As well as this horizon tilt problem I also have the vertical drop after a sudden stop, but at least can control that by coming to a stop slowly. The gimbal tilt although not there all the time can be annoying when it happens.

@DJI Ken, to clarify, I never said my gimbal guard is far from the front of the P4's camera.  You are confusing me with another poster.  My gimbal guard mounts directly underneath the camera/gimbal.   It does not mount underneath the VPS sensors/cameras.   It was shown to DJI Tim in another thread where I inquired if it would be a good guard to use.  He approved it saying it didn't appear to be interfering with anything.  

Aardvark Posted at 2016-5-25 00:40
As well as this horizon tilt problem I also have the vertical drop after a sudden stop, but at least ...

A minor altitude adjustment from fast to a sudden stop can be expected because of the sonar going waves going from an extreme angle to level.
If a IMU and gimbal calibration does not fix what you are seeing then your aircraft would have to be sent in. Can you also post a quick video clip from the SD card as that shows the picture doing the same as how it was when you were holding it in your hand.
I have the DAT file and forwarded it on.If the gimbal tilt went left from you adjusting it and then bounced back a few seconds later then I would say in all the calibrations didn't clear it up then you need to send it in.

The video clip I posted in drop box is the 4k video clip from the sd card and can be viewed properly when downloaded. It doesn't display too well in dropbox. Do you want a clip from that showing me rotating aircraft ?

Regarding the gimbal, I made no adjustment other than rotate the aircraft in the hope that the gimbal might automatically level, which initially it seems to have done (@ 46 seconds).

Thank you for forwarding the DAT file, I shall wait and see what the outcome of the analysis is.

http://forum.dji.com/thread-53496-1-1.html

DJI-Ken Posted at 2016-5-24 15:52
I had not known you have already sent something in. I am in the US but I can still have a DAT file  ...

Ken I've had this problem with BOTH Phantom 4 drones, the first I returned due to spots on the camera sensor.  Surely you have enough people complaining about this problem to realise that it needs to be addressed at a wider level than case by case?
You're asking us to provide DAT files, and I'd love to, but the DJI Assistant 2 software just hangs when I try to go to that section.  Plus I would have thought that the DAT file can't really be trusted as it will show no alteration in height even though the P4 is dropping and raising.
I've witnessed my P4 on several occasions now slowly drop and rise back up with no input and whilst reporting no change in altitude in DJI Go, and this isn't when stopping from speed, merely hovering in place.  The only reason I haven't been more vocal is that I assumed after Tims post the DJI were taking this seriously and addressing it in the next firmware.  Now you post that nothing is being done about it via firmware and that DJI will only deal with it on a case by case basis after supplying videos and DAT files?

What on earth is going on at DJI? You have a thread FULL of people complaining about this problem. That alone should be enough for DJI to investigate it and put it right!

I'm starting to think about returning this P4 to the Apple Store for another replacement, and continuing to do so until I get a P4 that doesn't exhibit this problem, as you seem convinced that this is a rare problem.  
[EDIT] As has already been pointed out, I'm not willing to lose my Phantom 4 for upward of two months for DJI to take a look at it.  I bought it from an Apple Store and they have an excellent returns policy, if this problem is as rare as you say it is then a(nother) return to Apple should bag me a P4 without this issue.  I'm not going to hold my breath though[/EDIT]

Thank you for the update DJI-Ken.

Could you also update us on DJIs plans / progress  to add an option to disable VPS in the DJI  go app on the Phantom 4. I am sure many people would appreciate this option that as we all know is a feature of the Phantom 3


Cheers
John

Advocate Posted at 2016-5-25 02:39
Ken I've had this problem with BOTH Phantom 4 drones, the first I returned due to spots on the came ...

Again, DJI needs data to analyze something to see if it's a wide spread issue.
With lots of people saying they have an issue doesn't cut it. That is why I am asking for data to give to them so they will investigate.
I don't know what the turn around time is in the UK but in the US it's only 1 to 2 weeks so if my aircraft had an issue I would send it in to be checked out/repaired.

johnlynas666 Posted at 2016-5-25 03:00
Thank you for the update DJI-Ken.

