This guide will try to give a brief "lay of the land" of what Minolta manual focus cameras and lenses are out there and what will give you the best bang for your buck buying into this extensive but affordable system of cameras and lenses. It is geared towards the budget-minded potential ebay purchaser of a Minolta manual focus camera or lenses who understands some of the basics of aperture, shutter speed and flash. If you don't understand these things, though, you can still benefit from my suggestions of what kits to try to put together for various budgets at the end of the guide. Note that this covers only Minolta manual focus equipment - not the autofocus Minolta Maxxum system, which has a different camera body/lens mount.
The following is a brief and subjective overview of camera bodies. If you want more in-depth info on a particular body, check out the links at the end of the guide.
The X-700 and X-570: The most technologically advanced bodies are the X-700 the X-570. Both offer TTL (through the lens) flash metering (if you use a TTL flash you don't have to calculate what aperture you need; the camera fires the flash and cuts off the flash output when an appropriate ammount of light has returned to a sensor in the body). This is a very handy feature, especially when you bounce your flash off the ceiling or walls and the calculation for what aperture to use is less precise. Both bodies offer aperture priority mode, full manual mode, depth-of-field preview, and the same cloth 1 sec - 1/1000 sec shutter. Only the X-700 offers a program mode, which makes the camera set both the shutter and aperture. I personally never use this mode; you can get better results using aperture priority. The main advantage of the x-570 is that it gives you a metered-manual mode, where the camera displays in the viewfinder both the correct shutter speed and the one you have chosen. The X-700 goes for around $60 for a well listed, tested body (user condition) and the X-570 is about $50.
Some Minolta enthusiasts prefer the XD-11 (XD-7 is the same camera) to the other Minolta bodies. It had a metal shutter curtain (still 1sec to 1/1000 sec) which allowed a 1/100 sec flash sync speed instead of the slower 1/60 sec sync on virtually all the other bodies. It's also got a better build quality (all metal), offers shutter priority exposure as well as metered manual and aperture priority and has depth of field (DOF) preview. If you can live without TTL flash, it is a better camera. It will cost $70 or so for a well-listed, tested body. The XD-5 offers all the same features except being able to see your selected aperture in the viewfinder and it can typically be had for $40.
The X-370 Also the X-300 and 370 s and n variants. This camera was the lower priced contemporary of the X-700 and X-570. It lacks TTL and DOF preview, but it does offer both metered manual and aperture priority exposure modes.
The XG series is the most affordable series offering aperture priority operation as well as manual exposure. The XG-M is the most full-featured, offering depth-of-field preview and an aperture readout in the viewfinder.
The SRT series, probably the most common on ebay - is an older, almost all metal construction series of bodies. There are two main drawbacks to using the SRT series. First, all offer metered manual but not aperture priority operation. Secondly, given their age and design, virtually all will need a CLA (clean lube and adjust) servicing, which will run you about $65 and up. This will correct the three typical problems of shutter speeds running slow, bad light seals/mirror foam, and a light meter calibrated to 1.35v instead of the commonly available 1.5v batteries. They're good, durable cameras (once they've been CLA'd) with a lot of die-hard fans, most of whom have used them for decades, but given how cheap the better featured models are, I'd find it hard to justify using any of the SRT's as your main body. In general they can be found for $20-120 in excellent condition depending on the model and servicing history. In my opinion, any older SRT camera ought to have a CLA done before you use it. Other models (the X370, X700, X570, XD series, XG series) can usually be used without a CLA, though all will usually need light seals.
Lenses: I've grouped the lenses into focal lengths and listed within each group some of the better commonly available (cheaper) lenses.
Fisheye-22mm: Minolta primes in this range are generally very well rated, but are rare and expensive. The Minolta 7.5mm fisheye is in the $500+ range; the 17mm f4 is about $400, the 16mm f2.8 fisheye is about $300, and the 20mm f2.8 is also about $300. You can sometimes find the Vivitar 19mm f3.8 or a Soligor/Spiratone 20mm lens in the $50-$80 range or a Sigma 16mm fisheye lens in the $150-200 range. The cheapest lens in this range is the Samyang 18-28mm zoom, which is usually $35-70. It's slightly softer than the common autofocus 19-35mm lenses for other camera mounts and it has more barrel distortion, but hey, it's cheap and wide.
