Newbie "stupid" question about screen size

[Mr.Burns.666]

Hi Guys
Am pretty new to "the drone world" and i would like to have your opinion on something...
I've notice that when i play back a video on a small screen...i got no lag at all , when
i play the same video on a little bigger screen,i' start to notice some minor lag and when
i play the same video again but on a big screen,i got quite some lag...
I know it's normal,the "video card" have to "work harder" when the resolution is higher...
My question: Does this "law" also apply to the size of the screen you are using to fly your drone ??
Meaning that would you get more lag in the video signal using the biggest iPad available versus
the smallest ipad available ??
Thanks !!

 

[Ansia]

Hi Guys
Am pretty new to "the drone world" and i would like to have your opinion on something...
I've notice that when i play back a video on a small screen...i got no lag at all , when
i play the same video on a little bigger screen,i' start to notice some minor lag and when
i play the same video again but on a big screen,i got quite some lag...
I know it's normal,the "video card" have to "work harder" when the resolution is higher...
My question: Does this "law" also apply to the size of the screen you are using to fly your drone ??
Meaning that would you get more lag in the video signal using the biggest iPad available versus
the smallest ipad available ??
Thanks !!

Screen size does not equal to resolution. A 32" screen running at 1080p has the same resolution as a 65" screen at 1080p. Bigger iPads usually have more processing power than the smaller ones, therefore you are more likely to encounter lag on an iPad Mini than on an iPad Pro.

You will have to give us more information where are you experiemcing this lag.

 

[Mr.Burns.666]

Hi Ansia and thanks for the fast answer !!
Well...let me give you another exemple.
So far,i've had 3 Phantom drone in the last month,from a Phantom 3 to a
Phantom 3 Pro to a brand new Phantom 4 Pro.
I've use a iPad Pro 10.5" with all those birds.
So my iPad Pro is my only "reference".
A week ago i've bought a used pair of DJI Google Racing.
The DJI Google offer 3 "fly mode view".
The lowest resolution give the least amount of lag in the video signal
And of course the highest resolution (1080P) give the most amount of lag.
The difference is not that big but it's harder to be precise when there is lag in the video signal
I did some more research and what matter is suppose to be the ppi number (pixel per inch).
Since i didn't like the DJI Google enough am gonna sell them and my plan was to upgrade my iPad
for the biggest one but i was scare that this would potentially cause more lag than with my 10.5"
It turn out that they have the same ppi number so nothing should change...
Thanks Again for your help Ansia

 

[Ansia]

I don't know if you are aware but Phantoms run in Lightbridge signal (except for your P3S) which are suseptible to magnetic and wifi interference. Also, the higher the resolution, the greater the bandwith it requires, so the farther you go, plus the interference from the world, will cause some kind of delay. This is the reason I run my stream at 720p. To make sure the delay is kept at a minimum. I use various devices for flight. An iphone 6, iphone 6s. Samsung galaxy 8, ipad mini 4, and samsung galaxy tab s4. They are all set to the same preferences and I have only experienced delay on the ipad mini when I was flying on a really hot day and the processor throttled to prevent overheating.

 

[Mr.Burns.666]

Yes,i am aware of the lightbridge signal and there are a good amount of magnetic interference where i mostly fly so am kinda "start with two strike".
Again,another newbie question...where do you adjust your stream down to 720P? In the DJI Go 4 app or in your ipad/iphone setting ?
I don't remember seeing this anywhere...

 

[Capt KO]

Even if you were filming in 1080P to your SD card, your video to your device is going to be 720P automatically. So if you want to record your screen, it’s going to be 720.

 

[Mr.Burns.666]

I never record the screen,always only use the microsd card from the drone for recording.
From Ansia last post,i thought there was a way to lower the video signal resolution in order to have a even better video transmission but with a lower overall quality.

 

[Capt KO]

No matter what resolution you record in, your device is going to receive video at 720P. Using my big iPad or my mini4 or DJI goggles, I have NO lag. P3S, 2 P4S, and P4P with standard and + RC’s for the P4’s. Still no lag on my devices. I know this doesn’t answer your problem, but at least you know there are others that do not have it. So it sounds solvable. Best of luck. Have fun fly safe.

