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Author Topic: DXO PL4 lens modules  (Read 797 times)

Rhossydd

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DXO PL4 lens modules
« on: November 09, 2020, 05:35:59 am »

Is there any way to force PL4 to use a specific lens module on an image ?

I've got a lot of shots taken with a Samyang 14mm on Canon 5D ii & iv. This is the fully manual lens, so no EXIF data on the lens for PL4 to use, but I can't find a way to use the lens module that they have for the AF version of the lens.

I'm also seeing PL4 try to use a wrong module for a lens it doesn't recognise. (Tamron 45mm instead of Canon EF45mm TSE)
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Rhossydd

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Re: DXO PL4 lens modules
« Reply #1 on: November 11, 2020, 11:07:57 am »

A priceless reply from their tech support on this issue;

"Unfortunately it is not possible to assign a "similar" or "identical" module to an image. The automatic corrections of our software are based on the correct measurement of each individual component, which is why there are now well over 60,000 different DxO modules. We also take no values ​​from previous measurements when developing the modules. Each module is developed individually in a very complex process.

Even if the manufacturers say that they are identical models, there are always differences, even if only marginally. DxO's aim, however, is to achieve a perfect result, which is why we also make this effort.

If you are using a manual lens, we can't run this process of calibration with thousands of testshots, we depend on a minimum of  EXIF - information for this process and to offer a proper optical module. In such a case we can only invite you to use manual corretions offered in PhotoLab.

Tamron 45mm instead of Canon EF45mm TSE:
If a lens is not suported, PhotoLab is trying to find a lens with similar length from the Exif data. It is then up to you to decide, if this suggestion is giving good corrections or if you prefer to use manual corrections instead. In that case you should remove the module. "


In other words we won't let you apply a module of your choice, but we'll offer a choice if we choose to. (even though it may be significantly worse)
« Last Edit: November 11, 2020, 05:16:11 pm by Rhossydd »
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Rhossydd

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Re: DXO PL4 lens modules
« Reply #2 on: November 13, 2020, 11:30:30 am »

The plot thickens;

Having now spent more time trying out PL4 I'm seeing a significant bug; it doesn't read exif lens data correctly.
It's bizarre that it's suggesting downloading modules for lenses that I've never owned or shot with. Also displaying the wrong information in the metadata panel.
All other software I use (LR, CO, Affinity, DPP) gets it right, so definitely a PL4 problem.

If it's using it's incorrect data to load the wrong lens modules, but there's no confirmation of that, any corrections will be wrong. Which further makes a nonsense of the tech support reply I quoted above.



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kirkt

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Re: DXO PL4 lens modules
« Reply #3 on: November 15, 2020, 11:14:18 am »

The AF version of the lens has a module for the 5DII, III and IV (see screenshot of DxO's website).  To feed DxO PhotoLab the data it needs to load the module you want to use, you can edit the exif data in the raw file using EXIFTool.  When you invoke EXIFTool with the following command, it should make a backup copy of the raw file with the prefix "_original" so that the original CR2 file is not being altered.  The command line text is:


Quote
exiftool -canon:lenstype#=103 -focallength=14.0mm -lensmodel="Samyang 14mm F2.8 IF ED UMC AE Aspherical" -minfocallength=14mm -maxfocallength=14mm rawfilename.CR2

To check your work and see if the changes were made successfully, you can issue the command:

Quote
exiftool -a -G1 -lensmodel -fnumber -focallength -lenstype rawfilename.CR2

I went onto imaging-resource.com and downloaded a 5DIV file shot with a 24-70 lens at 50mm - I changed the EXIF data using the above command and opened the modified CR2 file in PhotoLab3 - it prompted me to download a missing module and the Samyang was listed.  I downloaded it and the module was applied to the image.

In the above command, the tag "-canon:lenstype#" refers to a numerical code for the specific lens - the list of lenses and their corresponding numbers can be found here:

https://exiftool.org/TagNames/Canon.html#LensType

103 is the Samyang 14mm AF lens.

Maybe this will get you where you want to be with those images that can benefit from DxO's lens correction.  You can apply this command to a batch of images - just put them all in the same directory and use the filename "*.CR2" where the "*" is the typical wildcard character.

