When is 120fps NOT 120fps? // DJI O3 Air Unit 4k120 latency and refresh rate testing

[@BaconNinjaFPV]

Thank you for confirming this!! I recently did these tests on the v2 goggles, but suspected this to be the case with the goggles 2 at 120fps since we have heard from the start that the panels are 100hz max. It made the most sense that they would be sending 60fps over the video link, but recording at 120fps on board.

[@ChrisRosser]

Yep. That's what's happening, just don't want Goggles 2 users to switch to 120fps and suffer worse latency!

[@torpedoLaw]

You both get bacon for this!!

[@BaconNinjaFPV]

@@torpedoLaw I will take mine crispy, as always. lol

[@oneeyefpv]

The joy in his face when he says the LEDs turn on "exactly at the same moment" :-)

[@ChrisRosser]

It's kind of cool to know they light up within a few billionths of a second of each other. Few things are that fast!

[@abertheham]

@@ChrisRosser It is so cool when you think about it though. So cool. Excellent work, Chris - thank you so much!

[@jmillerfpv]

@@ChrisRosserShould have used 2 cheetahs 🐆 🐆 . Faster than leds

[@CantFly_FPV]

@@ChrisRosser Thank you! I tried to tell that to my ex but she just kept calling me premature... jokes on her though cus the word is immature!

[@andykirby]

Nicely explained Chris 👌🏼

[@DroneDocs]

Thank you! We were all very curious about this.

[@ChrisRosser]

Glad it was helpful!

[@PIDtoolbox]

Excellent test results Chris! Thanks!

[@MCsCreations]

Fascinating results indeed, Chris! Thanks for testing it! 😃 Stay safe there with your family! 🖖😊

[@JZEFPV]

I was wondering exactly this. I’m glad you did this testing and made this video. Thanks!

[@jessjess3369]

Huge respect for you sir! Thanks for the explanation

[@marcocristalli]

Thanks Chris! What’s the behavior of the Goggles 2 with the OG Air Unit and Vistas (in terms of latency)? Have you tested it?

[@Juan_Reyes_308]

Thank you @baconNinjaFPV and @ChrisRosser, I learned something informative today... 😊

[@ChrisRosser]

Glad to help!

[@haks_123]

Why isn’t anyone talking about this?!, this needs to be shared around immediately.

[@droneguynh6371]

Mind blown! I'm pretty intelligent, but I love how you made this as simple as possible. I love science!

[@enrico320i]

Can Confirm that 100% for Goggles 2, was flying yesterday with the New Update on Goggles 2 and O3 Air Unit. Was flying before 2,7k 4:3 100fps, tested 2,7k 4:3 120fps and it immediately feels like switching to 60fps mode. So in the End like in your test 100fps feels best for flying with lowest Latency.👌 on Goggles 2.

[@PMB15]

Great work, really helpful

[@dkieng]

Thank you so much for the video.

[@gmivisualsjason3729]

Excellent information

[@MysteryD]

Thanks for the clear explanation of your testing methods on latency.

[@ChrisRosser]

My pleasure! You were spot on that a quick explanation was needed 🤠

[@MysteryD]

@@ChrisRosser You couldn't have made it easier to understand (not that I ever didn't... I just worry that the layman sees rolling frames and gets confused)

[@jas-FPV]

Thx, finally someone testing and not just reading some specs and making bogus conclusions Hah, I was right, that they use half framerate in the goggles 2😊

[@alexjx1]

Thank you very much for this. I'm new to digital system. And this is a very instesting finding... I thought the recording fps and resolution has nothing to do with what we see in the video link.

[@ChrisRosser]

Resolution/fov has no effect. FPS has a big effect.

[@adrenalinefilmspr]

Great info.

[@GianmariaVeronese]

Hi Chris, since the latest firmware released 4K/30fps, can you please also test 30fps VS 60fps? For filming purposes I prefer to use 30fps in combination with 1/60" shutter speed, but I'm wondering if it's better using 1/60" with 30 or 60 FPS. I know on paper 60fps is better, but with 60fps I will have the file size that will be double. Thanks a lot!

[@bhongfpv]

I tried recording 4k/30fps on 03 unit.. it was awful flying with 30fps. Because of this im shooting in 60fps

[@erikvf7]

Hello Chris, awesome comparison and explanation! Thanks!! I'm wondering how's the latency with the new 30fps recording modes now, will that double the latency in the goggles as well? Thanks

[@lemonsquareFPV]

100:30 is the ratio you are looking for… and yes latency is about 3X higher in 30fps. Good luck flying that, it would require quite the motivation to make it work, for most it would be unflyable. All the best.

