Lens profile f. Canon G5X mk II

[thomaso]

I am missing a lens profile for the Canon Powershot G5 X Mark II and its 8 - 44 mm lens.

I placed the Github lensfun "compact-canon.xml" into the APhoto lens folder but it seems not to contain the profile.

I convert the ".CR3" RAW files with Adobe DNG Converter, they open without distortion in macOS quicklook, preview.app and adobe apps. Does that mean there is a lens profile on my mac somewhere – if yes, where, and can I use it in APhoto? – if not, where can I get the missing lens profile for APh?

[Dan C]

Hi thomaso

11 hours ago, thomaso said:

I placed the Github lensfun "compact-canon.xml" into the APhoto lens folder but it seems not to contain the profile.

I can confirm this .xml contains the required profile for the G5 X, but unfortunately not for the G5 X Mk 2 -

11 hours ago, thomaso said:

I convert the ".CR3" RAW files with Adobe DNG Converter, they open without distortion in macOS quicklook, preview.app and adobe apps. Does that mean there is a lens profile on my mac somewhere – if yes, where, and can I use it in APhoto? 

There are a few factors at play here - firstly when previewing the file in Quicklook/Preview you will be viewing an embedded JPEG which has lens correction pre-applied by the camera. When opening it in Adobe apps the Lens will be detected and Correction applied. Unfortunately however this correction cannot be 'read' by Affinity from the Adobe file, so you cannot find/use this file on your Mac in conjunction with Affinity.

11 hours ago, thomaso said:

if not, where can I get the missing lens profile for APh?

You may be able to find a custom .XML file generated by another user elsewhere on the web, however the accuracy of this cannot be confirmed. For support in Affinity we are awaiting a Lensfun update, which we have no control over. My apologies!

[thomaso]

3 hours ago, Dan C said:

when previewing the file in Quicklook/Preview you will be viewing an embedded JPEG which has lens correction pre-applied by the camera. When opening it in Adobe apps the Lens will be detected and Correction applied

Thank you for the infos. I understand your hint with the embedded JPG. Can you also give me a hint how it works for the Adobe apps? I haven't downloaded any profile for this camera and use quite 'old' Adobe image editor app versions which don't do any updates any more. So, I wonder how these older apps get the new profile data. Does the current DNG converter app write the lens profile into the DNG file which gets read by my older Adobe image editor apps?

Do you know whether the Canon app ("digital photo professional" v.4) might contain the lens profile in a file format that I can excerpt and use for APh? If you like I update an installer of this app for verification/investigation.

[Dan C]

16 hours ago, thomaso said:

So, I wonder how these older apps get the new profile data. Does the current DNG converter app write the lens profile into the DNG file which gets read by my older Adobe image editor apps?

Unfortunately I'm not very knowledgeable in regards to the older Adobe products, so I'm hesitant to comment here. In regards to DNG conversion, from a quick Google search it doesn't appear as though converting the file embeds any new data, or a lens profile - but again I may be wrong here.

16 hours ago, thomaso said:

 Do you know whether the Canon app ("digital photo professional" v.4) might contain the lens profile in a file format that I can excerpt and use for APh? If you like I update an installer of this app for verification/investigation.

Unfortunately it's very unlikely, borderline impossible, to extract any such data from another app to use within Affinity, my apologies.

[thomaso]

17 hours ago, Dan C said:

In regards to DNG conversion, from a quick Google search it doesn't appear as though converting the file embeds any new data, or a lens profile - but again I may be wrong here. 

Thanks to your previous hint I searched for a lens profile for the G5XmkII camera and run into this info about embedded lens profiles within RAW files of particular cameras:

"(...) some cameras embed the lens profile in the raw file (along with the image data) and LR applies the lens profile itself in the first stage of processing the raw data."
https://www.dpreview.com/forums/post/63000384

A check in LR confirms for the G5XmkII to have the lens profile integrated (which becomes auto-activated, regardless of the profile checkbox):
"This raw file contains a built-in lens profile for distortion and chromatic aberration. The profile has already been applied automatically to this image."

That would mean that even the Canon app doesn't have nor need a separate lens profile file to apply distortion correction when developing such a .CR3. That makes me wonder whether there will ever come a lens profile in lensfun for the G5XmkII. Also, since Serif still works on .CR3 import compatibility, I wonder whether you might want me to upload a .CR3 in particular from this camera model, if yes just post a upload link – or download some from this gallery (which can be filtered by focal lengths):
https://www.dpreview.com/sample-galleries/6009098889/canon-powershot-g5-x-ii-sample-gallery/

 

[v_kyr]

3 hours ago, thomaso said:

That would mean that even the Canon app doesn't have nor need a separate lens profile file to apply distortion correction when developing such a .CR3. That makes me wonder whether there will ever come a lens profile in lensfun for the G5XmkII.

Libraw and Lensfun (what APh is based on here) don't use the embedded lens distortion parameters which are stored in such raw files. Instead lensfun relies on own data from lens calibration. See ...

• Lensfun lens calibration
• Create lens calibration data for lensfun
• Lens calibration for Lensfun
• etc.

Thus you have to wait until somebody with a G5X mk2 performs an accordingly lens calibration for that cam and provides the data results for the lensfun project db.

So far the only other option you actually have here with APh on MacOS is, to update your MacOS version to one which supports your cam RAWs and then switch in APh to use the Apple RAW engine instead.

[walt.farrell]

2 minutes ago, v_kyr said:

Thus you have to wait until somebody with a G5X mk2 performs an accordingly lens calibration for that cam and provides the data results for the lensfun project db.

Or, one can follow the instructions in the first link you posted (to request addition of a specific camera/lens), or in the next link(s) to perform a calibration oneself.

[v_kyr]

7 minutes ago, walt.farrell said:

Or, one can follow the instructions in the first link you posted (to request addition of a specific camera/lens), or in the next link(s) to perform a calibration oneself.

However, all that falls finally into the category "wait until", since there isn't yet any lensfun data for that cam.

[walt.farrell]

22 minutes ago, v_kyr said:

However, all that falls finally into the category "wait until", since there isn't yet any lensfun data for that cam.

Following the instructions in your second link you can generate it yourself, as I understand it. But it involves a fair amount of work.

[thomaso]

Thank you, v_kyr and Walt, I had recently read about the lensfun project and its options – I just haven't been aware that lens profile embedding is common for a while, I thought it might be rather a new way of handling lens profiles and for newer camera models only. Good to know that a profile possibly might be created one day, regardless of its embedded version. Also good to know that Apple has profiles in its macOS, I never experienced that before. (Though I still avoid a macOS upgrade for other app compatibilty reasons). So I just wait. (Actually, after some hours with Affinities develop persona, I noticed I prefer to continue developing RAWs in an app with more DAM features).

[v_kyr]

42 minutes ago, walt.farrell said:

Following the instructions in your second link you can generate it yourself, as I understand it. But it involves a fair amount of work.

Yes you can calibrate and profile yourself. And yes some amount of work is involved to do so, but that's the way to go in order to have lensfun support for certain cam & lens combinations.

[v_kyr]

48 minutes ago, thomaso said:

Also good to know that Apple has profiles in its macOS, I never experienced that before.

Well your cam is supported by Apple since MacOS Mojave (look here), though honestly I'm not sure if that alone (just for direct G5X ii RAW support) would justify an OSX update for you, especially as far as everything else works fine actually on your current used MacOS version.