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4K Zoom, more than just digital zoom? [UPDATE]

AnsibleMedia

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So like the rest of us, when I saw the firmware update this morning and read about the zoom feature, I was interested. I was curious to know if DJI had simply implemented a digital zoom, merely cropping in on the existing 4k recording, or if they were making use of the extra resolution available via the quad-bayer sensor of the MA2.

I definitely wanted to test it out. I didn't get to do much, as some major thunderstorms were rolling into my neighborhood after I got out of work, but I was able to do one test before the sky opened up.

I parked the drone in place about 40 feet up, centered on a lightpost. I recorded a short clip in 4K Wide, and a short clip in 4K Zoom, at both 1x and 2x without moving the drone. From each of those clips I took a still frame, cropped in heavily on the lightpost at the center, and scaled the wide and 1x images up to match the 2x field of view. Same lightpost, from the same distance, just different zoom modes. Interestingly enough, the zoom mode makes a surprising difference in the quality. At the same FOV the 1x and 2x are noticeably better than the 4K wide. At least from this brief test it would appear that there is some benefit to this mode vs simply scaling in post.

To be honest, I don't think it would have made much sense for DJI to have included this feature if it weren't receiving the benefit of the 48mp sensor. At least to my eye, the difference between 4K wide and 4k zoom 2x looks pretty similar to the difference between the 12MP and 48MP stills created by the MA2. Not amazingly better, but still better.

Would I use this to create awesome zoomed in cinematic video? Heck no. But it is more than serviceable for more utilitarian purposes such as inspections and so forth, and at least from this one brief initial test better quality than zooming in in post.

Here is an image of the comparison:

Mavic Air 2 4k Comparison.png

You can also download the full size frame grabs here: Your work | Adobe Creative Cloud
And the original raw video clips here: Your work | Adobe Creative Cloud
 
Great input. I can’t wait to test this out myself, been insanely busy. If in fact it does unlock some more hardware potential, or a mix of hardware and digital zoom instead of purely just cropping out and zooming digitally, that would be a game changer. Can’t wait to see some detailed videos about it and try myself.
 
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Interesting results, thanks for testing! I just did a bit of backyard testing myself and my observations are that 4k Wide and 4k Zoom x1 have comparable image qualities with a few subtle differences.

4K Zoom x1 seems to not be so heavily sharpened as the 4K Wide, resulting in a slightly softer, but equally detailed image! This is a nice surprise for all of us who have found the MA2's footage a touch harsh. Also, it seems that there is less visible noise in the picture, which supports my theory that there is less in camera sharpening being applied to 4K Zoom x1.

I can't say such favourable things about 4k Zoom x2 however, as I feel it is significantly softer than the other two, and the noise/grain larger and more visible (especially in the moving footage). That said, overall an excellent little addition to the growing tool kit of the MA2. Happy days!
 
So like the rest of us, when I saw the firmware update this morning and read about the zoom feature, I was interested. I was curious to know if DJI had simply implemented a digital zoom, merely cropping in on the existing 4k recording, or if they were making use of the extra resolution available via the quad-bayer sensor of the MA2.

I definitely wanted to test it out. I didn't get to do much, as some major thunderstorms were rolling into my neighborhood after I got out of work, but I was able to do one test before the sky opened up.

I parked the drone in place about 40 feet up, centered on a lightpost. I recorded a short clip in 4K Wide, and a short clip in 4K Zoom, at both 1x and 2x without moving the drone. From each of those clips I took a still frame, cropped in heavily on the lightpost at the center, and scaled the wide and 1x images up to match the 2x field of view. Same lightpost, from the same distance, just different zoom modes. Interestingly enough, the zoom mode makes a surprising difference in the quality. At the same FOV the 1x and 2x are noticeably better than the 4K wide. At least from this brief test it would appear that there is some benefit to this mode vs simply scaling in post.

To be honest, I don't think it would have made much sense for DJI to have included this feature if it weren't receiving the benefit of the 48mp sensor. At least to my eye, the difference between 4K wide and 4k zoom 2x looks pretty similar to the difference between the 12MP and 48MP stills created by the MA2. Not amazingly better, but still better.

