RSW Posted at 2016-12-19 22:19
Yes it is true. You ignored the whole point about a "given unit of measure" like in a display or a printed images, regardless of the total number of pixels. One inch on the phone screen contains more pixels than on inch on the TV. Wikipedia explains this in some detail with all the caveats but concludes, "The term resolution is often used for a pixel count in digital imaging, even though British, American, Japanese, and international standards specify that it should not be so used, at least in the digital camera field." (https://en.wikipedia.org/wiki/Image_resolution)

On the other hand, the term "total resolution" is often used as the video equivalent of megapixels for a still image. "Total resolution" a bit different than the simple definition of "resolution". It is the width in pixels times the height in pixels and does not take into account any pixels per unit of measure. It's really the total number of pixels is all. When you talk about "total resolution", 4k is indeed 4 times the resolution of 1080. Here are some examples of what I'm talking about.

Resolution has never been defined by total number of pixels. Resolution is always measured in either Pixels per inch or dots per inch....so on a diagonal 40 inch screen 1920x1080 has a resolution of 55 pixels per inch. while 4096x2160 on a 40 inch screen=115 pixels per inch. So while yes it is true that it contains 4 times the amount of total pixels, the pixels per inch is just a little over 2 times....which means that for every inch of HD 1920x1080 you can fit twice as many pixels in the same inch...Which obviously means its able to store twice the amount of information into each inch. Hence the detail in UHD is only twice as much than HD.

raph_london Posted at 2016-3-29 11:06
Hi,
I have tried to record 1080p 120fps ans I was really surprise how bad was the video.
Of course 4K is great but you could have an excellent 1080p feed and here it seems the videos has been filmed in 480p and scaled in 1080p.

When you record video the shutter speed should be set 2 times the frames per second. Which summed up in a nutshell typically if you shoot at 30fps you set it at 60. When recorded at 120fbs that would be 240 for shutter speed. In other words slow mo needs a lot more light than if you were shooting 30fps....Ive noticed the exact same thing on my phone, if I try to record slo mo video on my phone where it wasn't really bright the video just doesn't even record for you..

Here is some footage I took 4K 30 fps - came out nicely - just move the drone smoothly. I reduced to 1080P to see how the low light came out.   Impressive quality! 1080P is great for 120 fps. Play around with them all and its all in the movement. ;)

One point to remember is that 1080p 120 fps uses a croppped mode of the sensor and is not as good as the lower frame rate versions 1080p.

fans7f77f159 Posted at 2017-2-27 16:41
Here is some footage I took 4K 30 fps - came out nicely - just move the drone smoothly. I reduced to 1080P to see how the low light came out.  https://youtu.be/zP2incl-muI Impressive quality! 1080P is great for 120 fps. Play around with them all and its all in the movement. ;)

I would suggest always recording in 4k if you have the means to edit it and re-render if required. That way you're also 'future proofing' your work as much as possible.

DoctorDrone Posted at 2016-3-19 07:56
Drone Man... great question.  I'm no pro either, but I have a little bit of understanding and can offer my 2-cents.  It's complicated to answer because their are many variables to consider when deciding what video size/quality/resolution and fps (frames per second) to shoot at.   To start, we will refer to size/quality/resolution as "size".  Size and fps are 2 separate issues.  The P4 offers the following video modes or settings according to DJI Phantom 4 specs:

UHD: 4096×2160 (4K) 24 / 25p

I am still relatively new to my dji Phantom 4. My problem is that most of the spec'd video modes simply do not exist and the camera does not support them. for example: UHD at 30fps or 1080p@60fps. There is 50 and there is 120, but there is no 60. So did these bits get removed with firmware updates or is there some secret setting I am supposed to enable to get them appear. Because I can live with super choppy 4k at 25fps as long as I get the almost as good UHD at 30, which makes it tolerable and a bit of interpolation can FAKE fluid motion there when you produce some quality content. If I can only get UHD at 25 as well(which seems to be the case) then I have chosen the wrong drone and I would have to return and replace it with the more expensive phantom 4 which claims to make 4k@60fps(the advanced, if memory serves). Can anyone help me out here?

