In the mid 1970's Minolta only had four zoom lenses available to photographers, however with the development of computer aided design in the late 1970's the market for zoom lenses exploded, driven by the upsurgence of third-party lens manufacturers. To meet this growing demand Minolta released an extensive range of zoom lenses, and by 1982 there were 13 Minolta zooms available, covering the focal lengths from 24mm to 500mm.

In 1983 the Minolta catalog records its price as Y94,000, over twice the price of the 24-35mm f/3.5 (Y46,000), and more expensive than the 135mm f/2 and 200mm f/2.8. It is possible that this price reflected the complexity of costruction (13 elements in 10 groups), however personally I believe that Minolta felt the price was justified based upon the performance and range of the zoom, which was exceptional for its era. So the question is, how good is it when compared to prime lenses?

In order to get a better idea of the strengths and weaknesses of the 24-50mm I decided to conduct some informal testing against some of the great Minolta primes that I use regularly. Accordingly, the shots below show comparisons against the 24mm f/2.8, 28mm f/2, 35mm f/1.8, and the 50mm f/1.4, all renowned as top performers.

All of the crops below have had moderate use of the unsharp mask (150%, radius 0.3, threshhold 3).

24-50mm f/4 - centre

24-50mm f/4 - corner.

24-50mm f/4 at f/4 - centre

24-50mm f/4 at f/4 - centre

24-50mm f/4 at f/4 - centre

Based upon the results above, I believe that the 24-50mm f/4 Zoom Rokkor-X is an exceptional zoom, recording excellent results when stopped down, and very creditable results even when wide open. Performance appears best at the shorter end, and when stopped down at this level its results approach those achieved by top prime lenses. At the longer end of the zoom the results fall away a little when compared to the primes, with centre sharpness not quite at the same level, and corner sharpness similarly poor at f/4, and improving at f/8 (but not to the level of the primes). The zoom also appears to suffer more from glare, as would be expected.

While I have not specifically covered off on this fact in the testing, I would comment that the distortion of the lens appears negligible at both wide and long ends, and I did not find any real evidence of light fall-off at f/4.

With my absolute passion for sharpness and the preparedness to lug around a bag of prime lenses, I will probably still use my primes in preference to the zoom for photographs I plan to enlarge or project. However, photographers who prefer the flexibility of a zoom will find that this lens is excellent, and is probably as good as it gets for Minolta manual focus users wanting wide angle coverage from a zoom. The lens covers a large range of focal lengths, and is extremely well constructed. Furthermore, at a price normally under $200 on ebay it is quite affordable, and a great option for someone seeking a range of wide angles..

The only real drawback of the lens is the f/4 minimum aperture, which limits the capacity for it to be used handheld indoors, and can make precise focus difficult in low light situations. This is a small price to pay for the convenience of a zoom as sharp as this one.