Hi,

Am 15.11.2017 um 12:28 schrieb Roman Lebedev:
On Wed, Nov 15, 2017 at 2:14 PM, Heiko Bauke <heiko.ba...@mail.de> wrote:
[...]
Contrary to the common believe that in-camera
corrections are applied to JPEGs but not to the RAW file, in-camera lens
correction in the EOS-1D X Mark II is applied to RAWs only.  See
https://snapshot.canon-asia.com/article/en/eos-5d-mark-iv-lens-aberration-correctiona-close-up-look-part-1

Can you quote that part where it says what you think it says?
I don't see anything there about modifying the raw files.

the article is about in-camera lens correction. Lens corrections are stored in the image data, it's not about storing meta data for lens correction in post processing. Do not be confused by the fact that there is also a software tool provided by Canon that implements the same kind of lens correction algorithms for post processing.

The term RAW file is not included explicitly in the article that I mentioned. It is, however, highlighted that »The Digital Lens Optimizer [...] made its debut as an in-camera feature on the EOS-1D X Mark II. At that time, its effects could not be reflected in real time on JPEG images.« I understand this statement as that the RAW file image data is affected. The camera has a special hardware component to do the heavy math. This would not be needed if just some meta data for lens correction in post would be included into the RAW file.

Furthermore, another Canon article (see https://snapshot.canon-asia.com/article/en/eos-1d-x-mark-ii-in-camera-lens-optimization-for-high-quality-images ) says

»The processing ability of the Dual DIGIC 6 + image processing engines is what makes in-camera image processing possible. They are capable of processing the vast amount of data that is yielded from the 20-megapixel sensor and the continuous shooting speed of 16 fps at a high speed, and achieve in-camera RAW image development and real-time aberration correction. A dedicated IC has been developed and employed to enable the incorporation of different aberration correction features during in-camera RAW image.«

How would you understand »in-camera RAW image development«? It does definitely not refer to the lens correction to the JPEG, because this camera does not have such a feature.

According to https://photo.stackexchange.com/questions/35324/why-does-using-canons-digital-lens-optimizer-double-the-size-of-a-raw-file in-camera lens correction in Canon cameras doubles the RAW file size, because the processed image data is stored in addition to the unprocessed RAW data.


        Heiko

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