How to have photo as locked screen and Apples own wallpaper as home screen?

Unfortunately it is not possible.

The only way to use Apple's Wallpapers on the Home Screen is to select "Set as Wallpaper Pair" - but once a Wallpaper Pair has been created, the Lock Screen Wallpaper cannot be changed. The only way to do it is to find the Apple Wallpaper you want to use on the web, and set it manually as wallpaper on your Home Screen.

You can find more useful information here:

Change the wallpaper on your iPhone - Apple Support

JS-fromDK wrote:

Unfortunately it is not possible.

And yet that's exactly what I have set. A personal photo on the lock screen and Apple wallpaper on the Home screens. Unfortunately, I don't remember how I did it, though I know I didn't find the wallpaper anywhere else.

If you have set your wallpapers before iOS 16, then it was not impossible.

Think I've tried everything. It is not possible to select some of the iOS 16 preinstalled Wallpapers and use them as Home Screen background without setting them as Wallpaper Pair first. Once done, the Lock Screen image cannot be changed. Tried both directly on the lock screen and in Settings → Wallpaper.

Possibly it can be done in the Focus function with Customize Screens?

EDIT: Nobe, that can't be done via Focus either.

JS-fromDK wrote:

If you have set your wallpapers before iOS 16, then it was not impossible.

Perhaps that's what it was then. I can't seem to recreate it so, it's possible it just carried over from iOS 15.

It's almost impossible if it's not like that. Apart from Rainbow Wallpapers, there are no Wallpapers left from iOS 15 - so if your current Home Screen background is not found among the new gallery in iOS 16, then we have found the answer to the mystery.