Review: Minolta AF 70-200mm f/2.8 Apo G (D) SSM 1. Introduction
With telephoto lenses, depth of field is narrow, the
long focal lengths make hand-holding tricky, and you're often shooting subjects
that don't stand still. This means that fast and precise focusing is critical,
bad bokeh has a really unpleasant effect on most pictures, and you'll be
shooting your lens wide-open with Anti-Shake turned on most of the time to minimize camera shake. So
ideally you want Anti-Shake, fast and accurate focusing, good bokeh and good
optical performance at the largest aperture. So lets see how the new Minolta AF
70-200mm f/2.8 Apo G (D) SSM lens fits this description. The AF 70-200mm f2.8 Apo G (D) SSM lens, together with the AF 300mm f/2.8 Apo G (D) SSM lens, are the first Minolta lenses to use a supersonic wave motor for focusing. This is equivalent to the Canon USM and the Nikon Silent Wave motor. This AF motor gives a much more quite and smooth AF operation. More on that later. The lens is also part of the Minolta AF G – Series that only uses Minolta's finest optical glass. In February 2004 I went on a trip to Bandhavgarh National Park in India to photograph tigers. In addition to my Minolta equipment I brought a Canon EOS 10D with a Canon EF 70-200mm f/2.8 L USM IS lens to try out digital. (This was before Minolta released the Dynax/Maxxum 7D). The Canon combination was perfect for taking pictures of tigers from the back of an elephant. I loved the lens but hated the camera as I could not get used to the Canon interface. When Minolta released the Dynax 7D I rushed to the shop to get it and later sold the Canon equipment. So when I was heading back to India in February 2005 I decided I just had to get a Minolta 70-200 lens for the trip. Instead of buying the older AF 80-200mm f/2.8 Apo G lens I went for the new SSM version as I really loved the quiet and smooth focusing on the Canon 70-200mm USM lens. So far I have only used the lens on the Minolta Dynax 7D digital SLR as my Dynax 9 has to be updated to allow the lens to focus. A summary of my thoughts on the lens follows. Remember, this is a subjective review and your opinions might be different. This review is based on my experience with one lens only and sample variations might occur. Anyway I hope you find it useful. 2. SSM Focusing The SSM lenses will not autofocus with camera models introduced before the Minolta Dynax/Maxxum 7. The only exception is the Dynax/Maxxum 9 which can be upgraded to take SSM lenses. When you purchase a new SSM lens Minolta will upgrade one Dynax 9 for free. The lens can be used in manual focus on all Minolta cameras. 3. Teleconverters The SSM lenses will only autofocus when coupled with the new Minolta AF 1.4x Tele Converter Apo (D) and Minolta AF 2.0x Tele Converter Apo (D). These converters are also compatible with all other Minolta lenses. The only difference between these converters and the Tele Converter II Apo's are that the new ones have eight lens contacts versus the older ones five. 4. Lens data
5. Appearance and Handling This lens was released in March 2003 and is the latest Minolta lens in the G - Series, together with the 300mm f/2.8 Apo G (D) SSM. When you first see this lens it gives you an impression of solid quality and it sure is a work of art. The lens barrel is all metal and has a finely crinkled-paint white finish. It is the same type of paint used on the 28-70mm f/2.8 G lens and looks like it will withstand wear better that the white finish of the older G lenses. The manual focusing collar, placed at the front of the lens is wide and do not rotate when the lens is autofocusing. The customary golden ring, designating a G construction, is placed just in front of the manual-focusing collar. Zooming is by another wider collar located around the mid part of the lens barrel. The lens has three focus hold buttons placed right behind the manual-focusing collar. By pushing one of these buttons you can stop the autofocusing. When releasing the button the lens will start focusing again. By altering the custom functions of your camera you can set these buttons to perform different functions like DOF preview. A read-out window for the distance scale, without depth-of-field indications, is placed just behind the three focus hold buttons.
Behind the zoom collar there are three switches. With the upper one you can switch between autofocus or manual focus. The second one sets the lens in standard Direct Manual Focus (DMF) or full-time DMF. Standard DMF allows you to fine tune the focus manully after the AF system has locked onto the subject. Full-time DMF gives you access to manual focus control at any time by simply turning the focusing ring. The last button sets the focusing range, from 1.2m to infinity or from 3m to infinity. This can be used to make the focusing faster. The switches are easy to reach and change, still they will not accidentily change position as you handle the lens. This was a big problem with the Canon 70-200mm f/2.8 L USM IS lens. Several times when I brought the camera up to take a picture either the AF or the IS was disengaged accidentily. This happened when I held the camera and lens combination around the lens barrel as I sat on top of an elephant moving through the jungle in search for a tiger or when I had the camera wrapped in a towel to keep dust out when moving around with a jeep at full speed. With the Minolta lens this is not a problem. All the way at the back of the lens is solidly built tripod mounting collar that rotates 360 degrees and can be locked at any position. It can easily be removed when you are using the lens handheld. It is a good and compact design. The lens hood is a large (at least for Minolta) petal-shaped hood with a bayonet mount. A very nice detail is the small sliding lid that when opened gives you access to a polarizing filter if one is attached to the lens. This makes it possible to use the lens with the lens hood when using a polarizer without putting your whole hand inside the lens hood. Smart and simple solution. The hood is covered with black velvet on the inside to reduce reflections.
