simple transfer not working

[Steve Zeeeee]

Group,

I back up files on a 2010 mac Pro 10.13.6 High Sierra.

Drag and drop or Super Duper, no matter.

The originals are on 2019 Mac Pro 12.5 Monterrey.

This is what happens to a FEW of the files:

Any thoughts please?

[Lumigraphics]

That's not enough info. Which computer shows that preview image? Are you opening the dng files? Are the originals ok and copies corrupted? What versions of what apps are involved?

[Steve Zeeeee]

the back ups on the 2010 computer are corrupted. 

Originals on the 2019 Mac Pro are ok.  Even when the corrupted files are brought back

to the original computer, 2019 Mac Pro,  they look fine.

I said what versions above.  Corrupted files open fine too.

Seems like the preview file goes wrong.

[Lumigraphics]

No, you didn't explain. Have you actually opened these files on the Mac Pro? If so, what application did you use? How are you creating the dng files?

[Jeff Arola]

How are you moving files from one Mac to the other?

Which Mac is that screenshot from and what version of photoshop?

[Steve Zeeeee]

Mostly move with Super Duper.

Apparently move by drag & drop and Super Duper produces the same corrupt previews.

actually that was a screen shot of a finder preview on the 2010 computer.

[Steve Zeeeee]

hmm, Bridge 2020 sees these corrupt files just fine.

[Kevin Stohlmeyer]

I would not use Super Duper to transfer files.

The other issue you may run into is support for the specific DNG format on such an old OS like High Sierra. It may be corrupting them because it cant read the data coming from Monterey and current PS builds.

[Steve Zeeeee]

I thought that maybe, but it is random so I'm not sure.

[Kevin Stohlmeyer]

Are you physcially connected between the two machines or using a wifi connection?

[Steve Zeeeee]

physically connected, usb

[Conrad_C]

What version of macOS is the 2010 Mac running?

If Bridge and Camera Raw read them just fine, and if the problem is with DNG previews in the Mac Finder, then that is pointing to a possible issue with DNG support in macOS.

Does a DNG display properly in Apple Preview or Apple Photos? Because I think those should use the same macOS DNG code as a Finder preview.

SuperDuper is highly respected and should be OK. I have not used SuperDuper in a while but looking at the screen shots on its web site, I can’t find a checksum or backup validation option, which would help ensure that the backups are exactly identical (not corrupted). If you want to investigate that, you could test backing up using a free trial of other software such as Carbon Copy Cloner or Chronosync. They do have options for backup validation.

But if they were corrupted then they should fail in all applications, and that’s not what’s happening.

[Kevin Stohlmeyer]

OP posted 10.13.6 High Sierra

Was thinking the same thing - it's the OS preview depending if the DNG format is newer than what the OS can preview.

[Jeff Arola]

Does photoshop on the 2010 Mac Pro open the files without corruption?

Are the corrupted looking files all dng?

What camera are the dng files from or were they converted to dng from camera raw files?

[Steve Zeeeee]

Well, Camera Raw opens them without corrption.

All corrupt are DNG files. 

they all are converted to dng from camera raw files.

So it would be nice to be able to see the previews on the back up because that would be the search way.

[Jeff Arola]

What camera are the converted dngs from?

[Steve Zeeeee]

see, this is more of what happens (drag & drop)

Makes it hard to know what is there

[Lumigraphics]

So they aren't corrupted? Just have a bad Finder preview? How did you create these files?

[Steve Zeeeee]

the previews create themselves from raw to dng conversion in LightRoom.

Then transfer to the old mac and previews are corrupt.

[Jeff Arola]

Did you use the adobe dng converter to convert to dng?

What settings did you use in the dng converter?

What camera are the camera raw files from that were convered to dng?

[Steve Zeeeee]

I did use the Adobe dng converter on some files, but most are converted in LightRoom.

The original camera were Nikon D800, D850, nefs

[Steve Zeeeee]

Now the previews are almost all corrupt. 

This is NOT the way to collect archived material.

[Lumigraphics]

I'm guessing its that dng support for the older OS is lagging behind what Adobe is currently doing. There may not be a fix since the dng files themselves are fine.

[Jeff Arola]

Have you tried putting one of the D800/D850 nefs on your Mac Pro High Sierra, then using the dng converter and see if you get the same result?

[Steve Zeeeee]

I'll try but cant right yet.