Lightroom SDK: support sub-second capture time in raw metadata.

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  • Updated 4 years ago
Presently, there is no way to obtain sub-second date-time information in Lightroom.

One can resort to exif-tool, but it's considerably less convenient than if the information were obtainable via sdk function.

Two use cases at the moment:
- Filenaming based on capture-time that is unique without additional info to distinguish same second captures.
- Auto-stacking bursts based on capture time.
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Rob Cole

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Posted 7 years ago

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John R. Ellis, Champion

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If subsecond time is available in the metadata, doesn't the SDK return the date/time as a floating point number, with the fractional part non-zero? I have a vagure memory that it did, but I could be hallucinating.
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Rob Cole

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I certainly didn't think so when I typed this up. But, I've made mistakes before...

History:
I recently came up with a new filenaming scheme such that alphabetical order is the same as capture time order. This Idea was issued when I ran into the problem with the subsec field I was hoping to use.

Note: It takes a different exif-tool command to get date-time-original with subseconds than without, and not all cameras support subsecond metadata.

Because of the latter I'm less gung-ho about this Idea, and it may be the reason Adobe didn't support it in the first place...
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Bryn Forbes

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Having sub second data might help the auto stack by capture time which doesn't work well at all. I use a high frame rate camera to shoot bracketed panoramas. So I can shoot SET1: 0,-2,+2 and start SET2 before the second is up and I'm not patient enough to sit and wait for a full second gap between the bracketed sets
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Steve Sprengel, Champion

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For cameras without sub-second times, the shutter-count or image-sequence or something else that is sequential that keeps filenames from clashing on the card, could be used as a proxy for subsecond times to keep images taken within the same second from having exactly the same timestamp metadata.

About the only problem I can see with this is detecting when the image-sequence has wrapped from 9999 to 0000 and not think the 0000 image is before the 9999 image.
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Rob Cole

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Hmm - I'm using (in some of my plugins) a same-second sequence number to assure intra-second uniqueness (when subsec not in exif), but shutter count is an interesting idea, since it doesn't have the potential rollover problem. Of course you still have to cope if no shutter count in exif..

Worth noting: image number can't rollover in the same folder, or it would be a duplicate filename on the card itself, so using folder name/number is another way to resolve.
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Steve Sprengel, Champion

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Of course using the folder and original filename means that the photos have to be imported into LR from the card and/or using the native filenames, instead of an Add Import from some arbitrarily-named files on the hard-disk.
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Rob Cole

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I think we've established that a robust handling requires a plan A, and at least a plan B, if not a plan C.

i.e.
plan A: use subsec if available.
plan B: I just emulate with same-sec uniqueness number, and no plan C. But if you use shutter speed or some such thing which is more robust when present, then you need a plan C when not present.

You're preachin' to the choir Steve - I know, and understand already.......

To be more specific: if folder number is one of your plans, and it's not available, then you need another fallback plan - agreed...

To be more clear: I was considering folder number from exif, ditto for image number, which is independent of file name and location on disk.