Daniel Hindes: September 2009 Archives

No. The confusion comes from the corporate history of Minolta, Konica, and Sony. Back in the 1980's Konica and Minolta were separate companies with separate, incompatible camera systems. Sometime after 2000 Minolta bought Konica, but by that time Konica had long discontinued its cameras, and made mostly film and specialty devices (like copiers and printers). Minolta renamed itself "Konica Minolta" but the cameras sold as "Konica Minolta" cameras were made were backwards compatible only with Minolta Maxxum mount lenses. Then in 2006 "Konica Minolta" sold its entire camera business to Sony, so what had been the (Konica) Minolta Maxxum system is now the Sony Alpha system.

Sony bought Minolta's camera business to compete with Nikon and Canon at the high end of the camera market. Sony only entered the camera market with the advent of the point & shoot digital camera, and was very successful. But they had no legacy SLR system, and in the end found it easier to acquire the Maxxum technology than to build an entire SLR system from scratch. The other advantage was the existence of millions of used Minolta Maxxum mount lenses on the used market. People would both want and need a new Sony digital camera body, but could use older Minolta lenses on it. This provided a built-in market for new Sony cameras (people with thousands of dollars of quality Minolta Maxxum lenses would sooner buy a Sony camera than sell everything and switch to Canon or Nikon) and value conscious consumers could buy a Sony body and get inexpensive used Maxxum mount lenses. However, even though Sony bought "Konica Minolta's" Maxxum mount technology, this had nothing to do with the old Konica mount system. The old Konica mount from the 1980's remains orphaned, meaning that there is no digital camera on which 1980's manual focus Konica lenses will work.

I recently acquired a lens that looked brand new. How much dust is inside a brand new lens? With the naked eye could see only one particle, a tiny fleck on the element that was immediately in front of the aperture. Then I took a really bright light, held the aperture open and shined it through the lens from the back. Under such harsh lighting it was possible to see quite a few miniscule particles of dust that did not show up when you looked in from only one end of the lens, either front or back, even with a light. Curious, I looked at quite a few other lenses I have in the same way and virtually all of them had some amount of microscopic dust on the interior elements that was only visible if you shine a bright light through from the back. Even more curious, I opened a brand new Sony 50mm f/1.8 that can't have been manufactured more than four months ago, and I was able to see some microscopic dust on the interior elements of this brand new lens as well (not as much as in the used lenses, but it was there). From this I conclude that if you look closely enough, with bright enough light, and from the right angle, you will find some sort of dust on every lens. I've tested many of the lenses on my Sony A700 and can say that what dust there is on most lenses has absolutely no discernible influence on image quality. Thick coatings of dust that make the glass foggy will of course degrade image quality, but a few particles that you can only see with a flashlight will have no influence.

Yes and no. It is important to distinguish between the high-end lenses and the sub-$500 consumer zooms, both from Sony and from Minolta, and to understand sample variation. The high end lenses are essentially the same lenses, built in the same factory, to the same standards, and are essentially comparable. The differences are in the additional coatings on the Sony lenses to optimize for digital sensors. These improvements show up under certain specific shooting conditions. The consumer zooms are more variable.

One lens model that I did test extensively was the Sony vs. Minolta versions of the 50mm f/1.4, which is the same optical design. After extensive testing on an A700 and could find no difference in overall image quality, meaning both lenses outresolved the 12MP sensor. This is not surprising, since they are the same design. One area that I did find differences was in glare. If you have a large, dark image in the center of the frame and bright light all around it, with both lenses you will get a purple dot in the center of the image from light bouncing off the sensor, hitting the rear element, and bouncing back onto the sensor. However, with the Sony lens the dot is really faint and barely noticeable, and with the Minolta 50mm f/4 the dot is quite bright. The difference is due to better anti-reflective coating on the Sony lens.

If I have learned one thing by testing all these lenses is that sample variation is a very real issue. For example, I have two Maxxum 75-300mm D lenses right now that are not particularly sharp, even at f/8, and especially at the corners. And just today I tested a third that is absolutely tack sharp all the way across at f/8. So is the Maxxum 75-300mm D a good lens? If you get a good one it is! I've had the same experience with the 28-100mm Maxxum lenses. So I'm willing to bet that the cheap Sony lenses are just as variable (and especially used ones that someone may have banged around a bit). Consumer lenses are not assembled to the same tolerances as the multi-thousand dollar lenses, and the materials are also cheaper. As a result they can get out of alignment (sometimes even from the factory) and produce images that are softer than they would be if everything were just perfect. That is, the individual lens may not represent the design very well. This can also happen if the lens gets dropped or banged around; the internal elements can get slightly out of alignment, causing a softer image. A further issue is around quality has to do with who makes the lens.

Now most of my information comes from posts on the Minolta Yahoo group and dpreview.com forums that I read years ago, but I seem to remember hearing that after about 2002 Minolta outsourced the manufacture of their consumer zooms to Cosina. Sony probably does the same. Minolta still manufactured their high-end G lenses in their own factory. However, I doubt that either Sony or Minolta made their own glass. I recall hearing that Hoya makes over 90% of the optical glass used in the world, so it is a likely bet that all the lens makers get theirs from Hoya. What the lens makers do is grind the glass they buy from Hoya into the precise shapes needed for their lenses, and then apply coatings.

Where the various companies also differ most is in the coatings. Minolta used to be famous for the total consistency of their coatings. But this was before they started making all-plastic low-end consumer zooms. The high-end glass still had the consistently balanced coatings, but the consumer lenses were variable. Some of the new Sony lenses, specifically the Zeiss models, have coatings with a color balance somewhat different from the one that defined the Minolta lenses. I'm not sure of the details of where Sony lenses are produced today, but Sony did acquire Minolta's lens factory. They probably only use it to produce the G lenses. But the really great thing is that all the old Minolta glass, back to 1985, works as well or better on the Alpha bodies (thanks to the lens motor being in the camera, not in the lens). That makes Minolta lenses on a Sony body an incredible value option for consumers!

