Bad Jello effect on recent video shoot

[WildcatDave]

Actually, jello is exacerbated by higher frame rates especially when coupled with higher shutter speeds (not using an ND filter).

Power Director does not need any external programs or devices to work with any footage for reduction BTW. A Proxy is simply a lower resolution version of the 4K clip. For instance unless and even if, you have a very good computer, scrubbing thru 4K footage on a time line is a big drain and it takes a lot of horsepower in a computer to do it so to speak. In PD when I bring a 4K clip into the library, it will begin to make a shadow (proxy) file of that very clip only at 720 at a fairly high compression. Now I can throw the shadow file onto the timeline and edit at will - effects, color correction , anything but now it will run it and I can scrub back and forth.

When it is time to render out, Power Director renders the full clip not the proxy, so I can select the resolution and all other other specs I want, in your case you would just set it to 1080 and whatever data rate and so fourth and render out.

The subject of ND filters and shutter speeds with video is a deep one and it is not necessarily intuitive. In video; especially like we shoot from a moving platform, motion blur should be present to get a natural look and High shutter speeds and frame rates erode that but I do understand that is becoming a look some want to go for. Here is a frame from a video running 30 FPS, 1/60th and an ISO of 100 which; is what I try to run most times. This is unedited and straight out of the camera. My Plus is orbiting me so everything that is moving in the scene has a natural motion blur while the subject pops into focus.

Thanks for the info on the proxy. That makes sense, I know when I dump new files into a project there's a little icon on each file saying that it's creating a shadow copy or something like that. I would guess that's the smaller workable file.

However I don't really have to worry about processing horsepower. I have a custom-built computer that was over $3,000: including the highest speed samsung nvme drives and a 7820X delidded, overclocked and water cooled, 64GB of RAM, 1080ti video, all the goodies. My other business besides photography is an IT consulting company that I've had for nearly 30 years - nice to have when needing more computing power.

The sun is so darn bright in Arizona that even when running a 4 stop nd16 filter at ISO 100 and shutter speed of 1/60 of a second. I definitely have blown out clouds. I need to get to an nd32 filter if possible, which I see a company called freewell makes but there are some complaints about it being a little heavy on the gimbal but workable. Otherwise I would just rather shoot at a higher shutter speed like I did in my shoots last year. I'm just confused as to why I had many clips previously shot on auto at a very high shutter speed without a single Jello effect at all, whether panning, gliding or manually controlling the flight. But if I can't eliminate the Jello effect I will have to track down that freewell ND32 filter.

 

[WildcatDave]

OK Guys, here is a new test today. Full batteries in the ST16 and the Typhoon H. Did Calibration for: compass, accelerometer, gimbal. Launched drone up 50 feet, up with the landing gear. Set to 4k/30, Auto Exposure -0.5eV. Started recording and used the continuous pan switch at moderate sped. Everything looks great at the start, and then at ~40 seconds the Jello begins. Then towards then end of the video it goes away. I tested other speeds and reversed the pan direction. Sometimes the video is steady and sometimes I get Jello. It can be for the entire video or intermittent, and the effect can be large or small - very inconsistent. It does seem worse (or more noticeable ) when the pan speed is slower. I also test the cruise control (glide) to the left and right at various speeds with NO JELLO effect - this keeps the gimbal at one position and 'slides' the Typhoon left or right. This Jello issue only occurs when panning.

Is it possible my gimbal is jerking a bit during panning, and the CMOS camera readout (which is line by line) is picking this inconsistent panning? I also noticed a few jerky sections of some video where instead of jello it gets a little choppy while panning. I am starting to think my gimbal might be faulty. I also did a 'manual' pan by using the left stick to spin the Typhoon. This was OK, except keeping a consistent spin speed is very hard, and there was slight movement in the drone itself.

Also I wonder if it's happening because I have it set on auto exposure, the camera is adjusting the shutter speed to accommodate the meter adjusting exposure as it moves in relation to the sun. Vs using full manual mode. This variable shutter speed might be why sometimes the jello is present and sometimes it is not. I'm not sure if an auto locks the exposure at the start of the video or if it actually adjusts it during the video. I would assume it adjusts it as needed otherwise what would be the point of Auto. Also if you haven't read all the previous posts, when I use an ND16 - 4 stop filter and manual mode at shutter speed of 1/60 everything seems pretty good. I just have a little bit of clouds being highlight blown out as four stops is not quite enough believe it or not with the Arizona Sun.

Video attached, let me know if the link works, my first ever YouTube upload. You can see the Jello effect start at ~40 seconds.

