Legend

Question

Question: DNG checksum creation.

Forum|Forum|4 years ago
March 7, 2022
2 replies
672 views

Hi, I have a small question.

Is creation of the checksum within DNG possible for all DNGs?

To clarify by choosing the option "Update Preview and Metadata" I was indeed able to create within "Sigma DNG" the checksum for the validation.

I cannot yet test other brands that use DNG (Leica, Hasselblad, Pentax, Fujifilm, etc...) so I would like to have confirmation that the option would work with those DNG as well.

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This topic has been closed for replies.

C.CellaAuthor

Legend

@TheDigitalDog

I used "Update DNG Preview & Metadata for all the DNGs I have.

I get this now:

I am quite confused.

@Rikk Flohr: Photography

Can you or anyone else at Adobe clarify this,

Does the "Update DNG Preview & Metadata" create a checksum also for DNGs by camera manufacturers or not?

If after using "Update DNG Preview & Metadata" a checksum is not created then why performing a "Validate DNG" confirms that the existing DNG are valid!?

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TheDigitalDog

Inspiring

It's all been explained:

https://helpx.adobe.com/lightroom-classic/help/metadata-basics-actions.html

If you’re working with a DNG file, choose Metadata > Update DNG Previews & Metadata to save metadata changes to the file and also generate a preview based on the current raw processing settings.

Author “Color Management for Photographers" & "Photoshop CC Color Management/pluralsight"

C.CellaAuthor

Legend

How do you explain the DNG Validation then?

If no checksum is created after "Update DNG Preview and Metadata" then why Lr says they are finally validated?

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TheDigitalDog

Inspiring

https://www.dpbestflow.org/data-validation/dng-validation#adobe

https://jkost.com/blog/2013/08/dng-verification-in-lightroom-5.html

Note: Only DNG files created by Adobe software can be validated (camera-‐created DNGs cannot be validated because they do not contain the necessary checksum).

Author “Color Management for Photographers" & "Photoshop CC Color Management/pluralsight"

C.CellaAuthor

Legend

@TheDigitalDog

So I did the test again.

Imported 2 Sigma DNG, no Metadata added on import.

Then Library > Validate DNG

I get this message:

Then I used the option "Update DNG preview & Metadata" only on one of the two DNG.

Then again Library > Validate DNG

I get this now.

So I as i said in my OP I believe that one DNG now has the checksum while the other hasn't.

TheDigitalDog

Inspiring

Again: Only DNG files created by Adobe software can be validated (camera-‐created DNGs cannot be validated because they do not contain the necessary checksum).

Update metadata DNG isn't the same as converting to DNG using an Adobe conversion. You can try that. Or, again, it may be that camera DNGs can't be validated at all.

Author “Color Management for Photographers" & "Photoshop CC Color Management/pluralsight"

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