In terms of overall build quality, Minolta's xi power zoom lenses from the early 1990s may represent a high water mark. Minolta's lenses, like the cameras and lenses from all makers, have gotten cheaper over the years, in more ways than one. The upholstery in 1930's Mercedes cars was made to last 100 years. Today a car is doing exceptionally well if it makes it to fifteen, and the upholstery certainly will not feel new! In the 1970's and 1980's cameras--and especially lenses--were made to last a half century. They were also relatively more expensive in inflation-adjusted dollars. The famous Beercan (Minolta's 70-210mm f/4 lens from 1985) cost about $700 new in today's money. The 28-105mm xi powerzoom lens was also sold for $400 new, or about $900 in today's money. But everybody wants things for less money, so camera makers obliged (as did Mercedes in the 1990's) and shaved costs in production. Quality declined.

By the late 1990's the kit lenses for the cheaper (consumer) cameras were so cheap that when Minolta made something to the old standards they needed a way to explain why it cost so much. So Minolta introduced the "G" line of lenses to indicate the quality was still very high. And G lenses sold in the $800-2000 range, new. Today Sony still makes lenses as good as the best Minolta glass. You just have to pay for it. Consider the Sony Alpha "Carl Zeiss" and "G" series lenses. Pricy, yes. But they are as good, and often better, than anything Minolta ever made. I've heard nothing but praise for the image quality of the 16-80mm DT Carl Zeiss zoom lens (Sony model number SAL-1680Z, not to be confused with the SAL-1680, no Z on the end!). The build quality is criticized as plasticy, but no one ever disparages the image quality. That lens sells new for $750 today, or about what a 28-105mm xi lens cost new, when adjusted for inflation.

In photography, image quality usually comes at a high price. There are exceptions (see my article on lens bargains for Sony alpha digital camera). Some of the best lenses in the last 20 years are available at greatly reduced prices on eBay. Owners of Sony alpha digital cameras have a bit of advantage. Because the lens motor is inside the camera body, even the very oldest Minolta Maxxum mount lenses will perform quite well on a modern digital camera body. Owners of Nikon and Canon digital cameras have to be very careful not to purchase and lens that contains an outdated motor and therefore focuses unacceptably slow.

Back in 2001 I wrote an article titled "Can you use Minolta manual focus lenses on an autofocus body?" That was before  Minolta released their first digital SLR, and before they sold their camera business to Sony. The information, however, is still valid, and applies to the Sony Alpha digital SLR cameras for the same reasons. The short answer is, "No, you can't use older Minolta manual focus lenses on a Sony Alpha DSLR camera". They are different mounts, and would require an adapter. That's the bad news. The good news is an adaptor exists. However, it has a piece of glass in it, kind of like a teleconverter, and this is a problem.

Why does the adapter have glass? The MC/MD and AF mount rings are different sizes (the MC/MD ring is about 30% smaller). So one side of the adapter accepts the MC/MD lens, the other mounts to the AF body. Now any adapter that can do this, purely from the mechanics, is of necessity several millimeters too thick. Without correcting optics, it would become in effect a short extension tube. And why is this a problem? If you've ever used extension tubes (which are great for their intended purpose!) you would notice that when the lens gets further away from the camera, the focal plane gets closer to the front of the lens, but the lens will no longer focus to infinity (the depth of field gets narrower too, and often curves). Now this is just what you want for macro photography, but not for much else. So to allow the Minolta manual focus MC/MD lenses to focus to infinity, a pieces of glass is necessary to correct the for the problem of the lens being slightly too far away from the film plane (or digital sensor plane). In such adapters, this piece of glass is usually about 2cm in diameter (not ideal for large aperture lenses in the first place) and is also not of very high quality (reasonable quality, to be sure, but not high).

The result is that when you mount your expensive lenses on this $40 adaptor, they all become considerably worse (I've done tests with an MC 58mm f/1.4, an MD 28mm f/2.8 and a Rokkor-X 135 f/2.8). The resulting pictures look pretty bad when compared to these same lenses on the intended camera body (a Minolta manual focus body like the X-700). Put in absolute terms, the results were worse than the cheapest 28-200 AF zoom in every area except distortion. That is, sharpness and contrast suffered noticeably. In digital cameras, you'll notice this even on a six megapixel body. On a film camera, if you never enlarge your pictures beyond 3x5" (9x13 cm) then you may not notice. Likewise, if you have never developed an eye for variations in contrast between lenses, and can't see the practical difference between a $100 zoom and an $800 fixed focus lens, then again, you won't have any problem with the results. In my test, a Sigma UC III 28-105 AF zoom (about $150 new, today you can get them on eBay for $50) gave instantly visually better results than the best lenses through the adaptor, and on 3x5" prints! No magnifying glasses, no getting really close. Lay them all out on the table, and you can pick out the ones from the adaptor vs. the ones from the Sigma consumer zoom from a distance.

The pictures through the adapter are still better than most plastic lens point&shoot film cameras, but that is not a very good reference point. Of course, the MC/MD lenses are wonderful on an SRT cameras (and better than the Sigma zoom). So was it worth it to get a $40 adapter from China so that you can use high-quality Minolta manual lenses on a Sony alpha digital camera? To me the answer is clearly no. While it is technically possible, the results do not justify it in the least. Even a used $40 basic consumer zoom lens will produce better pictures than a top-quality prime through these adapters.