How to edit a photo as LINKED smart object in PS?

[thomas5CED]

Hello,

LRC already has the option to edit a photo as smart object in PS. If that happens a PSD is generated with a smart object that embedds the original raw file and uses camera raw to develop it. That is already pretty great.

Yet, to my understanding, this copies the raw file to the PSD. That looks unnecessary because the raw file is right next to the PSD in the file system!

Is there an option to create a linked smart object instead of an embedded one when exporting a photo to PS?

[john beardsworth]

No, in LR there is no option to do that - that's a shame - so you have to do something like this:

1. First do a Cmd S (Mac) or Ctrl S (Win) to save edits back to the file, which will help later.
2. Next do an Edit With, opening the file into PS and essentially creating a document of the right size and with any metadata.
3. Save the file at this point (if you don't, there'll be a "can't place file in itself" error in the next step)
4. Then in PS, choose File > Place Linked and add the raw file. It'll probably take you through ACR, which should pick up the adjustments from that Cmd/Ctrl S earlier, and you should check that ACR is outputing a 16 bit file.
5. This should open the file as a linked smart object, centred and filling the document space (if not  make sure the resolution is the same in LR's External Editing prefs and in ACR - so 300 in both cases, or 240 in both). You can now delete the background layer, and you have what you want.

If you now make changes back in LR and do a Cmd/Ctrl S, you'll see the Photoshop link being refreshed.

I am pretty sure that's all the steps.

[Conrad_C]

Also, once you’ve got it set up as a linked Smart Object, that makes it possible to send the edits back to Lightroom Classic. If you edit the linked raw Smart Object in Photoshop by double-clicking to open it in Camera Raw, Camera Raw writes the edits back to the external metadata. Which means, back in Lightroom Classic, you can select that photo and choose Metadata > Read Metadata from File, and that will update the original raw file in Lightroom Classic.

[Laura Emerson]

That's brilliant, thank you very much!

[JohanElzenga]

A faster, but more dangerous, method: Use 'Open as Smart Object' as usual. If you have an embedded smart object in Photoshop, then you can change this to a linked smart object (I type this on my iPad, so I can't check the exact steps). This will export the smart object (i.e. the raw file) to disk. Do this and overwrite the original raw file with the exported raw file. Lightroom won't know that this happened and will see this exported linked raw file as the original raw file.

[richardplondon]

just for background: I've found a smart object always Embeds an internal copy of the placed file. Setting up a link relationship to an external file did not reduce the PS document size, IOW. The external link provides a means of updating the internal copy data to match, if the contents of the external data were to change. Which may well happen for other formats, not for camera Raw - though a different camera exposure could I suppose be substituted by these means.

A PSD / TIF that includes a smart object packaged Raw is not only larger because of that embedded data. PS also requires a full bitmap preview for each smart object LAYER (to cache the results from its particular ACR adjustments, and also from any smart filters or smart transforms that may have been parametrically applied). Then a further full bitmap - a compatibility preview - must be (re)generated during each save, to portray its full layer STACK for the benefit of other applications, such as Lightroom Classic.

Thus, your single photo is being physically represented at least 3 times within this approach.

[JohanElzenga]

Thanks for the info. I tried this a long time ago because I wanted to have a linked object for the reason of being able to update it from Lightroom like Conrad described. I did not check the size of the PSD document because that did not interest me.

[Conrad_C]

just for background: I've found a smart object always Embeds an internal copy of the placed file. Setting up a link relationship to an external file did not reduce the PS document size, IOW.

By @richardplondon

That’s different from what I remember, so I just tested it, and what I got is in the picture below. The test file starts out with a 14 megapixel raw file that’s 18.6MB, dropped into a Photoshop document of the same pixel dimensions as the raw file. In each document, the Photoshop document and the Camera Raw smart object are both set to 16 bits per channel ProPhoto RGB.

In the smart-object-only versions, I deleted the document’s original Background layer because it doesn’t do anything, so the only layer is the raw smart object.

In the versions with layers, the layers are one pixel layer with one healing spot, and one Curves adjustment layer, for a total of three layers including the raw smart object layer.

Two factors affect the file size: Whether there are additional layers, and whether the format is Photoshop, or TIFF with ZIP compression.

In this test, the linked versions are smaller than the embedded versions, and the TIFF+ZIP versions are smaller than the Photoshop format versions. So I like to save them as linked Smart Objects in a Photoshop document saved as TIFF+ZIP. The cost is that TIFF+ZIP can be very slow to save, but at least Photoshop saves in the background so you can keep working. Use Photoshop format if the TIFF+ZIP save time is unacceptable.

[richardplondon]

It was quite some time ago that I made my own trials of smart object linking - perhaps it's different data now, different compressibility, or... my method was bad then. Good news to be able to stand corrected now!

[Laura Emerson]

I just tested this and it works a treat!

I opened my RAW file from LR as a smart object in PS, then right-clicked on the smart object in the Layers panel and chose: "Convert to Linked...", save as dialogue opens, chose the RAW file on my disk, smart object is linked to RAW file on disk. Upon saving the edits done in LR, the smart object updates automatically in PS and vice-versa 

(in LR, go to "Read Metadata from file").

It works very fast and seamlessly. Thank you very much. Big lifesaver!

File size is not really a concern for me. I think it's better than having several versions of the file but am a bit concerned why it may be dangerous to use this method?

[richardplondon]

So far as danger: normal working poses effectively zero danger to the integrity of our Raw files because we are not working ON those; we are only working FROM them. There's no saving changes and suchlike.

But under this procedure e.g. there's nothing ensuring the wrong Raw will not get overwritten by accident.

[Laura Emerson]

Very helpful guys, thank you!

[JohanElzenga]

The danger is that you could overwrite the wrong raw file, or that something goes wrong when you overwrite the raw file that corrupts it. Just make sure you have a backup of your raw files and you should be safe.

[Laura Emerson]

Ah not too bad, as I do have redundant copies. Thanks very much for the info, much appreciated!