Photo Jottings

Here’s a brief look at the Minolta AF 70-210mm F/3.5-4.5 zoom lens.  Scroll down for the main review.

Box and lens, included hood not shown

Fully extended, including focus extension

Fully drawn in

Front element

Backside mount

Only the Sony A900 was used for this review, (except for the normal macro shot with the A700).  For a better understanding of terms and methods used in this review, go here.

If you want to know how the corners look using an APS-C camera, just check out the mid-level crops, they were taken at the approximate APS-C corner area.

Fit and finish are good, but it does have a lot of plastic, like the Sony 75-300mm F/4.5-5.6 lens.  It has a metal mount and the ability to use 55mm filters, also like the older F/4 model.  The color and sheen, black satin, is the same as the later models of Minolta and Konica Minolta lenses, and most of the newer Sony lenses.

The zoom action is somewhat easy to turn in my opinion, and doesn’t holds its position well, so there is some zoom creep, unfortunately, there is no zoom lock.  Focal length index marks come at 70mm, 100mm, 135mm, and 210mm, and the EXIF data matches those lengths.  There’s a blue “—-M—-” with a line in the focus distance window covering the distance of close focus, 1.1m to 1.5m, which means that’s the distance where you’ll get the largest macro size, (when zoomed in to 210mm).

In the box comes the lens and hood, with front and rear caps.  My used copy was missing the hood, that’s why there is no picture of it in the product shots above.

Focusing.  This lens auto-focuses pretty quickly and accurately.  Take note; the front filter ring rotates while auto-focusing, so watch your polarizers and grads.  Manual focusing is performed by turning a ring at the end of the barrel, it’s rubber, and turns easily with a finger.  If you want infinity, crank it over to the hard stop and it will be right.  Focusing takes a little over 1/3 of a turn from close up, to infinity.  Also, focus extension adds 14mm to the length.

Lens flare/ghosting.  Below average control for a telephoto zoom by today’s standards.  Veiling glare is very strong, so prepare to block the sun or other super-bright light source with your hand to keep the contrast up in your shots, if the sun isn’t actually in the shot.  Look for multi-colored ghosts and arcs at all focal lengths.  The older Minolta 70-210mm F/4 beercan is much better at controlling flare and ghosting than this lens.

Color fringing (CA).  Average control.  Look for minor amounts of lateral color fringing (magenta) towards the short end, and heavy amounts (green and magenta) near the long end.

Bokeh.  Good overall.  Harsh wide open at the short end, but smooths out a stop down.  The long end is smooth at all apertures.  Look below for sample crops.

Color.   Same as other Minolta AF lenses.

Close up filter.  N/A

Coma.  None.

Regular filters cause very minor additional light fall-off on full frame cameras when the aperture is fully open.

Filter size is 55mm.  This is Sony’s most popular filter size, other Sony lenses sharing this size are: 50mm F/1.4, 50mm F/2.8 macro, 100mm F/2.8 macro, 18-70mm kit lens, 55-200mm and the 75-300mm.  The Minolta AF 70-210mm F/4 lens also uses this size.

Distortion.  You’ll notice very mild barrel distortion at 70mm, and moderate to heavy pincushion distortion at 210mm.  With an APS-C camera, there is almost no distortion at 70mm, and light to moderate pincushion distortion at 210mm.  Check out the full frame cropped samples below.

Distortion examples directly below.

70mm, nearly flat.

210mm, strong pincushion distortion.

 

Aperture/focal length guide.

 

 

Bokeh is harsh at 70mm, F/3.5, but smooths out nicely at F/5.6.  Towards the long end, the out of focus background highlights are rendered smooth at all apertures, although the F/5.6 crop looks less smooth than the F/4.5 crop, in reality, there isn’t any difference with bokeh in the centers when zoomed towards 210mm.   I see some “swirling bokeh” when the aperture is wide open, and centered on certain subjects, but stopping down slightly gets rid of it.

 

See the crops below.  Light fall-off or corner shading is very heavy at both ends at the largest aperture, especially when focused close.  Stopping down helps tremendously.  With an APS-C camera, the dark corners would be much less noticeable.

Center sharpness. 

Below are crops from the image centers at 70mm.

Center sharpness is a little soft when used wide open at 70mm, however, stopping down to F/5.6 sharpens things up.  I used the stamp subject this time so I wouldn’t have to deal with the effects of heat shimmer, which is a big summertime problem in Tucson, Arizona, especially at longer focal lengths.  The distance from the lens to the subject at 70mm was about 11′ or 3.35m.  Go here to learn about how big the stamp is.

 

At the mid-section, (APS-C corner area) sharpness is awful at F/4.5 and doesn’t get much better by stopping down.  There is some light fall-off, which lowers the exposure in this area, but sharpness doesn’t look any better when stopped down, (unless down to F/16-22), see the corner crops below.

 

Below are the corners at 70mm.

 

The 70mm corner crops are poor unless stopped down to F/16-22, but then diffraction softens the centers, so there is no real advantage in doing that.

Center sharpness at 210mm. 

Below are crops from the image centers at 210mm.

Center sharpness at full telephoto is a little soft at F/4.5, but closing the aperture to F/8-11 sharpens things up nicely.  The crops at 210mm are a little darker and closer than the 70mm corps.  I used a different exposure setting and distance, so don’t compare them directly with each other.  The distance from the front of the lens to the stamp is about 26′ or 7.9m.

 

At the mid-section, (APS-C corner area) things look fairly sharp, although the crops don’t really seem to sharpen up any by closing the aperture.

 

Below are the corners at 210mm.

 

The corners have low contrast, and don’t respond much by stopping down.  Also, notice the heavy lateral color fringing, which doesn’t go away by closing the aperture.  The exposure differences as compared to the other crops are caused by light fall-off.  All crops have the same exposure values.

Let’s check out the macro capabilities of this lens.

As close as you can get. F/8. click for larger image