 

[Mr.Burns.666]

Hi Capt KO and thanks for your reply!
Well that answer the "receive video resolution question"...
I've probably misuse the word "lag" in my video signal transmission question...
I probably should have use the word "latency" instead.
Like in my DJI Google Racing,i can notice a difference in latency (delay of reaction) between the 3 view mode.( i don't get any lag )
When am using the highest resolution of the Googles which is 1080P,my flying ability is compromise a little because
the bird is not "reacting in real time" enough compare to the low resolution mode,am much more confident because i don't
feel that latency even if there is still a latency...it can't be avoid but am looking to keep that latency to the very minimum.
I've also try to use the DJI Googles as "viewing device" only,i was flying the bird using my iPad and using the HDMI output
of the controller to feed the Googles,it was unusable...the latency was way too high to do anything...

 

[Ansia]

Oh. I forgot to say. I fly a P4P v2, which does output at 1080p. I forgot that lightbride birds output at 720p. You can lower it down to 480p as well.

 

[Mr.Burns.666]

How to lower it down to 480P ?

 

[Ansia]

I tried to do it on the Go 4 app but the option that lets me do it is missing. When I get home in about 8 hours I will connect my bird and show you.

 

[Mr.Burns.666]

Okay...great !!
Thanks Ansia !

 

[Capt KO]

Oh. I forgot to say. I fly a P4P v2, which does output at 1080p. I forgot that lightbride birds output at 720p. You can lower it down to 480p as well.

Thanks for the update on the model you fly. I do not have ocusync, but wish I did. I will soon, so I will sit back and learn. Take care.

 

[Ansia]

Thanks for the update on the model you fly. I do not have ocusync, but wish I did. I will soon, so I will sit back and learn. Take care.

I will tell you one thing. Once you fly with Ocusync, it will be hard to go back to Lightbridge. It's just THAT good. The ability to change channels when interference is detected, and ever since we got the update to Ocusync 2.0 and it changes between 2.4Ghz and 5.8Ghz and between all the channels in those bands, it really takes a lot of effort to get interference on my screen.

 

[Oso]

where do you adjust your stream down to 720P? In the DJI Go 4 app or in your ipad/iphone setting ?
I don't remember seeing this anywhere...

You mentioned you had a few different Phantoms. For your P3P at least, the downlink video bitrate is adjusted in the app in the image transmission settings but only when it is set to custom. The setting (a slider) is not there when set to auto. People sometimes adjust the downlink bitrate lower to help poorer spec’d mobile devices process smoother and/or lower latency video or to help maintain a video downlink over greater distances.

Some countries do not permit switching to custom, so people in those countries sometimes choose to set their mobile device to countries which do allow it.

 

[Bug Shredder]

First off all you should never do a playback from the SD card. Download the video onto your hard drive then play it back. It will be much smoother and flicker free. And, too, playing back video from the card will often corrupt the file.

 

[Ansia]

First off all you should never do a playback from the SD card. Download the video onto your hard drive then play it back. It will be much smoother and flicker free. And, too, playing back video from the card will often corrupt the file.

We are talking about the video feed you get in your device. Not the video recorded in the SD card.

 

[KachemakDiver]

When I experienced real time lag and pixel issues on an iPad, was when I had way to many apps running in the background. The fix for me was to get a more powerful mobile device and disable everything that I didn’t need to fly the phantom. The iPad mini 2 that I was using would do the job well until I added other apps that I needed for other stuff. Now I use a Samsung tabE that I had bought new but never used. I found an old post on this forum that gave me step-by-step instructions on how to set it up for being a dedicated device for my phantoms. Never had any issues since!
Might be worth checking out for you.

 

[Ansia]

Here is the guide @KachemakDiver is talking about.

Install DJI GO on an Android Tablet or Phone (Step-by-Step Guide) | Phantom Help

Phantom Help is a site for help with DJI Phantom drones. Find the latest fixes, how-tos, guides, accessories, modifications, and more.

www.phantomhelp.com