24-28mm primes: Minolta has a nice 24mm f2.8 lens (about $100-150, though) and there are two pretty good 3rd party 24mm f2.0 lenses from Vivitar and Kiron (about $60, though somewhat rare) which I would recommend wholeheartedly. Also the Tamron 24mm f2.5 has pretty good specs. The Minolta 28mm f2.8 lenses are cheap ($20 for a Minolta Celtic, $30-40 for the better build quality models). 3rd party 28mm f2.8 lenses are VERY cheap (some even less than $10) but are a crapshoot in terms of quality. I personally use a 28mm f2.0 Kiron lens (about $50) which gets me very good results. Minolta did make their own 28mm f2.0 which sells in the $120-200 range.
45mm, 50mm, 58mm: Minolta made 45mm f2.0; 50mm f1.2, f1.4, f1.7, and f2.0; 55mm f1.7; 58mm f1.2 and 1.4 lenses. There are a couple optical variations of many of these lenses, denoted by different MC, MD, or Rokkor lableings. There's some information out there comparing the various lenses (see the rokkorfiles website). Generally speaking, the older lenses (generally denoted MC as opposed to the newer MD Rokkors and even newer plain MD's) have larger optics and a somewhat more expensive to produce optical designs but slightly inferior optical coatings (a drawback for performance, especially flare). The f1.7 lenses are generally $20-40 while the f1.4 lenses are $50-90. The f1.2 lenses are in the $300-500 range. The 50mm f1.4 and 1.7 lenses have the best optical resolution (better even than the f1.2's). There is no clear consensus over which lens is the best (best combination of sharpness, contrast, color rendition, eliminating chromatic abberations, eliminating flare), but all offer very good performance. I personally use a 50mm f1.4 MD lens for everything, although in the past I had a MC Rokkor 58mm f1.2 lens for situations where I want a brighter viewfinder, better bokeh shallow depth of field, and/or a more telephoto perspective.
Telephoto zooms (60-100mm to 200-300mm zooms): The Vivitar 70-210mm f3.5 lenses are good, cheap, and plentiful, and are in my opinion, the best "entry level" lenses in this group. At $20-50 they offer reasonable sharpness and contrast and allow macro focusing to 1:2.2 (or 1:4 depending on version). Other acceptable 3rd party performers include the Tamron 80-210mm f3.8-4.0 lens ($30, 1:2.8 macro and good optics), the Tokina made 60-300mm lenses (may be called Promaster; $20-50) and the Vivitar 70-300mm zoom ($20-50, 1:3 macro; slightly inferior optics, but longer reach). There aren't a lot of really good off-brand lenses in this range - a few of the best are the Tokina 80-200mm f2.8 ($150 or so; they appear every few months on ebay) the Tamron 70-210mm f3.5 SP ($70 or so) and the Vivitar Series 1 70-210mm f2.8-4 lens (but only the 3rd version; serial number starts with "28", not "9"). There are a lot of poor lenses in this range among the 3rd party manufacturers. Zooms are inherantly more optically difficult to do, and while Lentar, Albinar and the various other alphabet soup lens marketers may have been able to pull together an acceptable 28mm or 135mm f2.8 prime lens, the typical 3rd party cost-cutting measures resulted in a lot of flare-prone, low contrast tele-zoom lenses. The genuine Minolta tele-zooms (70-210mm f4, 80-200mm f4.5, and 100-200mm f5.6) are conservative optical designs. They have decent sized optical elements but small apertures and OK macro ratios, focusing no closer than 4' or so. If you can tolerate those limitations, their optical quality is fairly good for prices from $25 for a Minolta Celtic 100-200mm to $100 for a Minolta Rokkor-X 100-300mm. If you can live without zoom, there are primes in this range as well, most notably the Minolta 300mm f4.5 and f5.6 lenses.