[@erikvf7]

@@lemonsquareFPV hahah, yeah. I'll try that out. Maybe it works for that slow cinematic flight, to get that additional motion blur effect with the 30fps..

[@SkeezyFPV]

Dobo did a test flying the avata in 30 fps. It was horrific lol

[@lemonsquareFPV]

@@erikvf7 please be careful when you fly it, and leave extra space and time for yourself. It is not easy flying properly with that amount of motion blur and latency.

[@Michael9W]

If DJI decide to upgrade Goggles 2 with 120 hz screens how will they name it? Goggles 2 V2? Joks aside, I hope it will be Goggles 2 Lite (let's say no oled, but global shutter and 120 hz)

[@npcfpv9542]

Obviously it would be called "Goggles Also"

[@-exeCy-]

They already have it in mind and they will call it "Gogges 2 SE"

[@rolliseventeen]

should be named Googles NG MK X last edition

[@1337plans]

Does the same latency happen with the Integra goggles?

[@ghiss46]

Thank you for your work ,,Can you test latency with old air unit and goggles 2 vs v2

[@JoeMommaFPV]

Hey Chris great info! I have a question for you though. Did you test this at 2.7k 120 fps? or is that not an option in this new update? As I understand, all 4k recording modes put you at 60fps in the goggles. To keep lowest latency you must use max of 2.7k. I haven't updated yet, so I don't know what new options there are. but if there is a 2.7k 120fps recording option for the goggles two I would be VERY interested to see if it displays still at 100fps in the goggles two.

[@ChrisRosser]

As I understand the resolution is just for the onboard recording (the live feed is always 810p on V2 and 1080p on goggles 2) The frame rate is respected by the live feed in all modes. The goggles 2 support 100hz and 60Hz (50fps is just frame doubling). The goggles V2 support 100Hz and 120Hz (with frame doubling as necessary)

[@JaredMcConnellFerzen]

Could you do a latency test on the HDZ goggles comparing walksnail analog HDZ60 and HDZ90?

[@youzrnaim]

Brilliant.

[@baggszilla]

Thanks Chris so much for this info! Why but why would they give us 120FPS 4K recording and drop us down in the goggles to 60FPS why can't they do it at 100FPS? Because the frames won't line up is my guess?

[@ChrisRosser]

I think the goggles 2 screen only does 100Hz and 60Hz (as of today). 50Hz is displayed at 100Hz (frame doubled) and 120Hz they just discard every other frame. You could drop every sixth frame but that might look a little weird with constantly variable latency and there could be tearing issues.

[@yuranium]

Thanks @Chris for another informative video. Do the same latencies apply at 2.7k and 1080p 120 fps / 100 fps settings on goggles 2?

[@ChrisRosser]

Yes the latency of the live view doesn't seem to depend on recording resolution only frame rate.

[@docmalc47]

@@ChrisRosser I bet when writing the code someone got lazy with variables and constants

[@asifasif-ee2lq]

Hi chris sir, I am facing a problem,,,I am using polar vista with my dji goggles 2,,everything is okay but whenever I take my drone 150m-200m away(fully open space) my signal drops to 5-6mbps,that's unexpected,,goggles 2 has no option to change the milliwatt,,,kindly help me to solve my problem

[@gior12_]

thank you! just a thing, dji o3 goggles 2 4k 100 or 1080 100? which is better for low latency

[@gior12_]

also because in 4:3 you can 100fps only in 2.7k or 1080, but you can see much more

[@maciejdYm]

Do you know what e2e delay is with dii Integra goggles? And what frame rate should we use to get lowest latency in that configuration (O3 + Integra) ?

[@icp-trek]

The O3 system as it is right now is such a compromise. For the least latency, you have to record at 100 fps. But it does not divide evenly to any frame rate other than 50 Hz. Which is only suitable for PAL broadcasts. There needs to be an option to ditch the recording function to have it behave like a regular FPV camera and then record with an additional dedicated recording camera.

[@lemonsquareFPV]

100->50->25, when I had it I used 25fps, and had really good results. Try it, you will likely be happy, just keep every 4th frame and it works really well. But this is for cinematic… never could record freestyle with the system. 60fps video turns out okay, but then flying becomes not fun… quite the compromise.

[@icp-trek]

@@lemonsquareFPV True you could go 25fps. It all depends on what media the content is made for. I just wanted to point out that the system is limited since its used for both viewing and recording. Apparently many like it, just not me. For me the odd frames are too visible.

[@lemonsquareFPV]

@@icp-trek I agree 100% that’s what I was getting at, maybe I didn’t express myself properly. Unfortunately that’s how the system is, and honestly that’s the least of its issues :p I flew 30+ days in the air on the system but gave up and moved on to better things. And that’s okay. It’s the absolute perfect system for a lot of people… I’m just not part of that “lot of people” group. :p All the best.

