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Modern Classic SLR Series
Minolta Maxxum 7000 AF SLR       camera - Part VII
First Generation AF Lenses by Minolta for Maxxum       7000- Part I

  The AF Technology to   create new designs, new capabilities

One great product resulted   from the research from the birth of Maxxum project was an array of an entirely   new series of Minolta interchangeable autofocus lenses. Employing a different   lens mount from the previous manual focus system, Minolta has decided to opt   for a revised lens mount specifically for the autofocus camera which was not   compatible with previous lenses. Initially, this has dampened the good spirit   of even the many Minolta faithful but the leap in technologically advantages   the new camera brought were so great and gradually it was well received even   for the hardcores.

Naturally, the first           generation of early Minolta AF lenses were not as "fanciful" as           compared with today's modern AF series of lenses. But during those           days, Minolta did has a lot of things to yelled about as that tactical           advantage of being the first to introduced a body integrated AF system           has offered the designers a free hand to express their talents. These           lenses, each has been exactingly crafted by Minolta's           ''opto-electronics" technology to create not only completely new           system of extremely compact, lightweight, high-performance optics for           the Minolta 7000 but also total camera-to-lens system integration. A           ROM IC (Read Only Memory Integrated Circuit) has been built           into each of those Minolta AF lenses to automatically transfer more           than 30 essential lens data to the camera's computer           for autofocusing and automatic exposure control, etc.

Initially, there were   twelve Minolta autofocus lenses to choose from between 24mm and 300mm in focal   length; although the selection was still considered limited but it was still   by far regarded as having the widest selection of interchangeable lenses for   any AF SLR on the market, the focal length and lens types was carefully   introduced with the speed and precision of Minolta's high-tech Autofocus   System in an extremely wide range of applications.

The           lens family has grown in strength and it has mushroomed to more than           50 lens types being introduced over the years. Naturally and           amazingly, most of these lenses, regardless as current models or           discontinued ones, still able to serve the original Maxxum 7000 AF           camera which was introduced almost 1-1/2 decade ago.

I           cannot keep tracked with all these years of development of lens types           in this site, instead, just for cross reference, listed here featuring           with the original batch of the Minolta AF lenses to enable some of you           who has the special interest to compared the rapid development of AF           technologies employ in Minolta AF system. Well, despite their aging           history, it was quite amazing to realize many of those original lenses           were indeed high performance optical tools that have incorporated many           up-to-date technological advantages which you may even find them           ranked highly with today's modern AF lenses. Some of which deployed           are listed below:


         

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Minolta   Interchangeable Autofocus Lenses
  Initial Minolta 7000's   AF lens system comprised of 12 Minolta AF lenses with focal lengths ranging   from 24mm to 300mm. Included are an 1:1 macro lens and 5 zoom lenses with   macro capability covering a focal range from 28mm to 210mm. The early batch of   lenses were still far from complete in every aspect, but still, most of these   lenses with varying degree of price and performance should be quite adequate   for most photographic applications.

By the           time the Dynax 7000i was introduced a few years later, the AF lens           family has already 16 prime lenses ranging from 16mm Fisheyes to a           massive AF 600mm f/4.0 APO super telephoto lens, most           noticeable was the addition of 20mm focal length which has extend from           the original 24mm field of view; on the other hand, the zoom lenses           have grown from the original 5 to 12 choices which includes a high           performance AF 80-200mm f/2.8 APO lens. Special lenses such as           macro/close-up photography, Minolta has added a AF 100mm f/2.8           Macro in addition to the AF 50mm f/2.8 Macro with 2 APO           tele-Extenders at 1.4X and 2X ratio. But since we are still focus           on the original lenses, we just go through the various lenses and           outline their respective optical characteristic and usual application           briefly.

