In the newest test we have compared the 2.8/300mm designs available in the Sony/Minolta DSLR system. While the Minolta AF 2.8/300mm APO G certainly is a very good lens, the Sony AL 2.8/300mm G SSM is better - much better indeed. Both lenses have an excellent center resolution, even wide open. At f2.8 the Minolta has even slightly more contrast than the Sony. For excellent detail resolution in the corners, however, the Minolta must be stopped down to f8, and CA's are visible. The Sony, due to its three AD glass elements, is completely free from CAs and has a extraordinary detail resolution over the entire field - even at f2.8.

Sony's new AL 4-5.6/70-400mm G SSM zoom has a similar overall performance as the Minolta AF 2.8/300mm, but virtually no CAs. The surprise of the test is the small Minolta AF 2.8/200mm APO & 1.4x Tele Converter combination: At f5.6 clearly more details than the Minolta AF 2.8/300mm APO G! The old "big beercan" Minolta 4.5-5.6/75-300mm is quite soft wide open, and detail resolution is not satisfying. Only at f11 this legacy lens can cope with the 24mp sensor of the alpha 900.

Since Nikon produced the first 2.8/300mm lens in 1972, and Canon followed in 1974, the 2.8/300mm designs are classics. While Minolta had made a MD 2.8/300mm prototype, the lens was never released. Minolta, however, produced the very first autofocus 2.8/300mm lens (1985). Three years later the AF was re-designed; the optical system however remained unchanged (AF 2.8/300mm APO G HS, 1988). In 2003 the 2.8/300mm APO G SSM (D) was released - the first Minolta lens with SSM ultrasonic AF motor. The optical design was completely new (e. g. three AD lenses instead of two), and the lens was immediately recognized by the German "fotomagazin" (issue 2/2004) as the "best 2.8/300mm available": "A dream ...". In 2006 this lens re-appeared as the Sony AL 2.8/300mm G SSM. Currently only one piece per day can be manufactured (personal communication, Sony Switzerland).

For three weeks I could compare one of these rare beasts with my own Minolta AF 2.8/300mm APO G HS, along with the new Sony AL 4-5.6/70-400mm G SSM, the classical Minolta 2.8/200mm & 1.4x APO Converter, and the "big beercan" 4.5-5.6/75-300mm were compared as well. To be sure about my findings I ran several test series; the results were consitent with the series published here.

The Sony 2.8/300mm G SSM (same optics as the Minolta 2.8/300mm APO G SSM) is clearly the best lens of this test, and probably the best I have tested ever. The detail resolution over the entire field of the alpha 900 (24MP full frame sensor) is perfect, even in the extreme corners. Stopping down to f4.5 slightly increases the contrast, and from f8 onwards we already can see some effects of diffraction. Vignetting is quite pronounced at f2.8, but virtually gone at f4.5.

The Minolta 2.8/300mm APO G HS is perfect in the center, aven at f2.8. Corners though have less details and clearly more CAs. Stopping down to f8 increases the corners to excellent levels - apart from the CAs. The overall performance of the lens is very similar to the Minolta 2.8/80-200mm APO G @ f=200mm.

The Minolta 2.8/200mm APO G plus 1.4x APO Tele Converter is an excellent lightweight 4/280mm lens. One should avoid shooting f4 (very low contrast); already f4.5 is much better, and at f5.6 the combination is actually better than the Minolta 2.8/300mm APO G!

The Sony 4-5.6/70-400mm G SSM has already a very good reputation, even though it's just a few months on the market. The lens clearly has "G" level, both mechanically as well as optically. It is big, heavy, and ... silver, but it's worth it's price. At f=70mm it outperforms any lens tested before (e. g. the Minolta 28-135mm, the Zeiss 2.8/24-70mm and the Sony/Minolta 2.8/70-200mm G SSM). At 300mm the lens has no CAs at all, and a detail resolution similar to the Minolta 2.8/300mm APO G HS at f5.6. Contrast and detail resolution are well balanced ("minolta-like"), resulting in a nice color rendition. Vignetting is rather low.

Finally we did test the venerable Minolta AF 4.5-5.6/70-300mm as well ("big beercan", fully metal) - be aware: there are other Minolta 4.5-5.6/75-300mm lenses available; all of them are worse than the "big beercan" tested here). Around 1986 it played the same role in the Minolta AF system as the 70-400mm now. The lens is quite soft wide open (f5.6), details are missing, and for good results one must stop down to f11.

Before sharing the actual test results I'd like to show four pictures.

Working with a 2.8/300mm lens means using its shallow depth-of-field. While the Minolta AF 2.8/300mm reaches its optimal corner resolution only at f8 (center is perfect at f2.8!), the Sony/Minolta 2.8/300mm G SSM is completely free from such limitations: f2.8 is fully usable also for landscapes and architecture. I was surprised to see the difference even between f2.8 and f4 shots; f2.8 looking much smoother and "calmer". If you go for the Sony f5.6 telezooms, you will never be able to get the incredible smooth impression of the f2.8 images; the foreground (or background) usually has too many distracting details. The situation is even worse when using a "old" Minolta AF 75-300mm zoom: while it delivers remarkably sharp results at f11, you can't separate your object from the fore- or background any more.

As usual the test was run under the following conditions:

Camera: Sony alpha 900 DSLR with Vertical Grip

Lenses and AF: AF individually adjusted for each lens with "Micro AF"; central (f2.8) sensor used

Tripod: Manfrotto 055CB with three-way-head Manfrotto 410

Camera settings: 24MP RAW&jpeg, ISO 100, mirror lock up, "steady shot" off

RAW conversion: converted with Photoshop (sharpening 50, radius 0.5, detail 50)

	Sony AL 2.8/300mm G SSM Even wide open the 300mm SSM G is close to perfect - the corners of the 24MP full frame sensor have as many details as the center, and there are no CAs at all - neither longitudinal nor lateral. Vignetting is quite strong, but can be corrected easily by post-processing
	Minolta AF 2.8/300mm APO G HS At f2.8 the "old" Minolta is close to perfect as well - but only in the central part of the image. Corners have less details and some CAs.
	Minolta AF 2.8/200mm APO G HS plus Sony 1.4x APO Converter The combination of 2.8/200mm APO G and 1.4x APO Converter is more "Minoltian" than the 2.8/300mm: less contrast, but more details, at least in the corners.

	Sony AL 2.8/300mm G SSM Contrast has improved, detail resolution is at it's best, and vignetting is reduced to acceptable values. Stopping down to f8 slightly decreases the overall performance.
	The lens is stil not perfect, at least in the corners: CAs and detail resolution are quite far from the Sony 2.8/300mm G SSM. Only at f8 the borders become as detailed as with the Sony 2.8/300mm G SSM at f2.8 ...
	What a surprise: The 2.8/200mm APO plus 1.4X converter is better than the 2.8/300mm! Clearly better detail resolution in the corners, less CAs - and slightly less contrast.
	Wide open, the new Sony 70-400mm G SSM has a similar detail resolution as the Minolta 2.8/300mm APO G at f4.5. There are, however, no (!) CAs, and the contrast is slightly lower. Remarkable indeed.
	The big beercan - quite a good performer around 200mm - doesn't reach the levels of the other lenses tested here, even though it was quite pricy in 1986.

	At f 11 the Sony 70-400mm G SSM has slightly improved corners, but center performance is already decreasing - a result of diffraction limiting the resolution.
	At f11, also the "big beercan" delivers decent results, apart from the rather pronounced CAs.