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I have several Sony ILCs. I usually shoot to JPG.

I post-process in Lightroom.

I know in principle that lens correction profiles are useful for RAW images. I can't tell if or when they should be applied to JPG images: Is there a definite way to determine whether the camera has applied its own lens correction to JPGs? (Short of running tests, which may be ambiguous with quality glass ;)

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Many modern ILC cameras are capable of applying corrections but those features are optional. You usually have menu options to enable different things such as Lateral Chromatic Aberration Removal, Vignetting Compensation and Distortion.

Enable those you want in-camera and do the rest in Lightroom. Sometimes the camera does an very good job, but even so it can slow down throughput and buffer depth. The one I recommend never to enable in-camera is distortion correction because it affects framing and you will lose image parts. It is better for you to decide if a particularly image has enough around edges to remove distortion without compromising composition. Also, on some subjects, distortion is simply less noticeable but image processing to do so will always reduce image quality.

Also you can do it twice if necessary. A camera may remove chromatic aberrations but leave some in and you can have Lightroom clean up (some) of the rest.

A few cameras do some processing that cannot be disabled but this is mostly on fixed-lens cameras. You can always shoot RAW+JPEG and look at differences yourself. Just use tests that stress different corrections.

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How can I tell if my Sony ILC is applying lens corrections to in-camera JPEGs?

Ask it.

The chances are almost certain the information you want is contained within the EXIF information embedded in the image file. If Adobe ignores the lines, usually in the maker notes section, that tells you what options were turned on and off when you shot the image, use another application to view the more complete EXIF info. IrfanView and EXIFTool are both popular free apps that will show you much more of the EXIF info contained in an image file than Adobe products will.

What EXIF fields will inform us of corrections that have been applied to the file in question? E.g., I queried a JPEG and I see things like 'Distortion Corr Params Present: Yes', and 'Distortion Correction: None'. Plus there are 'Distortion Corr Params', 'Vignetting Corr Params', 'Chromatic Aberration Corr Params' ... so it appears there are a lot of correction data present, but not applied? And is it obvious how to tell Lightroom to apply these parameters?

When it shows 'yes' for 'Distortion Corr Params Present' it means the camera had a correction profile for that lens available when the image was shot. It does not mean that the correction profile data is included in the image file created by the camera. It also does not mean the correction parameters were actually used to process the raw data from the sensor when producing the jpeg in -camera. 'Present' only means it was in the camera's data storage at the time and available for use at the time the photo was taken.

"Distortion Correction: None' means that even though there was an appropriate profile available at the time the image was captured, it was not applied to the raw data from the sensor when it was converted to a jpeg by the camera's internal processing.

Since the lens correction profile itself is not included in the image file, to apply correction after the fact using Lightroom or any other app, the application needs to have a correction profile for that camera/lens combination available within the application's data files. The correction profile used by the camera and the one used by the post processing application may or may not be the same or even similar. It all depends upon the source of each profile and whether the manufacturer of the camera and lens provide those profiles to the developers of third party products such as Lightroom.

  • What EXIF fields will inform us of corrections that have been applied to the file in question? E.g., I queried a JPEG and I see things like Distortion Corr Params Present: Yes, and Distortion Correction: None. Plus there are Distortion Corr Params, Vignetting Corr Params, Chromatic Aberration Corr Params ... so it appears there are a lot of correction data present, but not applied? And is it obvious how to tell Lightroom to apply these parameters? – feetwet Aug 11 '17 at 14:31
  • The problem with LR is it ignores a lot of the EXIF info located in the non-standardized 'maker notes' section. The names of the EXIF fields in the maker notes section will be specific to a particular manufacturer, a specific camera model, or even a particular firmware version for that model. Because they are non-standardized fields the manufacturer can put whatever they want there. – Michael C Aug 11 '17 at 20:03
  • So ... are the "correction parameters" I found non-standardized EXIF info? Does their presence mean that those corrections were applied by the camera? Or what software can apply or unapply those parameters? – feetwet Aug 11 '17 at 20:12
  • @feetwet what application did you use to query the JPEG referenced in your above comment? – Michael C Aug 11 '17 at 22:14
  • "Or what software can apply or unapply those parameters?" The actual correction profiles aren't included in the EXIF info, only whether you used them or not when the photo was taken. The camera stores the profile for each lens in its memory (assuming either you have loaded it or the camera came with it preloaded). If you use an application to apply correction after the fact a profile for that lens/camera combination must be contained in the app. The two profiles (one that the camera has, the other that the app has) may or may not be the same. It just depends on where each profile came from. – Michael C Aug 11 '17 at 22:20

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