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Sony FE 200-600mm f/5.6-6.3 G OSS - Review / Test Report - Analysis |
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Lens Reviews -
Sony Alpha (Full Format)
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Page 2 of 3
Distortion
The Sony FE 200-600mm f/5.6-6.3 G OSS has a somewhat unusual distortion characteristic. Very often, there's a switch between barrel distortion at the short end and pincushion distortion at the long end of the zoom range but in this case, there are medium pincushion distortions around the 1.5% mark throughout the zoom range.
With activated image auto-correction, the distortions are perfectly corrected as you can see below.
Vignetting
The RAW vignetting is about typical for a super tele zoom lens. At maximum aperture, the light falloff is visible without being extreme within the full format scope. The vignetting varies between 1.1EV (f-stops) at 200/400mm and 1.5EV at 600mm. Stopping down by 1 f-stop dissolves this mostly.
With activated image auto-correction, you won't notice any significant light-falloff at any setting.
MTF (resolution)
The Sony FE 200-600mm f/5.6-6.3 G OSS shows a pretty impressive resolution characteristic for such a lens. At 200mm and 400mm, the broader center sharpness is great at f/5.6 (f/6.3) and the outer image region is easily on a very good level. Given the slow max. aperture and due to diffraction, it isn't overly surprising that there's no increase in quality anymore when stopping down. The situation is slightly different at 600mm. The center sharpness is still impressively high but the border and corner quality is reduced. Stopping down to f/8 or f/11 improves the outer image field but there isn't too much in it and the center is limited by diffraction once again anyway.
The field curvature is low. The centering quality of the tested sample was Okay with a slight unevenness showing up at the long end.
Please note that the MTF results are not directly comparable across the different systems!
Below is a simplified summary of the formal findings. The chart shows line widths per picture height (LW/PH) which can be taken as a measure for sharpness.
If you want to know more about the MTF50 figures you may check out the corresponding Imatest Explanations
Chromatic Aberrations (CAs)
Lateral CAs (color shadows at the image borders) are somewhat more pronounced. The CAs peak with an average pixel width of ~2.1px at 200mm f/5.6. The issue is not quite as high at other settings but varies around 1.5px. Lateral CAs can be removed fairly easily via auto-correction so it's not really a disturbance.
Bokeh
Super-tele zoom lenses tend to have a rather busy bokeh specifically with respect to the rendering of out of focus highlights. So how does the Sony FE 200-600mm f/5.6-6.3 G OSS manage in this respect?
It's better than most actually. The bokeh highlights aren't perfect but while there is a bit of outlining, it's not extreme. The inner zone of the discs is just slightly uneven. The circular shape remains intact when stopping down to f/8 and even f/11. No less than 11 aperture blades surely help here.
The shape of the highlights tends to deteriorate towards the image borders - this is due to mechanical vignetting. However, the near-perfect zone is bigger than on most lenses and even the corner highlights aren't overly unpleasant with their ellipsoid shape. As usual stopping down corrects the outer highlights and they are pretty much restored at f/11.
The general rendition in the focus transition zones is very smooth both in the background (shown to the left below) as well as in the foreground (to the right).
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