does Lightroom corrupt DNGs or PSU display them incorrectly?

[fbungarz]

Dear Hert,
adjusting DNGs in Lightroom and updating the previews leads to weird results in IDImager. Unfortunately the situation is no better in PSU either.
Here is what happens:
(1) IDImager:
Updating thumbnails via F8 displays the image according to the adjustments made, but full-size view with RAW loading enabled displays weird stripes, here two screen shots:
Thumbnail after adjustments

IDI-ThumbUpdating.jpg (58.19 KiB) Viewed 8063 times

Weird Full Size View

IDI_weirdFullView.jpg (46.14 KiB) Viewed 8063 times

(2) PSU:
Not really sure if thumbnails do update after the DNG has been adjusted in Lightroom as F8 does nothing. BUt what is definitely strange: Loading the image via preview or light table loads the full size DNG, not the preview. Selecting "load full size images" then does the opposite, it exchanges the full size image for its preview. Again screenshots:
In Preview the full size image gets loaded:

PSU_FullSizeDNG_loads_as_Preview.jpg (45.8 KiB) Viewed 8063 times

Changing to Full Size loads the Preview (Perhaps not visible at this magnification, but this one is more pixelated):

PSU_Preview_loads_as_FullSize.jpg (47.94 KiB) Viewed 8063 times

Now, I do not know what actually goes on here. In Windows Explorer thumbnails are no longer displayed after the lightroom edits, the images still can be opened via photoshop or FastPictureViewer, but no longer with Windows Standard Image Viewer. So perjaps Lightroom is to blame? But with gzilllions of lightroom users? I kind of doubt it...

Thanks for looking into it.

Cheers,
Frank

[fbungarz]

OK, for those who are interested, I figured out what is wrong:
In Lightroom 4 you have the option to select to save DNGs as "fast view", which means they load faster in Lightroom, but otherwise all other software sees the images as corrupted. Adobe has NOT documented this new "fast view" standard DESPITE claiming DNG is now supposedly "open source" and not "proprietary". Windows default image viewer shows the files as corrupt after the preview update with "fast view" enabled.
Took me a bit of "sleuthing".
So, good news: neither IDI nor PSU are to blame...
And for interoperability I definitely recommend turning "fast view" in Lightroom OFF.
Cheers,
Frank

[Hert]

Great find Frank. And thank you for sharing.
Hert

[weidmic]

I have reported this problem a long time ago already...
Not a big deal, but if this can be resolved at some point that would be neat.

Michael

[Hert]

I have reported this problem a long time ago already...
Not a big deal, but if this can be resolved at some point that would be neat.

I assume you mean you reported this to Adobe, a long time ago?

Frank mentions that "fast view" is an undocumented (proprietary) way of writing image data to the DNG file. To me that indicates that "fast view" changes DNG from being an OPEN format to a CLOSED format and I support Frank's recommendation that if interoperability is important for you that you should never use "fast view".

[DirkS]

In Lightroom 4 you have the option to select to save DNGs as "fast view",

I have not seen any corruption so far, but I'd like to avoid it.
Where can I find this setting? Is it 'embed fast load data'?

Gr.
Dirk.

[weidmic]

Dirk,

Where can I find this setting? Is it 'embed fast load data'?

Yes, exactly...

Michael

[fbungarz]

Hi Dirk,
yes, that is the one...
You likely do not notice it if you do not use Window's standard viewer or IDI. In PSU photos "seem" to load correctly, but actually preview and full view are mixed up.
Frank

[weidmic]

Dirk,
Now that is funny...
I tried this setting again but it seems no longer to be an issue.

Maybe Frank needs to update the DNG converter? ***

Dirk, can you verify that this setting is working fine at your computer?

Regards,
Michael

Edit: *** or maybe it's because of the chosen compatibility?
I used camera raw 7.1 and higher...

[DirkS]

I have only used LR for the Iast couple of weeks. I still use DNG converter (in PSu) to convert to DNG.
So far I have not seen any problems in PSu and other software (checked in irfanview), but I have not done a lot of editing in LR; I'm still working on getting everything set up properly.

I have to get back to you about my metadata / preview settings in LR. I *think* my settings were also the latest Camera Raw version (7.1) and fast load enabled.

Gr.
Dirk.

[WIanB]

I use Lightroom 4.4 and always use the following settings when converting to DNG 'Use ACR 7.1 or later' & 'Embed fast load data'. No problems with viewing these DNG's in PSu.