Obviously you would want to test this on a duplicate file that can be modified and potentially destroyed to see if it works without the risk of messing up important files.

Kirk
« Last Edit: November 15, 2020, 11:26:00 am by kirkt »
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Rhossydd

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Re: DXO PL4 lens modules
« Reply #4 on: November 16, 2020, 04:47:38 am »

Thank you VERY much for making the effort to give such a detailed and helpful reply. It all works well here. A pity that DXO tech support couldn't have been as helpful.

I had tried using exiftoolgui to make exif data changes, but PL4 still hadn't recognised the lens. I can now see that PL4 is using the 'lenstype' tag, which I hadn't been able to change, rather than the basic focal length and manufacturer data that I did change.
I don't think exiftoolgui makes this tag editable, which is what had stumped me. (FWIW all other gui exif data editing tools I tried didn't offer this option either)

For those that follow and don't like messing with command line programs. The most user friendly way to handle this is by creating a folder, putting exiftool into it (rename to exiftool, not exiftool(-k) ), the create a short cut to the program in the same folder, the command line can then be easily added to the short cut's target properties. Then you can just run the program on any and all files copied to the folder, then move the changed files back where you want them.

I'll probably do this to all new shoots with this lens. Going back to convert every other instance of using this lens in the past eight years won't happen quickly with over two thousand images in dozens of different folders.

I'll now go and test some more examples to see how well PL4 handles this lens. At first looks it would seem to be not any better than Lightroom, but other images might show more benefits than the first trials.

I still have big reservations about using PL4 when other lenses that PL4 should know aren't being correctly identified. Apart from the fantastic noise reduction there aren't a lot of compelling reasons to add it to my software library here, but lots of tedious little annoyances that make working with it frustrating, eg always starting with a constrained crop ratio and the rather coarse adjustment sliders, there's others too but that may just be not knowing the program well enough yet. It may be that it will be useful if just regarded as a noise reduction plug-in to Lightroom.

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kirkt

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Re: DXO PL4 lens modules
« Reply #5 on: November 16, 2020, 07:06:34 pm »

You're welcome!

Kirk
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IanSeward

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Re: DXO PL4 lens modules
« Reply #6 on: December 10, 2020, 01:11:46 pm »



I still have big reservations about using PL4 when other lenses that PL4 should know aren't being correctly identified. Apart from the fantastic noise reduction there aren't a lot of compelling reasons to add it to my software library here, but lots of tedious little annoyances that make working with it frustrating, eg always starting with a constrained crop ratio and the rather coarse adjustment sliders, there's others too but that may just be not knowing the program well enough yet. It may be that it will be useful if just regarded as a noise reduction plug-in to Lightroom.

You can create a preset with whatever tools/settings that you like applied and then set that in the preferences to automatically apply when you open a raw image. I guess you have the DXO - Standard currently set in preferences. You can customise the UI pretty much however you want in DXO-Photolab 4 Elite.

Ian
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Isleofgough

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Re: DXO PL4 lens modules
« Reply #7 on: December 15, 2020, 11:53:29 am »

I have found DXO photo lab far behind Lightroom and Capture one Pro in its support of both cameras and lenses. Cameras that have been out a couple of years frequently don't have support.
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Rhossydd

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Re: DXO PL4 lens modules
« Reply #8 on: December 15, 2020, 05:32:49 pm »

I have found DXO photo lab far behind Lightroom and Capture one Pro in its support of both cameras and lenses.
Whilst camera body support is certainly important. One of the really good things about LR is that lens support is really a non-issue. Adobe lens profile creator allows users to profile any lens quite easily and effectively.
DXO may claim that their systems will give better results, which maybe the case at the extreme limits when the lens is supported and correctly identified, but ALPC results will be so close most users wouldn't need anything better. However as DXO fails to correctly identify lens metadata and then will only allow incorrect profiles to be used, it's end result may be worse than LR's profiles and it's ability to set your own choice.
It's mess they should sort out.

I'm not sure Ian's suggestion of using presets to change tool's default behaviour is a good feature and isn't documented.

 Maybe they'll sort out the bugs and crank up the speed in future, but after a lot of evaluation I'm not getting the credit card out for this one.
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