dirkclod
Premium Pilot
I'm sorry I'm tired of the tilted horizon
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It's not just P3. I have P2V+ and I have almost all the time. It is minor, but still there.
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I was wondering if it was worse on the P3 than P2V+ - I had my P2V+ go off level at the same time a bunch of other stuff started acting quirky - updated and re calibrated the compass and it all went away.
Pointing north when calibrating didn't make any difference for me, ymmv. I have gotten used to manually adjusting the gimbal at the beginning of each flight. It's always the same correction value, -.08.
I imagine an image taken from a P2V+ with a fish eye lens, the horizon slant issue is not going to be very noticeable anyway...
I've been doing manual adjustment before taking off. (I didn't get around to doing a proper IMU calibration yet...)
I did a couple cold IMU calibrations and gimbal calibrationson level surfaces. The result was alway the same. Now I just do a -1.4 or -1.6 gimbal adjustment before every take off. That gives me a level horizon most of the time. I do have the grid configured on in the display so I can accurately check the horizon before a shot and make further adjustment as needed. It is a PITA and I wish they'd fix it but at least there is a work-around.
I'm more annoyed by compression artifacts. I should put this in its own thread but I often get a compression artifact on highly detailed surfaces like grass or trees. The brightness on those surfaces rapidly fluctuates while flatter surfaces remain steady. I have tried a lens shield to verify that it isn't related to prop shadows on the lens. I haven't found a work-around for that. I'm investigating options for trying to correct it in post.
I can live with the horizon issue because I can correct it with a gimbal adjustment before a shot. The compression artifacts are a worse problem for me because I haven't found anything I can do about them.
Joe
I'm more annoyed by compression artifacts. I should put this in its own thread but I often get a compression artifact on highly detailed surfaces like grass or trees. The brightness on those surfaces rapidly fluctuates while flatter surfaces remain steady. I have tried a lens shield to verify that it isn't related to prop shadows on the lens. I haven't found a work-around for that. I'm investigating options for trying to correct it in post.
I can live with the horizon issue because I can correct it with a gimbal adjustment before a shot. The compression artifacts are a worse problem for me because I haven't found anything I can do about them.
Joe
Joe, are these artifacts visible in the actual recording on your SD card, or just what's displayed on your tablet / phone?
I've noticed that the phantom's video codec operations overheat the graphics processor when I'm flying close to tall grass or repeating patterns (like roof shingles); but that's too be expected... as video compression takes a lot more power when handling fine details and repeating patterns. In any case, although the view on my phone and tablet gets artifact, the actual recording on the SD card is fine...
I think we can all agree that Dji needs to come up with a fix release ASAP.
And while you're at it. Release advanced SDK!
And while you're at it. Release advanced SDK!
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I also have this problem, brand new P3.
Has everyone complaining here also reported it to DJI?
Has everyone complaining here also reported it to DJI?
Sorry to be slow responding. I didn't notice the reply.
I've never noticed the artifacts from the tablet while streaming. It is only when I pull out the SD card and view it on a 4K projector. I haven't done any processing to the video. I am viewing exactly what was recorded. I have tried 4K 30 fps and 4K 24 fps. I saw artifacts in both.
My first thought was that it was shadows from the props so I bought and tried a lens shade. That didn't make a difference. I flew on a cloudy day facing north and still saw the artifacts.
Joe
Tilted horizon - yes IMU and gimbal calibration keeps it in check.
I am more (equally) frustrated by the lens distortion. The horizon has a "nice" peak towards the center of the frame and then tails off on both ends. I don't recall seeing this effect in many videos I have watched on YT etc.
I will try to screen grab a video from last evening.
I am more (equally) frustrated by the lens distortion. The horizon has a "nice" peak towards the center of the frame and then tails off on both ends. I don't recall seeing this effect in many videos I have watched on YT etc.
I will try to screen grab a video from last evening.
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Assuming you have already done the IMU calibration and gimbal calibration, the only thing left is the gimbal adjustment setting. Unfortunately it isn't retained when the Phantom is powered off. I have made that part of my pre-flight procedure and I check it again in the air before shots where I want to make sure the horizon is level.
We're all hoping that DJI fixes this in a firmware update or at least makes the gimbal adjustment retained once set.
Joe
Tilted horizon - yes IMU and gimbal calibration keeps it in check.
I am more (equally) frustrated by the lens distortion. The horizon has a "nice" peak towards the center of the frame and then tails off on both ends. I don't recall seeing this effect in many videos I have watched on YT etc.
I will try to screen grab a video from last evening.
That's just standard lens distortion, g00se. This camera just uses cheap plastic lenses. (One reason I'm somewhat amused by the frenzy to attach ND filters as though people fancy they're using a $50,000 cinematic studio camera for slow frame rates from an aerial perspective). It's more apparent when the horizon is high (or low) in the frame. There's very little distortion in the center of the frame so you won't see that bulge on videos where the horizon is centered. Others may have removed the lens distortion with their video editor.
In any case, rest assured your camera is not flawed--at least not worse than the rest of us.
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Seems many are having this problem. Mine does not so I can't test this.
I wonder if you do the IMU on a level surface but shim the one side slightly and then do the gimbal calibration.I think shim the side that is wide on horizon.
In g00se 's video shim the left side to give the surface about a 2 degree angle.
Seems the gimbal hang is off by that much.
I wonder if you do the IMU on a level surface but shim the one side slightly and then do the gimbal calibration.I think shim the side that is wide on horizon.
In g00se 's video shim the left side to give the surface about a 2 degree angle.
Seems the gimbal hang is off by that much.
The fish eye distortion is more due to the short focal length (wide angle) lens. It is the equivalent of a 20mm lens on a 35mm camera which would also cause considerable geometric distortion. For stills, the program Lightroom has profiles for a huge number of lenses so that it can correct distortion. It does have a profile for the Phantom 3 which does a nice job.
Joe
Joe
@skyeboysteve -- Thanks for the reply.
It makes sense the distortion would be less if the horizon is centered. I think I tend to pan down to keep the rotors clear of the video and that pushes the horizon up in the frame. The pic above was cropped to remove the lower 2/3 of the frame.
I haven't progressed to video post-processing (yet).
Tried it. Doesn't work. For most it's not a fix till but gas a mind of its own when yawing
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