Lightroom Classic plug-in - dates for video not matching

tom_brennan

Using the SmugMug Lightroom Classic Plug-in, it's not clear where the dates for uploaded videos are coming from. The original videos are from a Sony RX100M3, in .MTS format.

The screenshots below show the various date fields in Lightroom, and the final dates in SmugMug, for a sample file. There doesn't appear to be any correlation!

Can anyone advise what field(s) in Lightroom are used to upload dates for video?

Apologies for attaching screenshots - I don't appear to have the ability to embed images? New-ish user?

Jtring

My understanding is that since there are few standards for dates on videos, almost anything goes. Different camera manufactures and different processing programs do different things. I’ve been meaning to sort some of this out for myself sometime, so I took your post as the opportunity to run a few experiments. I'm working with an Olympus E-M5III which puts out a .MOV files (Quicktime) so your results with the .MTS file may vary.

Short answer to your question (at least for my situation): SmugMug's "Date Taken" field lines up with Lightroom's "Date Time Digitized" entry, which, in turn, comes from the "CreateDate" field in my video's Quicktime metadata. That metadata can get messed up in at least two different ways if the original file is processed by Adobe software. In my case, SmugMug's "Date Taken" appears to be time the processed version of the video was written, reported in UTC (Greenwich Time). Adobe made those time reporting choices, not SmugMug.

Read on for details ...

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I shot a short test video using an Olympus E-M5III at just about 3:00 PM local time yesterday. For the .MOV file on the SD Card, Microsoft Windows File Explorer showed the "Date Created" as 3/21/2023 3:00PM and "Date Modified" as 3/21/2023 3:01PM. If use ExifToolGUI, to look at the file on the SD card, I see things like

FileAccessDate and FileCreateDate | 2023:03:21 15:00:54-07:00
FileModifyDate | 2023:03:21 15:01:02-07:00
CreateDate | 2023:02:21 15:00:53
ModifyDate | 2023:02:21 15:00:53

The first three are file system times, but the last two come from the Quicktime metadata. The “-07:00” part is the ISO 8610 standard way as saying that 15:31:03 is 7 hours behind Universal Time. That’s correct: I’m on Pacific Daylight Time now, 7 hours behind Greenwich. Note there is no time zone information for the two Quicktime metatdata fields. That makes sense given my camera does not know the time zone. (Some do, but not Olympus cameras.) Anyway, all looks reasonable so far.

Next, I moved the file onto my hard disk. The two Quicktime metadata date/time fields were unchanged, but some strange things happened to the file date/time values. The Microsoft Windows File Explorer shows the “Date” for the same file, moved to a different place, as 3/21/2023 8:00 AM! It almost looks as if Microsoft used the "CreateDate", saw no “-07:00”, decided the value was UTC, and converted it to my local time. If I look at what the File Explorer has for "Date created" and "Date modified", I do see reasonable values of 3/21/2023 3:02 PM and 3/21/2023 3:01PM, respectively. I repeated the move from SD card to hard drive again later (to a different folder). "Date" was still 8AM, "Date created" was the time I moved the file, and "Date modified" was still 3/21/2023 3:01PM, the value from the metadata "ModifyDate". It is amusing that Microsoft reports a "Date modified" earlier then "Date created".

From this point I tried two branches.

First, I just imported the video into Lightroom Classic and immediately uploaded it to a test gallery using the SmugMug plugin. SmugMug reported both the "Date Taken" and the "Date Modified" as a very nice 2023-03-21 15:00:53. Along the way, Lightroom classic showed

Date Time Original | (blank)
Date Time Digitized | 3/21/2023 3:00:53 PM
Date Time | 3/21/2023 3:12:39 PM

It looks like the SmugMug pulled the "Date Taken" value from Lightroom's "Date Time Digitized" field, which it drew from the original metadata's "CreateDate". That all makes sense. The SmugMug "Date Modified" field may ultimately link back to the metadata "ModifyDate" field. That would make sense too. Lightroom avoided file date/time confusion that Microsoft tried to sow. But do observe Lightroom’s “Date Time” field represents something new: the time I imported the file into Lightroom. At least that didn’t propagate to SmugMug. So on this branch, all looks reasonably tidy.

