love this! Going further, you get very dreamy effects, something difficult to mimick in post or with filters – sharp detail with soft halos. Some old Russian lenses look a bit like this. You need to be lucky to find one in good condition, and it won't come cheap.
100mm 2.5 is next, and another very sharp lens. The bokeh is not unpleasant, so this is another recommendation which can still be found for a good price. Don't bother to hunt down the rare 100mm 2.0 – even if it has a beautiful bokeh, it's the only very fragile construction in the Rokkor line with a focus tube just too thin to survive the test of time (and no other advantages). I've only seen it once, and that specimen was in a pityful condition.
The other very good 100mm is the f3.5 Macro Rokkor. Not only good for Macro, but portrait too, since it has very pretty bokeh and is still sharp. MFD is 45cm, but you can use the extension adapter to get down to 1:1 on FF. Only two disadvantages: flares and is really heavy (but built like a tank). Focus throw is nearly 360 degrees! The 100mm Macro 4.0 is supposed to be more flare resistant and lighter, but I don't own it. This length is much nicer for nature and small animals, since you can keep a reasonable distance. BTW, many Rokkors have a very good focus throw for a still lens, the 58mm for example has more than 180 degrees, the 85mm 2.0 too and the 100mm 2.5 has about 280 – all very smooth even after 40 years!
While we are at macros, I'd like to mention one of the lenses I love dearly, even if it's neither Rokkor nor Zeiss or Russian: the Tamron SP 90mm 2.5 Macro. Beautiful bokeh, very nice for portrait too and still cheap.
The Rokkor 135mm 2.8 is a lens I value very much. The interesting fact about this length is that the simplest construction is the best: try to find the version with 4 separate lenses (aka 4/4), there is one old MC with a 7/5 and one in 6/5 construction, a Celtic in 5/4 and a few MD versions with 5/5 too. They are hard to tell apart, you need the precise weight and length to know which one it is (see the Minolta index in my first post). This is a very sharp lens without vignetting even WO, and you can still find it for peanuts. The other 2.8 versions are not bad either, but the 4/4 version comes very close to the Leica Elmarit-R 135mm 2.8! The 135 2.0 OTOH is very rare, expensive and heavy. The 2.0 needs a larger filter than the rest (72mm) and it is pretty soft and vignettes WO, even at 2.8 it's not as good as the cheaper one. If you don't desperately need the fast lens, save your money. The 2.8 has over 270 degrees of focus throw and a MFD of 1.5m. Oh, BTW, it carries it's own retractable sunshade.
So you may have some money left to spend on the 200mm 4.0
Another great lens which is not too heavy and not too expensive, fully useable WO (if you still call this wide open). MFD is 2.5m, focus throw is over 270 degrees again and it has it's integrated sunshade too. It has a faster sibling, the 200mm 2.8, but that's hard to find and much heavier. Surprisingly not as expensive as the 135mm 2.0 and pretty good optically – I saw one at the bay in the US today going for 250 bucks.
Both of these teles have a nice bokeh and work very well with Minoltas 2x tele-extender S-300 (the S version is recommended up to 200mm). Yes, we all know that such a converter is always a compromise. Unfortunately, all 300mm lenses by Minolta are not as great as the 135 and 200. The 400mm 5.6 APO is supposed to be great, but I don't have it. The only longer one I own is a specialty lens again: the 500mm f8 RF Rokkor – a mirror lens. You know mirror lenses, do you? Well, they have less contrast, a fixed aperture and this funky “donut” bokeh. But my 500mm is shorter than a conventional 200mm, and the full moon doesn't fit into this telescope if I shoot it at 2K Focus throw is about 160 degrees, MFD is as far as 4m and filters are going into the rear end.
So, it can be good fun (for wildlife too) – if you have the right tripod and avoid backgrounds with small, contrasty detail. You can still find it under 200 U$ with some patience, and it's one of the best mirror lenses you can get. The very compact 250mm 5.6 RF mirror lens OTOH is going for insane prices, I suppose all the paparazzi are hunting these unsuspicious tele lenses, since they are not much bigger than a 50mm.
If you buy any RF lens (Minolta made an expensive 800mm f8, a 1000mm f6.3 prototype and even a 1,600mm f11 in very low numbers), make sure you get all the filters and a front cover, they are hard to find if missing. BTW, you'll need a transparent filter in that mount if you don't use ND, since the glass is part of the optical formula. Some more info on mirror lenses is here: http://www.minoltaflashback.com/rf_lens.html
Well, that concludes it, I don't own any of the longer conventional tele lenses neither a tele zoom. The latter are all one touch, which I don't like for cinematography. But the 70-210 f4, nicknamed “beercan” for it's size, is supposed to be some fine glass too. If you have any further questions about the lenses I know, feel free to ask.