Could you also update us on DJIs plans / progress  to add an opt ...

I'm sorry, at this time there is no movement on disabling it.

Hi Ken

here is tonights flight

https://www.dropbox.com/s/d53epf ... 9-18-50%5D.DAT?dl=0

lots of stopping and dropping, will get some video when i have someone with me

Hi Ken,
Hi Ken

On a P4 are obstacle avoidance and VPS part of the same subsystem or are they independent of one other ?

if  I  turn off  Obstacle Avoidance on the P4 does this  also turn off VPS on the quadcopter ?

DJI-Ken Posted at 2016-5-24 20:38
Again, DJI needs data to analyze something to see if it's a wide spread issue.
With lots of people ...

Any tips on fixing DJI Assistant so I can actually get at the DAT files then?
[EDIT] And actually lots of people saying they are having a problem should cut it Ken, generally people don't complain unless they actually do have a problem.  This doesn't cut it attitude is tantamount to calling your customers liars. I appreciate DJI may need data to analyse but a better approach would be "I'm sorry you're having problems, can we look at your log files to see if we can figure out what's going on?" Especially with a thread this long about a problem that lots of people are saying they have. [/EDIT]

A P4 friend text me earlier and asked me if I had the dropping problem, I said I had not really noticed it so took it out just then and raised to 20m and full throttle forward for 25m and let stick go, it just stops with no dropping, I tried it 5 times and all the same, no dropping, just thought I would put it on here too.

johnlynas666 Posted at 2016-5-25 04:14
Hi Ken,
Hi Ken

Yes, they are two separate systems. The obstacle avoidance is the two front cameras. The VPS is the two cameras and two sonar sensors on the bottom.
So if you turn OFF obstacle avoidance it does not turn off the VPS.

mark.mwilliams7 Posted at 2016-5-25 03:50
Hi Ken

here is tonights flight

Perfect, thank you very much.
I won't have answers immediately as I am sending these to China and not the analysis team here.

Weather permitting I will take my Phantom 4 out tomorrow, with my Canon 5D MKIII and try and get some video of it not maintaining altitude, and then send the video files and DAT file (if I can get at it) to you for analysis.

Advocate Posted at 2016-5-25 04:17
Any tips on fixing DJI Assistant so I can actually get at the DAT files then?
[EDIT] And actually l ...

There is nothing wrong with the DJI Assistant.
Are you using PC or Mac?
Sometimes it can take up to 5 minutes for the computer to recognize the P4 so give it time.
You can try to delete and reinstall the program and also make sure your security settings allow the P4 to be connected.
If your on Mac then you have to install the driver as well as the program where PC does both for you.

mark.mwilliams7 Posted at 2016-5-25 03:50
Hi Ken

here is tonights flight

Your link is not working.

DJI-Ken Posted at 2016-5-24 21:26
There is nothing wrong with the DJI Assistant.
Are you using PC or Mac?
Sometimes it can take up t ...

Thanks for the Assistant tips Ken, I believe I have installed the driver already as the other functions of the Assistant app seem to work fine. The only other file I can see is an android driver file, that wouldn't be it would it?

DJI-Ken Posted at 2016-5-24 21:22
Perfect, thank you very much.
I won't have answers immediately as I am sending these to China and  ...

Ok great be good to here what's said

Do you still need some video?

Ken, if I can get at them is it worth sending you any DAT files that I already have?  My P4 has exhibited altitude drops on every flight that I have taken it on.

Advocate Posted at 2016-5-25 04:29
Thanks for the Assistant tips Ken, I believe I have installed the driver already as the other func ...

It's not an app, it's the computer program. You've download it from this page correct either for PC or Mac?
http://www.dji.com/product/phantom-4/info#downloads

I don't know how you would see an Android driver.

mark.mwilliams7 Posted at 2016-5-25 04:31
Ok great be good to here what's said

Do you still need some video?

Did you see my post, the link to the DAT file is not working.Can you please relink it, thanks.

Advocate Posted at 2016-5-25 04:36
Ken, if I can get at them is it worth sending you any DAT files that I already have?  My P4 has exhi ...