Would I use this to create awesome zoomed in cinematic video? Heck no. But it is more than serviceable for more utilitarian purposes such as inspections and so forth, and at least from this one brief initial test better quality than zooming in in post.

Here is an image of the comparison:

View attachment 110225

You can also download the full size frame grabs here: Your work | Adobe Creative Cloud
And the original raw video clips here: Your work | Adobe Creative Cloud
I was asking myself this question this morng (is there any difference in quality if I just zoom in post) and you thoroughly answered that question...thanks!
 
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I did a little more testing today in a more controlled environment. I was curious to see how the different 4K zoom modes compared to the 12 and 48MP still images.

I set up my drone on a table pointing at a printed lens test sheet under a video light. The drone was 44" away from the test sheet, which is about 5" past the MA2's minimum focusing distance of 1m/39". I took several stills and video clips at ISO 100: 12MP, 48MP, 4K Wide, 4K 1x, 4K 2X.

Again I took single frames from the videos at each zoom level and cropped heavily in on the center, as well as on the JPG stills. Here is a comparison of each at 100% crop to show the relative size of the test sheet at each zoom level:
MA2_100_PERCENT_CROP_COMPARISON.png

Next I scaled each image up until it was the same size/FOV of the 4K 2X. That comparison can be seen here:

MA2_SCALED_FOV_COMPARISON.png

There are of course some differences between JPG compression and the video compression, but to me both the 12mp still and the 4K wide look pretty similar, as do the 48mp still and the 4k 2X.

If I had to guess, I'd say that the 4K Wide mode uses the 12mp mode at nearly the full width of the sensor, and the 4k Zoom is switching over to using it in 48m mode. This is the sensible way for DJI to go about this, as it really wouldn't make much sense to include this as a feature if it weren't making use of the additional resolution of this sensor. If this is the case, then this will be a decent option for some purposes, though you'll be giving up low light performance and some detail in certain scenarios, similar to using the 48mp vs 12mp mode. I've seen a lot of people mocking this feature as being useless and unnecessary, and if this was using a standard sensor I'd tend to agree, but I think people are discounting DJI's ingenuity on this one.

For highest quality video absolutely stick to 4K wide, but if you need to zoom in on something and are working in very good light, I think using these zoom modes is a better alternative than zooming in post. Not to mention it is just plain fun to play with.

DJI has seemed to to a pretty good job implementing this feature, especially since they anticipated that users would want to be able to use the controller to zoom in. If you haven't seen it elsewhere already you can hold down the Fn key on the remote and zoom in and out with the gimbal dial. This will lead to some fun "dolly zoom" like effects I'm sure.
 
Rumor has it the slider effect can be controlled with the wheel by holder down the function button

Yep, I mentioned that at the bottom of my last post. Hold the Fn key and you can use the gimbal dial to smoothly zoom in and out. Tried it today, works much better than dragging the zoom icon on the screen.
 
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Right, don’t criticise the location or the lack of photographic skills, but I had play with the FN + Gimbal wheel zoom control to see if a Dolly Zoom shot was possible:
Very cool! Can't wait to try this out myself.
 
I did a little more testing today in a more controlled environment. I was curious to see how the different 4K zoom modes compared to the 12 and 48MP still images.

I set up my drone on a table pointing at a printed lens test sheet under a video light. The drone was 44" away from the test sheet, which is about 5" past the MA2's minimum focusing distance of 1m/39". I took several stills and video clips at ISO 100: 12MP, 48MP, 4K Wide, 4K 1x, 4K 2X.

Again I took single frames from the videos at each zoom level and cropped heavily in on the center, as well as on the JPG stills. Here is a comparison of each at 100% crop to show the relative size of the test sheet at each zoom level:
<snip>
Appreciate your input, facts and details are sooo much better than opinions regardless of source.
 
If DJI read this post ....... “Many thanks for the free added zoom function on the Mavic Air 2!” Marvellous! Fantastic! Excellent! (That should negate the naysayers for a while ........ ) ????????
 
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