M
minibokeh
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Some lenses (example below: Panasonic Leica DG Summilux 15mm f/1.7) have a heavy amount of distortion. Most (all?) m43 cameras store lens correction information as part of their raw files to allow for software-based compensation.
Adobe Lightroom does not provide a choice whether to apply this information - it is always used.
There are several downsides to this:
- Since mathematically the image is warped, some pixels are interpolated and others disappear (loss of actual information). Result: Loss of detail and sharpness, mostly in the corners.
- To achieve "straight" lines, the shape of objects is distorted. This effect is intensified the further away from the center they appear (similar to a fisheye effect).
- The image is cropped to mask "black" areas next to the image border that don't have any information after the transformation.
Many leading raw converters give users a choice whether to use the "correction", or turn it off:
The "good" list includes Iridient Developer (below), DxO 10.0, Capture One 8, Photo Ninja (never applies lens correction), Raw Therapee (not tested myself).
"Bad" raw converters (no choice, people look like Herman Munster): Adobe Lightroom (including 5.7.x), Silkypix (including 6 Pro).
The example below is representative for many images taken with the DG 15mm f/1.7 lens - whenever a person appears near the border of the image, the amount of distortion applied by Lightroom causes visible unnatural alterations (Iridient Developer for comparison):
<a href="https://www.flickr.com/photos/101667287@N08/16172582968" title="Leica-DG-15-f1.7-GM1-raw-converter by Moritz Berger, on Flickr">View attachment 405370"1024" height="768" alt="Leica-DG-15-f1.7-GM1-raw-converter"></a>
Adobe Lightroom does not provide a choice whether to apply this information - it is always used.
There are several downsides to this:
- Since mathematically the image is warped, some pixels are interpolated and others disappear (loss of actual information). Result: Loss of detail and sharpness, mostly in the corners.
- To achieve "straight" lines, the shape of objects is distorted. This effect is intensified the further away from the center they appear (similar to a fisheye effect).
- The image is cropped to mask "black" areas next to the image border that don't have any information after the transformation.
Many leading raw converters give users a choice whether to use the "correction", or turn it off:
The "good" list includes Iridient Developer (below), DxO 10.0, Capture One 8, Photo Ninja (never applies lens correction), Raw Therapee (not tested myself).
"Bad" raw converters (no choice, people look like Herman Munster): Adobe Lightroom (including 5.7.x), Silkypix (including 6 Pro).
The example below is representative for many images taken with the DG 15mm f/1.7 lens - whenever a person appears near the border of the image, the amount of distortion applied by Lightroom causes visible unnatural alterations (Iridient Developer for comparison):
<a href="https://www.flickr.com/photos/101667287@N08/16172582968" title="Leica-DG-15-f1.7-GM1-raw-converter by Moritz Berger, on Flickr">View attachment 405370"1024" height="768" alt="Leica-DG-15-f1.7-GM1-raw-converter"></a>