Bonus info: I have PAL(why do we in the digital age still have these analog TV standards complicate our lives?) and 50Hz anti-flicker settings which might contribute to the camera denying me 30 and 60fps modes.... not sure.....

Ubul Posted at 2017-4-22 18:27
I am still relatively new to my dji Phantom 4. My problem is that most of the spec'd video modes simply do not exist and the camera does not support them. for example: UHD at 30fps or 1080p@60fps. There is 50 and there is 120, but there is no 60. So did these bits get removed with firmware updates or is there some secret setting I am supposed to enable to get them appear. Because I can live with super choppy 4k at 25fps as long as I get the almost as good UHD at 30, which makes it tolerable and a bit of interpolation can FAKE fluid motion there when you produce some quality content. If I can only get UHD at 25 as well(which seems to be the case) then I have chosen the wrong drone and I would have to return and replace it with the more expensive phantom 4 which claims to make 4k@60fps(the advanced, if memory serves). Can anyone help me out here?

Bonus info: I have PAL(why do we in the digital age still have these analog TV standards complicate our lives?) and 50Hz anti-flicker settings which might contribute to the camera denying me 30 and 60fps modes.... not sure.....

Change to NTSC mode (I would agree that NTSC and PAL terms should not be used now) and you will see the 30 & 60 fps frame rates appear. The RC, controller & aircraft all need to be connected and powered up for any changes to take effect.

DoctorDrone Posted at 2016-3-19 07:56
Drone Man... great question.  I'm no pro either, but I have a little bit of understanding and can offer my 2-cents.  It's complicated to answer because their are many variables to consider when deciding what video size/quality/resolution and fps (frames per second) to shoot at.   To start, we will refer to size/quality/resolution as "size".  Size and fps are 2 separate issues.  The P4 offers the following video modes or settings according to DJI Phantom 4 specs:

UHD: 4096×2160 (4K) 24 / 25p

hi  great info and explanation - thankyou! Can I ask a question please... I think you'll know the answer..!
I have a MAVIC and as I cant yet view 4K, I switched it to film in HD  - and now know that I inadvertently chose 48fps. I have struggled to edit the footage, as after rendering  (in Prem Pro CS6), the exported footage is both dropping frames OR  including frames that I  have cropped off. Intensely frustrating and meaning I cannot get decent footage; even recropping and re-rendering has no effect - even if I delete the rendered sequences before re-rendering. Do you know of any way that would get me around this - and enable me to get decent and stable footage from the 48fps footage I have? I've tried working with 50fps as it's 'closest' to 48fps amongst other suggestions  - to no avail. Hope you know a way.....!  regards, Mark

DoctorDrone Posted at 2016-3-19 07:56
Drone Man... great question.  I'm no pro either, but I have a little bit of understanding and can offer my 2-cents.  It's complicated to answer because their are many variables to consider when deciding what video size/quality/resolution and fps (frames per second) to shoot at.   To start, we will refer to size/quality/resolution as "size".  Size and fps are 2 separate issues.  The P4 offers the following video modes or settings according to DJI Phantom 4 specs:

UHD: 4096×2160 (4K) 24 / 25p

DoctorDrone fantastic post!  I would only add ( and I think that you mentioned it) that shooting in larger formats allows you to have more room in your video to edit. So if you wanted to use a warp stabilizer for example to really smooth out your footage, shooting it in 4K will give you much more room to correct for the motion you are trying to get rid of. When you export it as 1080 or 1440 to post online or for a deliverable, the crop will get rid of any “edges” that might appear as a result of the stabilizer.

Another thing to consider is how you plan to edit. 4k is a monster to edit smoothly. Shooting in a frame size that is at least one size larger than you plan to finalize the project is usually a good idea. I find that I have to use a proxy workflow to “dumb down” the 4k footage for editing and then ramp it back up to 4k for the final export. That way I can get my cuts and actually see the smoothness of the video I shot while scrolling through it in the editor but the computer only has to handle it for processing at the 720 or 1080 workload.

Both use 100MBPS - so about the same if 4K @ 60p.