Teleconverters: These are essentially worthless, especially when coupled with the cheap telezooms that they're usually sold with. They will technically enable you to get a shot, but it will be very low quality with little contrast and bad resolution. Worst of all, if they cause your max aperture to get smaller than about f8, you won't be able to use your split image prism at all to focus - you'll just have to guestimate focus based on the background. If you really need telephoto reach, get a decent quality 500mm mirror lens (not an Opteka, but Tamron and Tokina made good ones in the $100 range). If you insist on a teleconverter try to use it on a prime lens (Minolta's $130 or so 300mm f4.5 is an option) and try to get one of the higher quality 7-element versions (Kiron made a good one if you can find it).
Flashes: If you've got the X-570 or X-700 you really ought to get a dedicated flash to take advantage of the TTL capabilities of the camera. The Minolta PX360 is the best TTL flash you can get and costs about $70. It lets you manually set flash output (1/16, 1/8, etc. of full power) and it bounces and swivels. The 280PX is TTL but does not bounce or swivel, which is a serious drawback. The 132PX bounces but does not swivel. And the 80PX is a ring flash that attaches to your lens for macro use. These are the only Minolta TTL flashes. There are some dedicated off-brand flashes which work well. You need to find one that says it's dedicated for Minolta (but not for Maxxum). Vivitar made a good Series 1 flash that bounces and swivels, and there are also other Vivitar, Sunpak, and Albinar dedicated models which will do the job.
If you don't have a TTL body, you can use whatever standard flash you want, and you ought to be able to find a workable 3rd party bounce flash for about $10 plus shipping. The Minolta 320x is also a good flash, which bounces, swivels, and has manually selected output (very helpful; especially for objects close up) for about $25.
Good kits to buy for various budgets: This section is for the beginner buying into the system.
Under $50: Try to find a seller with a complete outfit for sale (this will minimize your total shipping cost, and you generally pay less for a group of items together). Look especially at the X-370 or XG series of cameras, but avoid the XG-A, since it does not offer manual override of its aperture priority mode. Consider the SRT cameras if you prefer their feature set and can find one which the owner guarantees. Make sure you get a good 45, 50 or 58mm prime lens. The most important things you want your kit to have are a flash that bounces, a 28mm wide angle lens or zoom that covers this focal length, and a telephoto lens. The only high quality lens you'll probably end up with will be the 50mm, but try to cover the wide and tele end with something. After your photography has progressed, you will be able to recognize the limits of the cheaper lenses this budget will get you and you can decide whether you can live with them or want to trade up.
$50-$100: Same as for under $50, but consider getting a TTL flash metering camera (the X-700 or X-570) with a TTL flash, but you'll have to be opportunistic to make this happen on this budget, and may not be able to afford the wide and tele lenses as well. Going with the XG or SRT series will give you better lens choices. If possible, get the Vivitar series 1 70-210 mm f3.5 lens (not the plastic f2.8-4.0 versions).
$100-200: Same as for under $100, but in this range, but also consider adding a super-wide lens (see above for some cheap options). Try to get some better quality lenses - Minolta 28mm and 135mm lenses are affordable upgrades. Get one of the 50mm f1.4 lenses instead of an f1.7 or 2.0 lenses. I would also strongly lean towards the X-700 or X-570 camera bodies in this price range.
$200+: Start with a basic kit of a quality 28mm, ~50mm, and a quality telephoto zoom with an X-700, or X-570 body and TTL flash. Alternately, you might want to substitute a 24mm and 35mm lens for the single 28mm lens. Add to this kit lenses to suit the particular subjects you like to photograph. Get a super wide lens; an 85mm or 135mm lens for portraiture; the Minolta 300mm f4.5 lens and a teleconverter for shooting birds and wild animals at a distance, a 90, 100 or 105mm macro lens for closeups; a wide to tele zoom if you want zooming flexibility (albeit at the expense of optical quality). Also consider a decent tripod (see the tripod guide I've also written).
