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Sony FE 70-300mm f/4.5-5.6 G OSS (SEL70300G) - 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 lens has a decent distortion characteristic. At 70mm it shows a medium amount of pincushion distortion (1.5%) changing to very slight pincushion distortions in the mid-range to long end. This is without image auto-correction already - even less so when activating it.
Vignetting
At fully open aperture, the light falloff is around 1.5EV (f-stops) at the extreme ends of the range and a bit less in between. This is visible but within the full format scope, it is also rather common. Stopping down by one f-stop resolves most of the issue.
With activated vignetting correction the light falloff decreases a bit but traces remain at 70mm f/4.5 and 300mm f/5.6.
MTF (resolution)
The resolution characteristic has its highs and lows. The sweet spot of the lens is in the low to mid range. The center quality is excellent at 70mm - even at fully open aperture. The borders are still very good whereas the corners show a weakness at f/4.5 which is resolved at f/5.6 already though. The quality decreases marginally towards the long end of the range although the decrease is negligible till 200mm. The center quality remains fine at 300mm but the outer image region suffers quite a bit at f/5.6. The corners are ... meh. It's best to stop down to f/8 if you want the peak quality at this setting. The far corners remain unimpressive though.
The centering quality of the tested sample was Okayish.
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 can be auto-corrected either by the camera or via Sony's RAW converter. This is a lossless operation so it's a good idea to take advantage of it. However, the Sony lens is generally well corrected with an average CA pixel width of around 1px at 70mm and 1.5px at 300mm at the image borders. Based on a 42mp image size this is pretty good here.
Bokeh
The Sony FE 70-300mm f/4.5-5.6 G OSS is a slow lens. However, thanks to its long range you can still produce a fairly shallow depth-of-field if the main subject remains relatively close. That being said - you shouldnt' expect wonders in terms of bokeh quality in this class and the Sony lens confirms this once more.
The biggest weakness are out-of-focus highlights. The inner zone of the highlight discs show a very rough and unpleasant pattern as you can see blow.
The rendition of blur in the critical focus transition zone is much better. Background blur (left crop below) is just a bit busy whereas foreground blur is very smooth.
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