Vignetting on DNG

[Big John]

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Hi all,

 

Have seen from time to time that DNG files show marked vignetting - indeed the corners of the frame are all backed out. JPEGs are fine so I assume corrected by in-camera software.

 

Just keen to understand this a bit more pls. What causes it, why only occasional?

 

Thanks.

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[LD_50]

Aperture, focal length, lens used, more/less noticeable subject matter.

 

Vignetting is a property of the lens (for a given sensor size).

[pico]

Have seen from time to time that DNG files show marked vignetting - indeed the corners of the frame are all backed out.

 

How are you viewing the DNG files?

.

[250swb]

Yes, in camera corrections sort the vignetting out with a JPEG, but you must be viewing the dng files with corrections turned off. So you need to find some buttons to press in your software.

[ramarren]

When shooting with the shortest focal lengths and the SL24-90, when viewing raw files with a raw converter that does not support the lens corrections, the lens will be seen to have a noticeable amount of barrel distortion and the corners are quite dark. The lens correction parameters injected into the raw file correct these flaws with compatible raw converters automatically (like Lightroom and the Camera Raw plugin in Photoshop).

 

The lens was designed to image this way in order to give the best performance, balancing the optical design with image processing. The marked 24mm is actually a bit shorter than that optically so that the corrections net a full, proper 24mm FoV.

[Big John]

How are you viewing the DNG files?

.

  

Yes, in camera corrections sort the vignetting out with a JPEG, but you must be viewing the dng files with corrections turned off. So you need to find some buttons to press in your software.

  

When shooting with the shortest focal lengths and the SL24-90, when viewing raw files with a raw converter that does not support the lens corrections, the lens will be seen to have a noticeable amount of barrel distortion and the corners are quite dark. The lens correction parameters injected into the raw file correct these flaws with compatible raw converters automatically (like Lightroom and the Camera Raw plugin in Photoshop).

 

The lens was designed to image this way in order to give the best performance, balancing the optical design with image processing. The marked 24mm is actually a bit shorter than that optically so that the corrections net a full, proper 24mm FoV.

Many thanks everyone. I tend to use Google Picassa for initial download of files then play in LR. So I see the vignetting in DNG files viewed in Picassa. I know.....bet I am only person here using Picassa for viewing Leica SL files

 

The explanations above make sense to me, thanks all.