Importing raw files - fisheye lense, differences with jpeg

[jes-rome]

Hello everybody,

A couple of months ago I sold my Canon 5Ds and switched to a Canon M6 mk II because of weight and size. I kept, though, my EOS Fisheye zoom 8-15 mm, which I am actually using a lot with the M6.

I have noted - in particular when using the 8-10 mm focal lengths - a difference between the jpeg and raw files when importing into Affinity, which I do not understand and for which I wonder whether there is a way to resolve this in Affinity (Mac desktop, 1.9.3).

Have look to the attached photo (the M6 takes both the jpeg and the raw photo at the same time). On the right, the Mac "Preview" of a photo taken with 10 mm. On the left, the resulting import of the (same) raw file into Affinity. Beside the black areas in the corners, the raw file is missing parts of the scene wrt to the jpeg. BTW, "previewing" the raw file (with Preview) the appearance is like the jpeg version.

Can somebody explain me why there is this difference ? Anything I can do to correct it ?

Many thanks + greetings from Rome - Juergen

 

[John Rostron]

The 'raw' image on the  left shows what the camera has taken. The image on the right is is an interpretation of the raw file by the jpeg processor in the camera, which creates a jpeg embedded in the raw file as well as the separate jpeg file. he preview program will use this embedded jpeg file.

33 minutes ago, jes-rome said:

the raw file is missing parts of the scene wrt to the jpeg. BTW, "previewing" the raw file (with Preview) the appearance is like the jpeg version

I have been told that some raw files actually include some pixels outside the displayable raw image.  I would guess that these have been used to create the jpeg file, which accounts for this.

John

[jes-rome]

Hi John,

Many thanks for the feedback! I wasn't aware that there was a jpeg embedded in the raw file, but that explains a lot ...

Now, I played with the Lens Correction settings of the raw file. Indeed, Affinity applies the (correct) lens profile for the Canon EF 8-15mm lens (but the M6 is not full frame ?!). De-selecting this, plus 'Remove Lens Vignette' set to about 15 % yields the same as the embedded jpeg, maybe even some pixels more. 

Juergen

[IanSG]

Have a look at Fast RawViewer if you want to preview the RAW files themselves rather than the embedded jpegs.

[David in Яuislip]

@jes-romeA fascinating lens, would you mind uploading the raw file, I'd like to play with the lensfun parameters to see if it can be fixed. Cheers

[jes-rome]

Sure! Have fun  

IMG_0779.CR3

[jes-rome]

1 hour ago, IanSG said:

Have a look at Fast RawViewer if you want to preview the RAW files themselves rather than the embedded jpegs.

Funny, with that tool the raw file looks like the jpeg version of it .. so may I say it is Affinity that "works" on the raw photo ups import ?! 

[IanSG]

1 hour ago, jes-rome said:

Funny, with that tool the raw file looks like the jpeg version of it .. so may I say it is Affinity that "works" on the raw photo ups import ?! 

FastRawViewer allows you to process the viewed image by adjusting exposure, contrast, sharpening etc - I can't remember what the defaults are, but I'm not surprised you're seeing something like the jpeg version.  The idea is to give you a better idea of what post processing will do for you.

[David in Яuislip]

1 hour ago, jes-rome said:

Sure! Have fun  

Oh I did. I found the lens data in https://github.com/lensfun/lensfun/blob/master/data/db/slr-canon.xml
and removed the distortion & vignetting info. Not exactly earth shattering but it'll save a couple of clicks

Canon8-15.xml

[jes-rome]

11 minutes ago, David in Яuislip said:

Oh I did. I found the lens data in https://github.com/lensfun/lensfun/blob/master/data/db/slr-canon.xml
and removed the distortion & vignetting info. Not exactly earth shattering but it'll save a couple of clicks

Canon8-15.xml 970 B · 0 downloads

Indeed, it does! Many thanks!