What happens to original RAW files when performing focus stacking?

[Generous_observer15A8]

Fairly new to Photoshop and still learning as I go...

When you combine, say, three or five individual photos to do a focus stack, what happens to the original RAW files? Are they "gone" because they were used in the stack, or do the originals remain, so that if you completely screw things up, you can start over?

Similarly, if you do the same thing, only do an exposure stack (Metered, -1EV, +1EV, etc.), what happens to the original RAW files?

Lasly, I had someone show me how to do these stacks in Lr Classic...never tried in PS. Is one preferred over the other?

[Bojan Živković]

Fairly new to Photoshop and still learning as I go...

When you combine, say, three or five individual photos to do a focus stack, what happens to the original RAW files? Are they "gone" because they were used in the stack, or do the originals remain, so that if you completely screw things up, you can start over?

By @Generous_observer15A8

Raw files will remain untouched. If you want to open RAW file it must be converted before opening thus will remain as it is. Also when opening any other format it will be duplicated before loading in Ps, original will remain in its place untouched unless you choose to save over original and overwrite it. If you make mistake there is Undo, Window > History or start entire process from the beginning.

In Lightroom you are not working with original files never, what you see on screen is possible outcome if you decide to export file. When exporting original file will be duplicated, settings applied then exported, original file is never changed anyway, in whatever format.

[Generous_observer15A8]

Thank you for the insightful and educational reply! 

[D Fosse]

It's a new file. Nothing ever happens to original raw files, they cannot be overwritten. You can always go back.

You have a little more control over the stacking/merging in Photoshop - but  doing it in Lightroom produces a genuine raw file with the full dynamic range and editing headroom. Things like full highlight recovery can't be done on an RGB file in Photoshop.

In other words, the difference is whether you do the basic processing before or after.

[Generous_observer15A8]

Thank you for your knowledge and expertise!

[Conrad_C]

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@Generous_observer15A8 wrote:

what happens to the original RAW files? …the originals remain, so that if you completely screw things up, you can start over?

Whether raw or not raw, the result is the same: To stack files, they have to be combined by copying the files into a new Photoshop document as separate layers, and what happens in that new Photoshop document doesn’t affect the originals, whatever format the originals were.

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@Generous_observer15A8 wrote:

When you combine, say, three or five individual photos to do a focus stack…Lasly, I had someone show me how to do these stacks in Lr Classic...

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Lightroom Classic cannot do focus stacking. It can merge multiple photos into an HDR image, or it can merge multiple photos into a panorama, but it cannot currently merge multiple photos into a focus stack.

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@Generous_observer15A8 wrote:

Lasly, I had someone show me how to do these stacks in Lr Classic...never tried in PS. Is one preferred over the other?

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You can actually do HDR and panorama merging in Lightroom Classic, Adobe Camera Raw, and Photoshop. Additionally, in Photoshop alone you can do focus stacking and more kinds of stack operations (such as noise reduction, multiple exposure alignment, and “tourist removal”). 

An important difference is the file type you get. The merge features in Lightroom Classic and Adobe Camera Raw produce a DNG file, which attempts to keep the result as close to raw as it can. The merge features in Photoshop produce a Photoshop document with layers. Both ways have different advantages.

For a given merge feature, the options and algorithms are not the same across those applications. For example, you get a different set of options if you merge to HDR or panorama in Lightroom Classic than you do in Photoshop. This is actually a good thing, because if the merge fails or looks bad in one application, you might get a better result in the other.

[Generous_observer15A8]

Thaks so much for your in-depth reply...appreciate your time and expertise!