Buying on ebay: I've bought a lot of Minolta manual focus gear on ebay and the following are some of the problems I've run into:
Light seals are often bad on bodies. This is more often the case than not, unless the seller specifically says the light seals have been replaced. Nevertheless, this is an easy fix. You just need to get a couple sheets of self adhesive light seal material, cut yourself some strips, clean out the old gunky light seals, and replace. It takes a half hour and anyone who has the mental capacity to figure out a camera can do it. Don't buy light seals marketed for your specific type of camera - get sheets of the stuff and cut your own. Try for pre-cut felt or foam strips to replace light seals and 2mm foam to replace your mirror bumper foam. I am a fan of Interslice's $10 light seal kits that he sells on ebay. The material all seems pretty good; you get a wide variety of stuff, and quantities are enough to do at least 8 cameras; probably more.
Capacitors go bad, especially on the XG series. I've only encountered this once, but you need to take the body apart and solder in a few new capacitors (I've purchased them on ebay from minoltadoc with good results) to fix it.
Sellers often don't know how to evaluate lenses. Some good questions for a buyer to ask (and for a seller to answer upfront) are: Are there any scratches or marks on any of the lens surfaces (front or back)? Does the lens have fungus or internal haze? When you look through the lens at a light, is there a lot of internal dust? (a little bit of dust is normal and makes little difference) Also when looking through the lens at a light, do the aperture blades move as they should when turning the aperture ring and flicking the aperture pin on the back of the lens? (sometimes the blades get oily and stick). Does the lens focus smoothly? A lot of sellers are lazy and won't check for you, but if they do and say the lens is good, 99 times out of 100, you'll get an acceptable lens. Also, note that lenses from humid places such as Florida and Hong Kong are prone to fungus if not stored in a conditioned space, so I would never buy a lens from such a place without a direct assurance of no fungus. Also,if you're looking for a particular lens and don't want the hastle of searching it out on ebay, keh dot com offers a very good selection of Minolta lenses for sale at a slight markup from typical ebay prices.
Camera bodies can be tougher to evaluate in an auction if the seller doesn't explicitly state what works and what doesn't on the camera. If you buy a camera body and need it to work, your best bet is to get one from a seller who sounds like he knows what he's talking about and at the very least says the thing has a battery in it and works currently. Watch out for SRT's, though, because even if a seller verifies the shutter and meter look about right, you still can end up with a slow second shutter curtain and pictures that fade from under exposed to over exposed (a CLA fixes this).
Those caveats to buying aside, the Minolta manual focus system is a very good system to get into. There's a lot of quality gear out there with good features which is very cheap, even by manual focus standards. Digital presents some conveniences for image manipulation and instant feedback of whether your picture came out or not, but film still provides the ability to take slightly higher-resolution shots. And the learning experience that these manual focus film cameras provide is invaluable and enables people to take better film and digital pictures.
Adapting to digital: The easiest digital cameras to mount Minolta manual focus lenses to are the Sony NEX system, the 4/3 system and the micro 4/3 system. These systems all have film/sensor plane to lens mount distances less than that of the Minolta system. You can adapt these lenses to the Canon, Nikon, Sony/Minolta, and Pentax digital SLR's, but adapters to these systems will all require an adapter with an optical element (or the focal distance will be shifted in and you lose infinity focusing). This will slightly degrade your optical quality.
For Further Information: I've found the following sites helpful (ebay doesn't like links, so you'll have to type them into your browser yourself).
www dot rokkorfiles dot com - Great info and comparisons of a lot of the most common bodies and lenses.
members dot aol dot com/manualminolta - Really comprehensive info about Minolta bodies and lenses. You've got to navigate to find it, though. Especially see their chart of all the Minolta bodies and their features.
www dot paulfvs.dds.nl/ - Some general Minolta information and a good source of old magazine lens test results.
www dot photodo dot com - Some lens testing information.
www dot photo dot net - A lot of good general photography information. If you just starting out in photography I'd recommend going through their beginning photography tutorial because I think it's explained well (i.e. - talk about lighting first, then move on to composition and technical information.) Additionally, if you're stumped for a piece of information on the net, a search of their site can sometimes turn it up.
There, enough writing. Happy shooting!