The lens uses the totally new (at least for Minolta) SSM focusing. It means that the lens uses an internal motor to adjust the lens elements to focus. The design achieves a much quiter and smoother focusing than the in camera motor used on the other Minolta lenses. The biggest difference is that the lens autofocuses without any noise, which is hardly the case with other Minolta lenses. Focus tracking is also much better and the lens does not run all the way out to infinity when it looses focus like the other Minolta lenses have a tendency to do ever so often. I don't think the speed of the motor is much faster. By that I mean the time it takes the lens to focus from one distance to another. I would say it is about the same as the Minolta 200mm f/2.8 Apo G on the Dynax 9 (which is not bad as I find this combination very fast). But the overall feeling of the focusing is much better. Compared to the Canon EOS 10D and the EF 70-200mm f/2.8 L USM IS lens I would say the focusing with the Minolta Dynax 7D is about the same. And that applies to focusing speed, noise and focus tracking. The front element of the lens does not rotate and the length of the lens does not change when the lens is focusing or zooming. This means there is no problem operating a polarizing filter.
The lens is constructed with 19 elements in 15 groups. Of these four are AD-glass (Anomalous dispersion) elements. These are used to eliminate chromatic abberations and distortion. High-quality multi-coatings increase transmittance and reduce flare to preserve contrast. A circular aperture keeps the defocused image of point light sources outside the depth of field round between f/2.8 and f/5.6. The filter thread is 77mm. The lens is pretty heavy at 1340g but that is about the same as equivalent lenses from the competitors. The 1.2m closest focusing distance however is the best in the class and makes the lens better for close portraits etc.
6. Optical Performance Different wavelengths of light come into focus at different planes. This effect is know as Chromatic aberration and can cause a "rainbow" halo around points of light and reduced sharpness. The Anomalous Dispersion (AD) glass, used in four elements of the lens, virtually eliminates the effects of lateral and longitudinal chromatic aberration, providing increased sharpness and extremely accurate colour rendition.
The tables below summarize my findings when shooting a resolution chart with the
lens to test its optical quality. These results are obtained using the digital
Minolta Dynax/Maxxum 7D. Please note that this camera uses a reduced image
circle of 1.5. Thus the lens qualities at the far corners of the 35mm film frame
are not tested. The ratings are as follows:
70-200mm f/2.8 Apo G (D) SSM with 1.4x Tele converter Apo (D) @ 200mm
Overall the AF 70-200mm f/2.8 Apo G (D) SSM lens delivers excellent image quality. The
performance wide open is very good and even better stopped down to f/5.6 which
seems to be the aperture with the best optical performance. But I would not
hesitate to use it wide open either. If you decide to stop all the way down to f/32,
although I don't know why you would with this lens, the optical quality suffers. The optical quality of this lens is actually about the same as the AF 200mm f/2.8 Apo G (N) which is known as one of best Minolta lenses around. If you attach the 1.4x Teleconverter Apo (D) you loose a little bit of sharpness but not much. Stop down one more stop to get to the best aperture at f/8. But like without the converters, I would not hesitate to use this combination wide open either. Illumination is even on the whole image with the reduced image circle of the Dynax/Maxxum 7D and not noticable on a full frame camera. Geometric distortion is negligible. The graphs below are the Minolta MTF graphs for the lens.
The graph 7. When the image is out of focus The word Bokeh is of Japanese origin and relates to the fashion in which the out-of-focus areas of the image are rendered. A sharply focused subject set against a pleasingly silky smooth background characterizes a good bokeh. The transition from in-focus to out-of-focus should occur gradually. A large number of aperture blades give a more circular opening when the lens is stopped down, but this in itself is not sufficient to give a good bokeh. Another feature of the lens that affects bokeh is the degree of spherical aberration correction. Spherical aberration is when the rays of light from the middle and from the outside edges of a lens do not focus to exactly the same point. The 70-200mm f/2.8 Apo G (D) SSM shows a very pleasing image rendition. The background blurring attained by the lens is creamy and silky smooth, entirely up to the bokeh of the very best performers.
8. Flare and ghosting The photographer should play an active role in controlling lens flare. The absence of a lens hood contributes to lens flare, so you should always use a lens hood. The narrow field of view of a telephoto lens means that you can use deep hoods that very effectively cut out glare and reduce flare. So far I have not noticed any problems with flare or ghosting when using the 70-200mm F2.8 Apo G (D) SSM lens. What causes flare Zoom lenses have always been susceptible to excessive ghosting, often combined with a moderate resistance to flare as well. Despite sophisticated multi-coating treatment of the glass surfaces, unwanted internal reflections are prone to occur. Since light reflects off glass surfaces, lens flare usually increases with the number of glass elements in the lens. The problem is compounded with backlit subjects.
9. Summary and Conclusions This lens has the excellent optics, build quality and excellent autofocus that is to be expected from a top of the line Minolta G lens. The close focusing distance, the nice lens hood with the polarizing filter window and the smooth manual focusing all comes as a bonus. All I can say is that this has to be one of the finest lenses ever produced by Minolta. Pros
Cons 10. Magazine lens tests
|
_ssm.gif)
_ssm_optics.gif)
_ssm_MTF.gif)