[@babc142]

The Goggles 2 is such a weird halfway house product. Modernised and squeezed into a tiny consumer package at the expense of optical design, anti-fog, RF performance, and frame rate. And the fact that most people with Western faces find it uncomfortable.

[@lemonsquareFPV]

@@babc142 Fuck O3, and fuck DJI for the shit it does to this wonderful community of pilots we call FPV. Having said that, they are not all bad, I personally don’t want to deal with them anymore, but I won’t tell others not to. The Goggle 2 is actually a pretty good product, the optics are very good and the screens are amazing for the price, if you want a higher refresh OLED the goggle will be over $1500, that’s just not possible, no one would buy it. 100hz is more than enough (the system is not real 100hz anyway), this is fine. Anti fog is honestly average, not horrible. And RF performance is significantly improved over all of their prior systems, that part is actually really good. The nose space is a little small, but the curvature and size is good. I modify the shape of the plastic that touches my face on all of my goggles, so that it fits my face perfectly, that’s not a big deal, anyone can change that easily. If it wasn’t such a slow and poor feeling system in the air, I would be using it right now, I just couldn’t make it work, but the goggle is pretty great!

[@barraca1393]

Great video! Where can we find this 03 camera mount (this soft mounted one) for the AOS 3.5?

[@rolliseventeen]

soft mount better, also on a AOS Frame?

[@barraca1393]

@@rolliseventeen DJI 03 camera needs to be soft mounted for the stabilization work properly.

[@ChrisRosser]

I'm working on this with iFlight right now. Trying to find a solution for all the different cameras that works well. Stay tuned! All iFlight O3 BNFs including AOS have a soft mounted O3 camera at DJIs insistence.

[@barraca1393]

@@ChrisRosser Any chance will be seeing this camera mount selling separately?

[@ChrisRosser]

@@barraca1393 Honestly it's been a real struggle with this O3 launch with the different form factor and mounting requirements (and no clear instruction from DJI). I am hoping to do a O3.1 update which will standardise the mounting and support all the different FPV cameras out there. It'll be a few weeks before that is ready but I'll go as fast as I can. 👷‍♂⚒⚒

[@pauk9638]

Wow! Thanks for the test! So if I understand everything correct: with the googles 2 / 100fps - the latency is the lowest. Does the resolution matter at all?

[@ndcapper]

A week ago I cancelled my Goggles 2 order. This solidifies my decision

[@MajidKhan-ef2zy]

How about if i record on 1080p and 60fps... does it have better latency compare to 1080p 100 fps?

[@Simofly]

So DJI new goggles 2 are slower and we are locked to choose the same refresh settings, aspect ratio and picture settings of the recording as live feed. Getting a live feed to fly safely is different from recording the flight IMHO , this is not a safe system as soon as you want to substitute O3 to an appropriate HD cam.

[@breakflight]

Better yet. Use 1 LED that's picked up by both cameras. The FPV camera can see the single LED. The observer camera can see both the screen showing the FPV feed and the single LED.

[@rolliseventeen]

i was also thinking about this 2. led. why? :-) i would have used a little mirror, if it is not possible to put it perfect in focus.

[@ChrisRosser]

You're right that a single light source would also work in theory. In practice it's much easier to set up one led in front of the high speed and one in front of the fpv cam. The goggle optics need the high speed camera to be where your eye is and the goggle is designed to stop light leakage from outside the goggles. This makes it basically impossible to see the whole goggle screen clearly through the goggle optics and anything else outside of the goggles. It's verifiable that the LEDs in parallel turn on together within much less than 1us. Usually single digit nanoseconds so they are effectively instant for these purposes. Making the two LEDs equivalent to a single source.

[@alejandroiskander1491]

How is the effect of the shutter speed and the framerate of the video recorded by the gopro being taken into account in the latency calculation?

[@ChrisRosser]

If you're using a go pro the frame rate of the go pro doesn't affect FPV latency as they are completely separate cameras. Usually you'll run the Go Pro at 30fps and the FPV cam at 100/120fps.

[@DiraPictures]

Is this the same with the Vista and 120p cam (like wasp) with goggles 2?

[@JS-rh6cs]

Does DJI communicate this also??

[@ChrisRosser]

I don't know! I haven't seen any info from them on this.

[@divingfalconfpv4602]

if u set recording to 2.7k 30fps what is the delay?

[@geehe]

When using 120fps on the O3, DJI is most likely sending one frame out of 2 to the G2 Goggles hence the 60 fps. It's a way to make it work from a single video feed. If it did send 120fps to the G2, it would likely be out of sync with the panel resulting in even worse latency. So yeah, stick to 100fps. DJI could do a better job at explaining latency on their UI.

