I've been relentlessly searching the internet, trying to discover if digital zoom could indeed be lossless. I found nothing about it.

So, after thorough testing myself, with a resolution chart, I can confirm that it is—up to 2x!

Please note, this discovery pertains to video ONLY, not still photos. With still images, using digital zoom will inevitably degrade resolution. However, since the sensor's resolution surpasses 4K, we can crop into the sensor while still recording in 4K, maintaining full resolution in the process.

This is partially true.
You will lose some resolution because you only use a smaller portion of the lens, so there is less resolving power.
(assuming the resolving power of the lens is the limiting factor, not the sensor, which was true in the DJI drones I tested with digital zoom)

Montfrooij Posted at 10-20 12:20
This is partially true.
You will lose some resolution because you only use a smaller portion of the lens, so there is less resolving power.
(assuming the resolving power of the lens is the limiting factor, not the sensor, which was true in the DJI drones I tested with digital zoom)

YES, YES, YES!!  Discovered this myself while still testing, and I was confused until I realized the lens itself was the weak link.  

I still use this digital zoom, but cap it at about 1.5 or so.

Thanks for confirming my suspicions.  There is very little information out there about this.

Darrell B. Posted at 10-20 12:29
YES, YES, YES!!  Discovered this myself while still testing, and I was confused until I realized the lens itself was the weak link.  

I still use this digital zoom, but cap it at about 1.5 or so.

True. Very few people know (or seem to care) about the combination of resolution and lens resolving power. And the second one is very hard to measure and depends on a lot of things (so measuring in a lab is not the whole story)
But the end of the story is that you lose resolving power when using a smaller portion of the lens.

I'm surprised by this result. I have the Mini 4 Pro with the latest firmware as of 1/20/2024 and the 2x digital zoom in video is definitely NOT lossless, and it's supposed to use the same sensor as the Mini 3 Pro, correct?

Victor Lin Posted at 1-19 18:17
I'm surprised about this result. I have the Mini 4 Pro with the latest firmware as of 1/20/2024 and the 2x digital zoom in video is definitely NOT lossless, and it's supposed to use the same sensor as the Mini 3 Pro, correct?

This is all wrong. The Mini 3 and Mini 4 have lossy digital zoom. I have both of these drones, the digital zoom on them is the same and unfortunately reduces the resolution. There is no point in using it to record video, it is better to enlarge it in the editor. Makes sense only for observation during flight.

I'm sorry but you either have a very small and bad screen or a very beefy TV that does super sampling on the fly so you don't see the difference.