Yes, any DAT file will work. Please post a link and if you do happen to know where in the DAT file the drops were that would help.
Thanks

When you install the driver on OS X the first screen explains that it's a driver for connecting Android phones to OS X. I guess the P4 uses Android?

Ok I'm currently uploading a 2.8gb dat file to my Dropbox and I'll post a link when it's done.  I'm afraid I can't pinpoint when the drops were unfortunately so I don't know how much use it will be but I will try and get out tomorrow and provide some more useful data.

Advocate Posted at 2016-5-24 22:14
Ok I'm currently uploading a 2.8gb dat file to my Dropbox and I'll post a link when it's done.  I'm  ...

You realise some poor sods got to sift through that, mine was only 430MB

I just noticed this issue with the drops last weekend. I've had my P4 3 weeks and it came with the current firmware. For the first 2 weeks it was rock solid and then a week ago I noticed the yo-yo effect about 130ft  up.  I grounded it and the next day it was fine. Then this past weekend I noticed some drops close to the ground where it would drift down and almost touch the ground. I looked on here and other online sources and saw that this is a wide spread issue. I took it out Sunday and watched it go up and down about 30-40ft over and over again. It was up at least 100ft at the time. I refreshed the firmware, calibrated everything and tried again yesterday.  It seemed okay with only a few minor drops (as far as I am concerned it should not drop at all), I flew around and then hit the return to home.  As it came in to land it started to drop extremely fast and I pushed the stick up in time to save it. It landed with a bounce but no damage. When I looked at the replay in the app, it said it shut down at 124ft. SO basically it didn't know how high it was. I immediately called the DJI support (USA) and the guy said to roll back the firmware and wait for an update. I explained that it was fine with the current firmware until a week ago but he insisted I should roll back the firmware and try it.  I did, same altitude drops.  Everyone seems to think this is a firmware issue but mine worked fine and then it didn't all with the same firmware.  Rolling it back didn't change anything. It doesn't seem that DJI's support are on the same page either.  This is my first DJI, several of my friends want one after seeing mine but now I am warning them against it.

For the record, I have also seen drops in altitude with mine plenty of times, sometimes even when it is just hovering. At some point I will try and get someone out with me to film using my dslr and a long lens.

As someone who is new to flying it is pretty disconcerting! I've also had the gimbal tilt at times, it went way out today on one flight.

Now's your chance guys, get the DAT files to DJI with video evidence if available, the horizon tilt and vertical drop almost seem endemic in the P4's. The more the merrier.

Because the Phantom 4 is my first drone I assumed the altitude drops and (far less with this one than my first) occasional gimbal level problem were just part of drone flying.  It is only because I believe in seeking out forums like this for advice and support that I found out that it's not normal behaviour.  As I said earlier, because DJI Tim had said they were aware of the problems and we're working on a fix I assumed I could just await the fix, and indeed was one of the people pushing for others to calm down about it and give DJI the time they needed to implement the fix.

That's why I was a bit put out tonight when DJI Ken said the opposite to DJI Tim, and that this wasn't a known problem with the Phantom 4, that he'd only seen a couple returned for these problems and that as far as he was aware there was no firmware fix coming soon.  My apologies to Ken if I was a bit abrupt about it.

I love my Phantom 4, and am more than happy to supply DAT files and videos to help identify and fix the cause of these problems, I just wish I'd known sooner that they needed us all to supply them.

I can't wait to see how my Phantom 4 performs when these problems are fixed.

DJI-Ken Posted at 2016-5-24 21:26
Your link is not working.

https://www.dropbox.com/s/d53epf ... 9-18-50%5D.DAT?dl=0

Try again sorry

Advocate Posted at 2016-5-24 23:36
Because the Phantom 4 is my first drone I assumed the altitude drops and (far less with this one tha ...

I'm completely with you on this one, with the same experience and expectations. This surely cannot have run to 6 pages of comment without there being some issue, one which, as you, I believed was being researched and resolved. Indeed another forum user had posted an email apparently from a DJI engineer indicating a solution was in hand to the gimbal tilt problem. Twice that email was removed, which does nothing to inspire confidence. I can understand DJI wishing to protect their flagship, but not in such a blatantly obvious manner.

mark.mwilliams7 Posted at 2016-5-25 06:39
https://www.dropbox.com/s/d53epfj7u1m9s82/DJI_ASSISTANT_EXPORT_FILE%5B2016-05-24%2019-18-50%5D.DAT ...