[@elarkangelmiguel]

hello, i need a little help, i bought a kakute h7 stack with metal 65 amp, i want to make my first 5 inch drone, the motors i have chosen xing2 2207 black 1750kv, i don't use gopro or other camera, i'm learning freestyle, but i fly for fun Not to watch videos, that's why I don't use a camera, what matters most to me is being on the air as long as possible with each battery, 6s is clear to me thanks to your videos Joshua. No matter how hard I search, I can't find recommendations for people like me, who only fly for fun and have doubts about what to build that is really good, and who only fly analogue for weight and that fun. Regards, and thank you very much.

[@ColeCleveland1]

Does recording affect it at all?

[@Sylo2Nice]

Its almost like the V2 goggles are better. I mean if you could fly in 4k low latency mode and cant do it on goggles 2 is weird. Atleast 100 fps would had been nice.

[@matthewbradley8971]

Your forgetting the resolution difference. The V2 at 810p is vastly inferior to the 1080p resolution of the newer goggles.

[@Sylo2Nice]

@@matthewbradley8971 that is correct. The screens look so much better as well. Im just saying for sd card recording. But the V2 can connect to everything fpv. For ppl that only fly the fpv drone and the avata, its a huge plus.

[@amathma]

@@matthewbradley8971 but you see better with the Dji 03 on the v2 than a caddx vista for instance.

[@FPVSlice]

@@amathma I don't know if that's objective. I've seen comparison video's and to me it seems there is way more definition in shadows/branches when using the 'older' system. For sure, the O3 system grants way better picture quality, but i wouldn't call it an upgrade for everyone. I was thinking of upgrading to O3, but i really don't see a reason, to be honest.

[@amathma]

@@FPVSlice I’ve been testing in different situations the DJI 03 on cinebot vs Caddx vista on Nazgul 5 and Protek 35. I can confirm you that it’s an update with better quality in the googles and also on recording video. Plus in most of situation you can do some warm ups/test flight with no go pro on it and then put a GoPro if need it.

[@biggfpv2721]

Have you tried 2.7k 120 and 1080p 120 just curious what those do

[@ChrisRosser]

They operate very much the same as 4k120 fps in my testing. The live feed doesn't respect resolution (that's just for internal recording) it only respects frame rate.

[@lemonsquareFPV]

Confirm camera reads the sensor at only 1080p50hz or 810p60hz 100/120hz is for latency purposes and camera sensor is read only 50/60 times a second.

[@riofpv]

you are comparing a 1080 data stream to a 720 data stream, the test should be done by limiting the O3 to 720 on the goggles 2

[@rolliseventeen]

you cant limit the stream to 720 with the goggles 2. its 1080. and i also think it was not a 720p, because the V2 has 810p display and i think it demands 1080 to get the full 810p according to the specs from dji. otherwise it will pull up a 720p stream to 810p? i dont remember that it will do this. where did you read this?

[@ChrisRosser]

I believe the stream is h265 1080p to the goggles 2 and h264 810p to the fpv goggles V2. This is not currently configurable and independent of recording resolution and fov settings.

[@TheMadmacs]

anybody know if vista transmit 810p on any of the firmwares?

[@zaphyrfpv6671]

you are talking about dji fpv goggles v2 with O3 that dvr is 810p.....other old caddx vista/nebula dvr 720p

[@aerialimagery3216]

Flying the 03 with V2s and the latency feels great with 120 fps mode. Don’t notice any difference over the v1 DJI air unit/ vista. I actually think the 03 latency is more consistent but that might just be me.

[@ChrisRosser]

I would expect you're correct. The O3 RF approach is much more advanced so it probably keeps a more consistent link. Latency on the V2s is very similar to DJI V1 (about 3ms more).

[@filipf.5797]

WTF Latest is not greatest ? That Googles 2 seem to be much worse then older V2.

[@aphinion]

... or when you need those 120fps cinematically ;)

[@BaldmanFPV]

ooff..

[@auckwads8169]

Interesting and odd as i had 120fps 4k from releease day in my options gog v2

[@ChrisRosser]

Interesting! Were you a beta tester?

[@olivierf.4931]

I choose to boycott DJI

[@zaphyrfpv6671]

omg...a lot of seghe mentali.... 1) 4k 120fps O3 + goggles 2 Arm and go flying without no problem. 2) bla bla bla bla and stay at home . make your choice😁😁😁😁

[@riofpv]

🤣🤣🤣🤣🤣❤️

[@hildy2222]

I like how much more stable the latency is on O3. It’s pure butter.