Second, I loaded my test video into Adobe Photoshop Elements 2021 and made a very simple edit: I saved/exported it at a lower resolution. I then imported that new file into Lightroom Classic and uploaded. SmugMug showed "Date Taken" as 2023-03-21 22:21:00 and "Date Modified" as 2023-02-21 22:21:03 ... both around 10:21 PM. How did that happen?

Coming out of Premier Elements, the new reduced resolution .MP4 file had a file system "Date" of 3/21/2023 3:21 PM. That’s the local time I created that new video file. The time of the source file got lost. It almost must be that way with video editors since one the things those programs can do is to stick pieces from several source files together. If I look at that new file using ExifToolGUI, I see

CreateDate | 2023:03:21 15:21:00-07:00
ModifyDate | 2023:03:21 15:21:03-07:00

All the time zone indicators are there.

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Added Correction late 3/22. The above are from the XMP section of the metadata. The Quicktime section has the UTC equivalents without any time zone indicator: CreateDate | 2023:03:21 22:21:00 and ModifyDate | 2023:03:21 22:21:03. I've also learned since I wrote the above that the Quicktime spec. calls for UTC times. So Premier Elements is just following the spec. And below, Lightroom does not need to convert to UTC. It's already been done here.

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When I load this file into Lightroom Classic, I find

Date Time Original | (blank)
Date Time Digitized | 3/21/2023 10:21:00 PM
Date Time | 3/21/2023 10:21:03 PM

Correction: Just ignore this. Lightroom Classic converted the times to Universal Time. All I can figure is that when the original file did not have the time zone indicator of "-07:00" attached to the Quicktime metadata date/time fields, it assumed UTC ... but when that time zone indicator was there, it converted to UTC. That's a guess, of course, based on one example. I don't have any further insight into Adobe's design intent. Note too that unlike the out-of-camera file, the Lightroom “Date Time” field here comes from the "ModifyDate" field and shows the time Premier Elements created the file, not the time it was imported to Lightroom Classic.

As before, SmugMug's "Date Taken" comes from Lightroom's "Date Time Digitized", which links back to the Quicktime "CreateDate" value. SmugMug's "Date Modified" appears to link back to the Quicktime "ModifyDate". That matches the first, direct upload case. It's just that when processing is involved, the times get shifted to the time the processed file is created, reported in UTC (Greenwich time)! It doesn't look like SmugMug is doing anything more than passing on the weird data inside Lightroom.

I don’t know how this differs from your handling of your .MTS file with whatever processing you choose to do. Perhaps you can use my experiences to guide a few of your own experiments. Report back.

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(Added note: This question has been around before on Dgrin, but never with this much exploration. SmugMug has reported that they use ExifTool to pull metadata out of the files you upload ... same tool I used although I chose the version with a graphical interface.)

(Second added note: My reference to Lightroom Classic's "Date Time Digitized" was drawn from the EXIF selection on the Metadata tab in the Library module. If I use the Default selection, the same value is labelled "Capture Date/Time". Makes sense within the bounds of the odd time handling here.)

Jtring

I've made a few significant edits to my earlier post. All are in italics or cross-outs and should be easy to spot. Still, the same conclusion applies, at least for my .MP4 videos: the time reported in SmugMug is the time the last edited version was created, stated in UTC (Greenwich time). SmugMug reports the actual capture time in the local time zone only if the out-of-camera video is uploaded without any editing.

tom_brennan

Thanks Jim - I haven't had a chance to do any more experiments with my video metadata, but I appreciate the detailed info. I'll report back with any further details.