Using Auto Levels on a Smart Object

[Vernal Bogneris]

I recently noticed I can apply Auto Tone to Smart Objects, but I don't see any way to edit or retract the effect after it's applied. This seems odd for an otherwise non-destructively editable smart object. I feel like I'm missing something. Thanks for any helpful info!

[Myra Ferguson]

Not all operations you perform on Smart Objects are non-destructive. There's a list of the ones that are non-destructive here:

• Work with Smart Objects - Smart Object benefits

[Jeff Arola]

If you go to Image>Adjustments>Levels, that seems to reset or undo any of the Image>Auto Tone, Contast or Color adjustments.

[Vernal Bogneris]

That is good to know, thank you!

[barbara_a]

You can apply the Auto Tone non-destructively by creating a Levels or Curves adjustment layer. Click the “Auto” button . to change options, Alt or Option click the “Auto” button.

[Vernal Bogneris · Accepted solution]

Thank you. It can also be done by applying a Levels smart filter.

I initially found the effects were very different: applying Auto Tone, versus clicking Auto within the Levels dialog box. After experimenting, it seems I can choose (in the Levels dialog box) the Auto Options... and select "Enhance Per Channel Contrast" to more closely match the Auto Tone effect.

I find Auto Tone a good starting point but find it often goes to far, so this will allow me to apply it and then made tweaks to what it has done to the Levels settings, or (when doing it via an Adjustment Layer) backing it off by reducing the layer opacity to the right blend.

Thanks for the help, I've found what works for me!

[c.pfaffenbichler]

The effect also seems to be hosed on simply updating the Smart Object (performing any History-relevant operation that has no effect on the appearance of the image and saving it).