What happens to 4k footage on a 1080p timeline?

New to the forum (and Resolve), so apologies if this question has been asked and answered - I did have a search, I promise!

When I drop a 4k clip on a 1080p timeline in Premiere Pro the dimensions of the footage don't change, it simply appears at 100% and is "zoomed in, or cropped if you like" within the timeline viewer. Adjusting the scale from 100% down to 50% then fits the entire clip into frame.

The same doesn't happen in Resolve. If I drop 4k footage on a 1080p timeline (and choose not to change the timeline resolution to match when prompted) it seems to scale the footage to fit the timeline.

So what happens when I adjust the scale of the clip in inspector>transform>zoom? Has the footage been scaled when it was imported onto the timeline, or perhaps nested like in Premiere Pro, in which case I'd be increasing the size of the clip past it's native resolution?

I like knowing exactly where I'm at, I don't like relinquishing control for the sake of convenience. Is there anyway I can have it perform like Premiere Pro and drop the full size clip on the timeline so I can then scale it down to fit (and back up when I want to without interpolating the footage)?

In Premiere I know where the boundaries of scale are before I start scaling the clip past it's native size (interpolating). At 100% it's effectively zoomed in twice the size of a 1080p timeline and I can scale down to 50% before I hit empty space around the edges.. and I know not to push past 100% unless I really have to.

Sorry this question might be a bit verbose, just trying to alleviate any potential ambiguity.

Thanks.

I would suggest reading the relevant section on Image Scaling in the user manual. Try to ignore how Premiere works... it's different.

You can do it either way in Resolve. If you choose the option "scale entire image to fit" under the project Image Scaling preferences (Input Scaling), the system will automatically scale the 4k footage to HD. So you'll see the entire 4K frame at HD resolution.

Or, you can select "Center Crop with no Resizing" which will show you the 4K material at 100%, and you move it around and zoom as you wish.

However, the beauty of the first alternative is that you can zoom/pan/tilt to the full extent of the original 4K resolution without going below the timeline resolution, in this case, HD, as long as you don't exceed the original 4K resolution.

To export 4K, you'd want to change the timeline resolution to 4k before doing so. And in that case, zooming would of course leave you with less than 4K resolution.

John thanks very much for the advice. It's especially nice to know that the first method is utilizing the original 4k resolution when it scales and doesn't up-size the footage that has been down-scaled from 4k to 1080p. That wouldn't be good.

Peter thanks for pointing me to 'image scaling' specifically.