Pages: [1] 2 3   Go Down

Author Topic: How to run DNG validation  (Read 1201 times)

saiguy

  • Full Member
  • ***
  • Offline Offline
  • Posts: 135
How to run DNG validation
« on: June 23, 2018, 10:29:58 PM »

Can someone tell me how to run DNG validation on folders. I read about it some time ago but can't find where. Jeff Schewe's book, The Digital Negative doesn't cover that. Would like to run it from Adobe Bridge if possible.

thanks,
Logged

digitaldog

  • Sr. Member
  • ****
  • Offline Offline
  • Posts: 13918
    • http://www.digitaldog.net/
Re: How to run DNG validation
« Reply #1 on: June 23, 2018, 10:48:26 PM »

Can be done in Lightroom or with 3rd party software, not aware its possible in Bridge.
Logged
Andrew Rodney
Author “Color Management for Photographers"

Schewe

  • Sr. Member
  • ****
  • Online Online
  • Posts: 6161
    • http:www.schewephoto.com
Re: How to run DNG validation
« Reply #2 on: June 24, 2018, 03:04:33 AM »

Can someone tell me how to run DNG validation on folders. I read about it some time ago but can't find where. Jeff Schewe's book, The Digital Negative doesn't cover that. Would like to run it from Adobe Bridge if possible.


You can do a DNG Validate from either DNG Converter or from ACR/Bridge but the DNG Converter is easiest/quickest. Peter Krogh has written a tutorial available on the ASMP website: dpBestflow.org

You can also use Lightroom and use a command that was added in LR 5 under the Library menu/Validate DNG Files. Peter has written about this as well DNG VERIFICATION IN LIGHTROOM 5
Logged

digitaldog

  • Sr. Member
  • ****
  • Offline Offline
  • Posts: 13918
    • http://www.digitaldog.net/
Re: How to run DNG validation
« Reply #3 on: June 24, 2018, 09:17:59 AM »

How do you do this from ACR Jeff?
I can't get that URL from Peter to open on my end.
Logged
Andrew Rodney
Author “Color Management for Photographers"

saiguy

  • Full Member
  • ***
  • Offline Offline
  • Posts: 135
Re: How to run DNG validation
« Reply #4 on: June 24, 2018, 09:41:39 AM »

Thanks Andrew & Jeff.

My DNG's are SilverFast HDR files on an external drive. They are never in a LR catalog.

Can you tell how to run it from Bridge?
Logged

Schewe

  • Sr. Member
  • ****
  • Online Online
  • Posts: 6161
    • http:www.schewephoto.com
Re: How to run DNG validation
« Reply #5 on: June 24, 2018, 11:20:12 AM »

Thanks Andrew & Jeff.

My DNG's are SilverFast HDR files on an external drive. They are never in a LR catalog.

Can you tell how to run it from Bridge?


You can’t, you need to open the images in ACR and resave as DNG. Or use Dng Converter to reconvert to DNG.
Logged

digitaldog

  • Sr. Member
  • ****
  • Offline Offline
  • Posts: 13918
    • http://www.digitaldog.net/
Re: How to run DNG validation
« Reply #6 on: June 24, 2018, 11:31:52 AM »


You can’t, you need to open the images in ACR and resave as DNG. Or use Dng Converter to reconvert to DNG.
Oh, Lightroom=more better ;D . Re-saving would force every file to be backed up again.
Logged
Andrew Rodney
Author “Color Management for Photographers"

saiguy

  • Full Member
  • ***
  • Offline Offline
  • Posts: 135
Re: How to run DNG validation
« Reply #7 on: June 24, 2018, 01:38:12 PM »

The SilverFast HDR files are saved as .dng  Can't find anything on validation from Bridge help menu.
Logged

FranciscoDisilvestro

  • Sr. Member
  • ****
  • Offline Offline
  • Posts: 1191
    • Frank Disilvestro
Re: How to run DNG validation
« Reply #8 on: June 24, 2018, 04:21:40 PM »

Hi, you cannot use Bridge. The options are:

- ACR - validate the image(s) currently opened in ACR
- Adobe DNG converter - you can check an entire folder by reconverting them to DNG - free
- Lightroom - Perhaps the best option, but you need the licence as in ACR

Now some observations:

The idea behind DNG validation is that a checksum of the original image portion of the file, the one that should never change, is calculated when creating the DNG and stored inside it. What validation does is to recalculate this checksum from the image bits and compare it to the original checksum.

