Photoshop - Ability to set default "Save / Save As" file type to PSB...

The following script can be used to save a previously saved document in the current format, while a new unsaved document will default to PSB, with a standard dialog to select the save location and filename. A keyboard shortcut can be applied to an installed script, possibly replacing the standard save command.

/*
Unsaved Doc Save As to PSB.jsx
v1.0 - 13th August 2024, Stephen Marsh
https://community.adobe.com/t5/photoshop-ecosystem-ideas/photoshop-ability-to-set-default-quot-save-save-as-quot-file-type-to-psb/idc-p/14795865
Info:
- Previously saved files will save using their current format, location and name
- Unsaved files will offer a dialog to save as to PSB, allowing the choice of name and location
*/

#target photoshop

    (function () {

        if (app.documents.length) {

            try {
                app.activeDocument.path;
                executeAction(stringIDToTypeID("save"), undefined, DialogModes.NO);

            } catch (e) {
                var theName = app.activeDocument.name.replace(/\.[^\.]+$/, '');
                var thePath = new Folder("~/Desktop");
                saveAsPSB(new File(thePath + "/" + theName + ".psb"), false, DialogModes.ALL);
            }

        } else {
            alert("You must have a document open to use this script!");
        }

        function saveAsPSB(thePath, asCopy, theDialog) {
            var s2t = function (s) {
                return app.stringIDToTypeID(s);
            };
            var descriptor = new ActionDescriptor();
            var descriptor2 = new ActionDescriptor();
            descriptor.putObject(s2t("as"), s2t("largeDocumentFormat"), descriptor2);
            descriptor.putPath(s2t("in"), thePath);
            descriptor.putBoolean(s2t("copy"), asCopy);
            descriptor.putBoolean(s2t("lowerCase"), true);
            executeAction(s2t("save"), descriptor, theDialog);
        }

    }());

https://prepression.blogspot.com/2017/11/downloading-and-installing-adobe-scripts.html

@Carson Jones 

Yeah, probably correct. I was just focused on native file format. But any existing extension, whatever it is, should carry through and be maintained (as long as the format specs support the file properties).

I'm not sure Photoshop would change the file format of an already existing file that you open. For example, if you open a TIFF file and hit save it preserves the format. The default behaviour would be for newly created documents in PS where it hasn't already been saved in an existing format. As an example I load images as layers out of Bridge using a keyboard shortcut (new to Bridge recently) and then set up and run a script to organize the file for compositing. Where having the option to have PS save in PSB as a default would be useful is for this type of scenario. Currently I always have to change the format to PSB when I save or save as. It's a nuisance and the clicking adds up over years of projects.

I'm generally in favor of this.

There's one practical problem, however: if you reopen an old PSD and just hit Save, you'd suddenly have two files. So somehow it would have to be first save only, not sure how that would work.

What would help tremendously is to have PSB as an option in Lightroom. That would take care of most practical concerns for me.

You have tagged your post with both Mac OS and Windows, but looking at your post history, you seem to using Windows, in which case you can use the keyboard to choose the file format.

When the save dialog appears, press Tab to highlight the Save as type field.

Now press L (for Large document format), and it will change to PSB.

As far as I know, this is not possible on a Mac.

+1 on an action or script.

Installed scripts can have a custom keyboard shortcut applied to them, or an action and F-key shortcut can also be applied.

This is often requested for JPEG. Here is an example screenshot of an action for JPEG where the "modal control" is active, allowing an interactive save so that you can decide on the location and filename. Just record a version for Large Document Format PSB. Scripting allows more possibilities over actions.

This has been brought up before and its not likely to happen. However, you can write a script to save a specific file type and run it via an Action, which can be assigned a shortcut key. This would be the easiest approach to what you want.