Wideangle lenses at 24mm and 28mm focal   length
  Most suitable for   landscapes, group shots or creating interesting perspectives. A bright   viewfinder image makes precise composition easier than ever. The AF 24mm has   only about a 10° smaller angle of view than the 20mm lens which introduced at   later stages. The lens provides about twice the image of a 35mm lens and about   three times that of the 50mm lens. With a highly versatile 84° picture angle,   the 24mm lens is a perfect compromise between ultra and regular wideangle -   ideal for landscape, travel, candid and architectural photography. This is the   widest of the wide-angles of the initial group of Minolta AF lenses. Compared   with wider lenses, it is a lot more easier to master. Also, the strong   rendition of perspective can be controlled quite easily on this lens.   But more importantly,   other   than including a wider scope of background information with its wide angle of   view, this lens still permit the photographer to maintain a close visual   relationship with the subject, which is especially useful in photojournalism,   reportage or news photography.
  The AF   28mm focal length is considered today to be a standard wideangle by an   increasing number of photographers especially for those who finds they always   has to deal with PR photography. The main advantage of the 28mm lens is its   ability to capture a fairly large subject area without creating undue concern   over its perspective rendition. I always thought a 28mm is a better investment   than a 35mm or a wider 24mm to handle all round photographic situations. A   comparison of 24mm, 28mm and 35mm angles of view should give you an idea of   how a 28mm performs.


  

AF 24mm         f/2.8                    Construction: 8           elements in 8 groups Angle of view: 84* Minimum focus:           0.25mm Minimum f-stop: f/22 Dimensions: o65.5 x 44mm Weight:           215 g

AF 28mm         f/2.8                    Construction: 5           elements in 5 groups Angle of view: 75o Minimum focus:           0.3m Minimum f-stop: f/22 Dimensions: 665.5 x 42.5mm Weight:           200 g

Well, compared   with the moderate view of an usual 35mm wideangle lens which was considered as   the 'normal wideangle standard"during the seventies, the typical wideangle   effects become obvious at 28mm but not as apparent as the 24mm counterpart and   that could well explained why it is such a clear favorite among many amateurs   and serious users alike as it can be used for a wide variety of applications   including commercial, industrial, architectural, travel, landscape and news   photography.
  
  Another   significant advantage of the 28mm focal length lenses is, most modern   electronic flash units are designed to cover the field of view of a wideangle   35mm of 63 degree picture angle. However, since most electronic flash provides   an wide-adaptor, you may use it to extend and has the field of view of the   28mm (or even at 24mm focal length) lens well covered.

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Compound Aspherical           Lens In the Minolta AF 35-70mm f/4 zoom lens, an exclusive           compound aspherical element is used to make the AF 35-70mm lightweight           and compact. Minolta's advanced lens manufacturing techniques assure           utmost performance from this unique new lens.

  

Double Floating           System With its adoption of a unique double floating           system, the Minolta AF 50mm f/2.8 macro lens corrects inherent           distortion, field curvature and other spherical aberrations in           addition to providing life-size macro photography without use of an           adapter. During focusing, three groups of elements move independently           for minimal barrel extension and faster autofocusing.

  

Internal Focusing           System Both the Minolta AF 135mm f/2.8 and AF 300mm f/2.8           APO tele lenses use an internal-focusing optical design to enhance           high-speed autofocusing. Since focus is adjusted by moving the           smaller, lighter central elements rather than the heavier front           elements, autofocusing is faster and more precise.

   

Rear Focusing           System The Minolta AF 28-135mm f/4-4.5 zoom lens is the           first zoom lens in the world to use a unique rear-focusing optical           design. Three major design benefits are- faster autofocusing since the           moving mass of lens elements is greatly reduced; reduction. of overall           size and weight; closer minimum focusing distances.

               

Anomalous Dispersion           (AD) Glass The Minolta AF 300mm f/2.8 Apo tele lens uses           Minolta's exclusive anomalous dispersion (AD) glass whose low           refractive index and low anomalous dispersion are particularly           effective in correcting lateral and longitudinal chromatic aberrations           which are characteristic of conventional telephoto lenses. Minolta's           exclusive Achromatic coating further improves color rendition and           enhances image contrast.