Perfect, thanks. I'll forward it on right now.

Aardvark Posted at 2016-5-25 06:20
Now's your chance guys, get the DAT files to DJI with video evidence if available, the horizon tilt  ...

The reason I need videos, you saw the other thread with the tilted horizon. I already said I think it's the terrain that is sloping and that's why it looks tilted. Look at the bottom of the clouds, they are perfectly level with the sky. So if the camera was tilted then the base of the clouds would be as well.
And that's why I need videos and DAT files.

DJI Ken is correct regarding the gimbal/camera guard causing altitude Yo-Yo in my Phantom 4.  I just returned from flying 3 batteries in my P4 with the aftermarket gimbal guard I purchased.  It is a fine looking gimbal guard, carbon fiber and does not extend beneath the VPS system.  Fits neatly directly underneath the P4's camera gimbal.  However, the VPS does see it.  After flying my P4 and experiencing the same behavior as displayed in my video, I landed and removed the gimbal guard.  I then flew 3 batteries in the same location I created the video of the Phantom 4 Altitude Yo-Yo.  The P4 flew stable and smooth.  However, the operation of the Phantom 4 over water is not without issues.  I discovered that the P4's VPS system actually sees the water and drifts slowly, side to side, at about 0.2 mph as indicated on the DJI Go app.  Increasing altitude to about 50 feet seemed to be the "sweet spot" for complete stabilization.  Bringing it down lower disrupts it somewhat, but, low altitude rise is the typical reaction and drift.  Some altitude drop was also seen, but, getting lower it would sense the water due to prop wash and raise altitude and drift.    Nothing drastic and uncontrollable, but, it is there.  Flying at low altitude over the water is not an issue in my unit until you release the controls.  Then, you may see some erratic behavior.  My suggestion is for people filming over water that you maintain an altitude of 20 feet or greater while shooting video.  Framing a photo and holding altitude/position can probably be done at about 35-40 feet with some patient positioning.  At 50 feet the Phantom 4 definitely does not see the water and remains stable in both altitude and position.  One "like new" carbon fiber and machined aluminum gimbal guard for sale!  (My apologies to DJI Ken for questioning his knowledge of the issue and solution.  DJI Ken definitely knows the systems of the Phantom 4!)  I will post my video of the Altitude Yo-Yo Incident this evening or tomorrow.)

bengalboy69@gma Posted at 2016-5-25 03:34
DJI Ken is correct regarding the gimbal/camera guard causing altitude Yo-Yo in my Phantom 4.  I just ...

It's great that DJI Ken sorted your problem fella, I'm pleased for you, and we're lucky to have Ken and others like him on these boards to help us out.  I really hope there's just as simple a fix for the rest of us.

Aardvark Posted at 2016-5-24 19:03
I'm completely with you on this one, with the same experience and expectations. This surely cannot  ...

There is indeed an issue, in fact several.  The gimbal tilt and altitude drop is affecting a large number of users and DJI acts like they have no clue what is going on.  They're stalling and it appears to be a hardware issue and I wouldn't be the least bit surprised we're all royally screwed on this.

They act like they have never seen it before and it's ALL over the web and Youtube.   You think that after returning a P4 3 times to Apple you would get at least one of them to work but they all have the same issues.

Fix the problem DJI and quit stalling.

Took my flight data into phantom log viewer from last night and its clear that when it stops it drops, the first line is altitude in meters the other is speed in mph, so when the speed is zero look at the drop in altitude with no input from me.

now this flight was me just flying a squire patteren with stops 90 degree turn fly off and stop, different altitudes just to see what data i could get

DJI-Ken, I have a question as well.
I know this is a wrong thread, but still.
What about horizon level on a gimbal problem? Is it software or hardware problem?
If it is software, when will the update be available? This is nonsense! One thing this drone should do is shoot great photos and videos and, hell, even here it has a problem.