It is important to note that DNGs created outside of the Adobe environment, may not contain this original checksum. This happens with many in-camera generated DNGs.

I do not know if the DNGs created by Silverfast contain this checksum or not. If the DNG does not contain a checksum, LR/ACR will just indicate "not validated". The option here is to regenerate a DNG with any of the Adobe tools.

Oh, Lightroom=more better ;D . Re-saving would force every file to be backed up again.

Yes, LR is the best option, but you need to have the licence. In relation to backup the files again, you can do it to a temporary folder and delete them after the process, so the only requirement is to have enough space on disk.

If starting with "non-verifiable" DNGs as explained previously, you may want to do this backup the first time, as it will not alter the raw image itself.

How do you do this from ACR Jeff?
I can't get that URL from Peter to open on my end.

The URL gives a warning because it it a https link with either an expired or unregistered digital certificate. In most browsers you can override this warning and get to the page. Since you don't have to input  any information in the page, this should not be an issue.

digitaldog

  • Sr. Member
  • ****
  • Offline Offline
  • Posts: 13918
    • http://www.digitaldog.net/
Re: How to run DNG validation
« Reply #9 on: June 24, 2018, 04:28:13 PM »

How do you validate an image open in ACR, gotta rewrite ?
Logged
Andrew Rodney
Author “Color Management for Photographers"

digitaldog

  • Sr. Member
  • ****
  • Offline Offline
  • Posts: 13918
    • http://www.digitaldog.net/
Re: How to run DNG validation
« Reply #10 on: June 24, 2018, 04:33:50 PM »

What I’ve used in the past but now unsupported?
https://basepath.com/new/detail-ImageVerifier.php
Logged
Andrew Rodney
Author “Color Management for Photographers"

saiguy

  • Full Member
  • ***
  • Offline Offline
  • Posts: 135
Re: How to run DNG validation
« Reply #11 on: June 24, 2018, 05:22:26 PM »

Francisco,

Thanks for the detailed info. I have the PS/LR subscription. There is no reason to import the SF8 dng's to LR cat. I develop them with the SilverFast HDR Studio and then they become .tiff files. After passing them thru PS I import them in LR as the masters.

Looks like I should try the Adobe DNG Converter. Will this create new files? I have 4k slide scans so far and 5k more to do for the project I'm doing. Been using .dng for the validation function. Does Adobe DNG Converter act as a stand alone application?

thanks for your input,
Logged

FranciscoDisilvestro

  • Sr. Member
  • ****
  • Offline Offline
  • Posts: 1191
    • Frank Disilvestro
Re: How to run DNG validation
« Reply #12 on: June 24, 2018, 05:25:25 PM »

How do you validate an image open in ACR, gotta rewrite ?

ACR performs the validation when it opens the file. If there is an error it will display a dialogue with the warning. LR does the same when you open an image in the develop module.
This works well for one image at a time. If you want to check multiple images or an entire folder then it is better to use LR (Library -> Validate DNG or use DNG converter as mentioned previously

FranciscoDisilvestro

  • Sr. Member
  • ****
  • Offline Offline
  • Posts: 1191
    • Frank Disilvestro
Re: How to run DNG validation
« Reply #13 on: June 24, 2018, 05:37:57 PM »

Francisco,

Thanks for the detailed info. I have the PS/LR subscription. There is no reason to import the SF8 dng's to LR cat. I develop them with the SilverFast HDR Studio and then they become .tiff files. After passing them thru PS I import them in LR as the masters.

Looks like I should try the Adobe DNG Converter. Will this create new files? I have 4k slide scans so far and 5k more to do for the project I'm doing. Been using .dng for the validation function. Does Adobe DNG Converter act as a stand alone application?

thanks for your input,

Yes, DNG converter creates new files and it runs standalone.

One option that you might consider is to use LR importing with the options “add photos to catalog without moving them” and using minimal previews. In this way you can perform the validation periodically and will use minimal resources/storage.

