Any way to update EXIF data?

I have images taken with my Pentax K3 III using a Samyang 10mm 2.8 ED AS NCS CS ultra wide lens.

The optical module for this combination is available but it doesn’t apply to my images because the lens is missing from the EXIF data.

  1. Why is the data missing?
  2. Is there a way to apply the optics module corrections to the images?


Exiftool can add the necessary info. Best check what a file looks like that reports lens data correctly.

It has contacts for aperture but manual zoom only.

I’ll have a crack with ExifToolGUI and see how it goes.

Shame it’s not as easy as clicking and applying optics correction through DXO.

Got Exiftool installed. It won’t let me change the Composite: Lens ID to the correct name that matches with the optical module.

Guess it will be manual lens corrections when I use this lens.

If that lens isn’t written in the exif for it’s manual than in no image that lens will be mentioned. Why is that lens mentioned as a supported lens in PL?


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Composite:Lens ID is, as its name suggests, a composite read-only tag, that is read from various manufacturer-dependent tags.

You need to set the component parts of the lens metadata. Not easy but there are several Google search results on the subject.

Look up ExifTool’s documentation for tags, especially the manufacturer tags ExifTool Tag Names

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I’ve modified a few of my test files a while ago. There are several lens tag fields and it’s not ovious, which field needs to be changed. I have posted it here though and you should be ale to find it with a forum search. If I come across the post later, I’ll add the link

There are absolutely no lens communication contacts on the mount flange so no info goes from the lens to the camera but to see what lens the camera is reporting to EXIF if it is reporting, download EXIFToolGUI and get it set up. Point EXIFToolGUI to the particular image file you want to evaluate you will see four sub windows with tabs. Select the metadata tab then Maker Notes and scroll down the tag name list and look for LensType if your Mk III has written a lens type it will be registered in the Lens Type field. If the camera has not registered any LensType then you will have to write a LensType to Maker Notes then write the LensType to the EXIF LensModel field via the EXIFToolGUI Modify menu.

I have looked through the EXIFtool Pentax Lens Type tags and there is no listing for a Samyang 10mm f/.28 ED AS NCS CS.

Using a manual focus lens you can set the lens focal length for the Shake Reduction to function properly to be able to use the full capability of the Shake Reduction System on the K-3 Mk III check the K-3 Mk III manual page 119 on how to set the focal length so the SR operates properly and also have the focal length reported by the camera to EXIF.

Excuse my ignorance, if DxO lists support for a camera body and lens combo and provides a module for same how is the average user allowed to apply that to their images? Are we saying that we must manually faff about with ExifTool to enable it? If a lens has no contacts to communicate its identity then DxO must know that but seeing that modules are only applied when the software recognises the lens……

I think @George is driving at the same conundrum

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  1. How did that module come in the list?
  2. How are the users expect to use it?


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At least the connection for Nikon F AE seems to have contacts.

For Nikon every D-lens.


The lens is a MANUAL Lens with no electrical contacts, it will NOT show up in the EXIF data as anything other than a manual lens. It has a manual aperture ring and is a manual focus lens. A K-mount Pentax lens has all the contacts. Put that same lens with a Nikon F or D mount on it and being a manual lens it will not report anything to EXIF either. The fricking lens is a MANUAL lens!!! I suspect the lens in question is not the Samyang 10mm F2.8 ED AS NCS CS lens in the optics module.

Samyang only seem to have one listing with multiple mounts (including Pentax K) and no contacts pictured.

So, how can the OP apply the module listed as available by DxO in the first post to their image edits?

He can use EXIFTool to change the maker notes LensType by writing a script that will change the LensType to whatever he wants and then using the EXIFToolGUI modify menu to add the MakerNotes LensType to the EXIF LensModel field. First there must be a valid EXIFTool LensType value for the lens in question, looking through the EXIFTool lens type values there is no such value so the lens was correctly indentified by the camera as an A Series Lens, which means that the lens has a manual aperture ring instead of electronic aperture control.

Looking on line at the Pentax Version of the Samyang 10 mm the rear of the lens is quite a bit different than what is shown above.


I understand that, thank you. Are DxO therefore saying “we’ve produced an optical module for this body/ lens combo but you have to use a tool which (for many) is neither convenient nor necessarily readily understood to activate it. Oh, and we’re not going to provide any information, guidance or instruction how to either”

I think that’s fair. It’s more up to camera and lens manufacturers to provide the means for that, in my opinion, since what we’re talking about is writing EXIF data to a camera RAW file or out-of-camera RGB file. I suggest the OP submit a support ticket at to ask if the optics module in question is indeed the right one and how to apply it.

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I have been watching the posting going on and the discussion has been very insightful.
To clarify, the lens is indeed a Samyang 10mm 2.8 ED AS NCS CS in Pentax K mount.
The lens is manual focus. The aperture can be manually set or set to “A” with aperture control through the camera. There are contacts on the lens but I suspect these are purely for aperture data. It reminds me of the old Pentax SMC-A lenses.

I have installed ExifToolGUI and I’ll have a go at following larrymc’s advice. I’ll also reach out to DXO support as Egregius suggested.
Happy New Year to all.
I’ll post an answer of success or failure.

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You should be able to determine what the camera is reporting the Lens type is. Maker Notes is where Pentax records lens data and that is supposedly where DXO gets their lens data from (shown by my red arrow in the screen capture). I suspect it will show up as LensType A so it is purely a manual lens other than the Camera A setting for aperture control.

BTW the first image posted of the lens was a bit confusing as it had no aperture control lever like all Pentax compatible lens have

Good luck with getting DXO to get this corrected