P: Lens Corrections defaults not correct if Previews are "Embedded & Sidecar"

Distorted DJI Osmo Mobile 2 imports (solved)
Hey All,
I found and solved and issue with photos imported to Lightroom mobile from the DJI app for iOS.
Ensure you deselect the "Lens Profile Corrections" for importing photos in the setting.

When "Lens Profile Corrections" is on -it will warp the your photo to an unusable state. 

After the photo has been imported you can apply the lens correction if needed, Just don't do it at import! It will remain distorted if then imported to Lightroom Classic from Lightroom CC. 

Looks to be a bug with the camera profile metadata saved to the image within the DJI app.

No I did not. I just tried importing 25 Canon PowerShot G9 X MKII 20 Megapixel raw files from a new shooting session. These have never been imported into LR and the time with Build Standard Previews was 1.2 sec. with 'Generate Previews in Parallel' (same as before). The 5D MKII raw files are 21 Megapixel so only 5% larger. You are correct that the Camera Raw cache building increases the import time (~.7 sec. and 1.2 sec.). But it's ~40% faster than the previous import time of 2.0 sec. so a definite improvement.

Todd, when you timed import with various settings, did you purge the ACR cache (Preferences > Performance Purge Cache) before each run?  I'm doing some timing and observed that standard previews build about as fast as embedded previews when you re-import the photos but go about twice as slow on an empty cache (I think I remember a comment by Chris Cox or Simon Chen a long time ago to this effect).

Will do–Thanks Rikk!

Thanks Todd, for the videos. Please leave them posted for the team to review. I was able to reproduce and have logged a bug for this. 

"It seems to me that importing with standard previews is now much faster than it used to be"

Agreed. It used to take ~2.0 sec to build a Standard Preview with my Canon 5D MKII 21 Megapixel raw files. Using LR 7.5 it takes <0.7 sec. with the same 2560 px Medium Preview settings. If Adobe did something to speed-up Standard Preview building that slows down Embedded & Sidecar I'd call that a bug. I didn't run a benchmark previously using Embedded & Sidecar Previews so it's hard to say for sure something has changed, but It seems slower. If it's not much faster than using Standard Import Previews the only benefit is if you need to do extensive 1:1 Zoom review before editing. I don't think that was Adobe's intention so it looks like a bug may have been introduced.

It seems to me that importing with standard previews is now much faster than it used to be, so if that is a bug, then I would like to see a lot more bugs like that! 🙂

"Until recently, Lightroom would first generate all the standard previews, and then as the last step they would appear in the collection. That made import very slow, and 'Embedded & Sidecar' made it much faster. Now the sequence seems to have changed."

I remember the same behavior when first using Embedded & Sidecar Preview workflow with LR Classic 7.0 back in October 2017. I didn't run any tests to compare it against Standard Import Previews because it was clearly much faster. It would still be useful if you have to review a shoot at 1:1 Zoom view before editing since building 1:1 Import Previews will take much longer. Begs the question as to what changed and is it a bug?

Interesting observation. It seems that something has changed in the import sequence recently, probably in LR 7.5 in fact. I always add the imported photos to a collection, and use the moment they appear in that collection as the moment of 'being imported'. Because stacks are local, I want to work with them from within that collection.

Until recently, Lightroom would first generate all the standard previews, and then as the last step they would appear in the collection. That made import very slow, and 'Embedded & Sidecar' made it much faster. Now the sequence seems to have changed. I see the images appear in the collection and then the previews are being updated. That makes the difference between Standard and Embedded indeed much smaller. I timed it for 30 Sony A7R III images and see the same difference of 'Embedded' now only about 10% faster.

Good to know, thanks. That makes Embedded & Sidecar a lot less useful (pretty much useless in fact).

I've seen this 'bug' for years and that's why I never use LRs lens profiles.  I open images I wish to post-process in DxO (from within LR as an external editor), apply the DxO profiles—which are far superior IMHO—to the raw files, and close DxO.  The resultant raw files goes back into LR with an attached .dop file and the lens corrections remain in place.

Sometimes one needs a specialist application like DxO to do what a generalist application like Lightroom can't hope to accomplish.  (I have also found that DxO updates their lens/camera combinations far more often than does Adobe.)