One final note, the DNG validation is intended to check for data corruption over large periods of time. If you have validation issues just after creating the DNG, then whatever tool you used most certainly has a bug.

saiguy

  • Full Member
  • ***
  • Offline Offline
  • Posts: 135
Re: How to run DNG validation
« Reply #14 on: June 24, 2018, 06:02:14 PM »

Thanks again Francisco.

Will try a separate LRcat for this purpose. Will import one folder first to see if SF does have a checksum viable dng. If not will have to consider the Converter route with duplicated files. Ouch!
Logged

saiguy

  • Full Member
  • ***
  • Offline Offline
  • Posts: 135
Re: How to run DNG validation
« Reply #15 on: June 24, 2018, 06:30:36 PM »

Just created new LRcat. Imported 1 folder [added] of the SF8 dng's. Ran dng validation from Library. Results said Invalid DNG Files 0. Not Validated 117, which was all of them.

So this is confusing and not reliable. So there are no invalid files, yet none are validated.

Will have to consider going thru duplicating 9k files for the validation function via Adobe DNG Converter. The LR masters are tif. Are they not stable files? Then there is always the slides to fall back on.
Logged

FranciscoDisilvestro

  • Sr. Member
  • ****
  • Offline Offline
  • Posts: 1191
    • Frank Disilvestro
Re: How to run DNG validation
« Reply #16 on: June 24, 2018, 06:38:43 PM »

Just created new LRcat. Imported 1 folder [added] of the SF8 dng's. Ran dng validation from Library. Results said Invalid DNG Files 0. Not Validated 117, which was all of them.

So this is confusing and not reliable. So there are no invalid files, yet none are validated.

Will have to consider going thru duplicating 9k files for the validation function via Adobe DNG Converter. The LR masters are tif. Are they not stable files? Then there is always the slides to fall back on.

Hi,

This is just what I mentioned previously. The tool that created the DNGs is not including the checksum. This is normal in most applications / cameras outside the Adobe ecosystem.

If you want the DNG verification functionallity, you need to recreate the DNGs with DNG converter or LR but then you will be able to validate the DNGs from this event towards the future. There is no way to validate from the moment you initially created the DNG. This should not be an issue unless using a tool with a bug.

Data corruption such as "bit rot" may occur over large periods of time, and that is what DNG validation is about

Remember that DNG is just a container, what you include in it is up to the developer of the tool. Most data elements are optional. Not even Adobe includes all possible data. An example: When you convert Nikon NEFs to DNG, the Adobe converter will not include the masked pixels, maybe because Adobe thinks there is no use for them.

digitaldog

  • Sr. Member
  • ****
  • Offline Offline
  • Posts: 13918
    • http://www.digitaldog.net/
Re: How to run DNG validation
« Reply #17 on: June 24, 2018, 07:14:07 PM »

Thanks again Francisco.

Will try a separate LRcat for this purpose. Will import one folder first to see if SF does have a checksum viable dng. If not will have to consider the Converter route with duplicated files. Ouch!
+1, good info worth archiving, didn't know ACR did this upon open even though most of my work takes place in LR.
Logged
Andrew Rodney
Author “Color Management for Photographers"

saiguy

  • Full Member
  • ***
  • Offline Offline
  • Posts: 135
Re: How to run DNG validation
« Reply #18 on: June 24, 2018, 07:30:25 PM »

Francisco,

Just ran the convert to dng function in LR on the above folder. Was fast and was able to validate after. Seems no file duplication is involved.

Thank you for this most useful solution.
Logged

FranciscoDisilvestro

  • Sr. Member
  • ****
  • Offline Offline
  • Posts: 1191
    • Frank Disilvestro
Re: How to run DNG validation
« Reply #19 on: June 24, 2018, 07:47:42 PM »

Francisco,

Just ran the convert to dng function in LR on the above folder. Was fast and was able to validate after. Seems no file duplication is involved.

Thank you for this most useful solution.

Hi,

Make sure it did not created new files, as this is the behaviour I know of LR. Just right click on any image inside LR and select "Show in Explorer" (in windows or equivalent in OSX) and make sure it is the same original folder and not a subfolder or a different one.
Pages: [1] 2 3   Go Up