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[AH-1G]

You may have issues with firmware that's processing the video to you're SD card?

 

[WildcatDave]

You may have issues with firmware that's processing the video to you're SD card?

I would say that's possible however last year I used this exact same Hardware set up: same time of year, same lighting situation, exact same card and did not have the problem. Have not since change the firmware, it's just all the sudden started happening after sitting unused for about 6 months.

I believe I can also visibly see it happening on the screen of the st16 although out in bright light on that smaller screen it's hard to say for sure.

Also for note, the Drone is about a year old has current firmware and has less than 5 hours of Total flight time.

 

[AH-1G]

Six months sitting around.
This I'm not sure of, is there some type of lubricant in the camera to help it spin freely? I know it you let motors sit around for a while the lubricant can get coagulated.

 

[Ty Pilot]

It seems you have a vibration that is just a little too much for the gimbal to dampen out which is why it is coming and going. Your also running auto exposure so your shutter speed is likely very high. I understand it has worked like this before but things can change. SD cards can work great for six months and then all of a sudden not, I just had one fail in a DSLR.

If it were me I would perform a simple test to see if this theory is correct - set the H on a table booted up but engines off then; start recording and do a pan, even pick it up and walk with it, Does that video have jello? If not, check the balance of the propellers and change the SD card no matter what.

 

[WildcatDave]

It seems you have a vibration that is just a little too much for the gimbal to dampen out which is why it is coming and going. Your also running auto exposure so your shutter speed is likely very high. I understand it has worked like this before but things can change. SD cards can work great for six months and then all of a sudden not, I just had one fail in a DSLR.

If it were me I would perform a simple test to see if this theory is correct - set the H on a table booted up but engines off then; start recording and do a pan, even pick it up and walk with it, Does that video have jello? If not, check the balance of the propellers and change the SD card no matter what.

I've had an IT consulting company for 27 years, I'm pretty familiar with memory systems. A card that is going corrupt or has corruption will not cause that kind of Jello effect. The data would be corrupt and likely unplayable not wonky like that. It is either written to the card from the camera correctly or failed. I'll go ahead and try a new card just to be safe. Will also go ahead and do a desktop test with the camera and see if I have better luck. The gimbal does very freely move when it is turned off and it seems to be smooth otherwise, so I don't think it's a lubrication issue.

Thanks for your input I'll report back after the table test

 

[WildcatDave]

I've had an IT consulting company for 27 years, I'm pretty familiar with memory systems. A card that is going corrupt or has corruption will not cause that kind of Jello effect. The data would be corrupt and likely unplayable not wonky like that. It is either written to the card from the camera correctly or failed. I'll go ahead and try a new card just to be safe. Will also go ahead and do a desktop test with the camera and see if I have better luck. The gimbal does very freely move when it is turned off and it seems to be smooth otherwise, so I don't think it's a lubrication issue.

Thanks for your input I'll report back after the table test

It seems you have a vibration that is just a little too much for the gimbal to dampen out which is why it is coming and going. Your also running auto exposure so your shutter speed is likely very high. I understand it has worked like this before but things can change. SD cards can work great for six months and then all of a sudden not, I just had one fail in a DSLR.

If it were me I would perform a simple test to see if this theory is correct - set the H on a table booted up but engines off then; start recording and do a pan, even pick it up and walk with it, Does that video have jello? If not, check the balance of the propellers and change the SD card no matter what.

Also, as relates to the vibration. When I use in nd16 filter and use manual mode 1/60th of a second shutter speed I do not see the jello at all whether I use a slow medium or fast pan. Wouldn't I still see it if I had a vibration issue or a wonky gimbal?

 

[WildcatDave]

Okay just did the desk test. Slow medium and fast pans and they were smooth and Flawless. So I would say the gimbal is fine, the camera and the card are all fine. I'm likely having some kind of vibration or stability issue during the recording that's causing movement in the Drone that's being exacerbated by the line by line read out that the CMOS sensor on the camera uses. And it may have something to do with shutter speed as well. In my office I'm obviously at a significantly lower shutter speed than I would be when I'm out in direct sunlight. Probably similar in shutter speed to the 1/60th I was using with the nd16 filter outside on manual mode.

I'm going to remove the Gimbal and camera have a look at things, try reseating it and see if I can maybe get a test flight in this afternoon again before tomorrow's shoot. Otherwise I'll have to revert back to the ND filter which seemed to cause more noise in the sky than shooting at a higher shutter speed and just the UV filter

 

[WildcatDave]

Also for note I did install a second brand new set of original OEM blades and carefully inspected those

 

[WildcatDave]

I also just noticed this, not sure if this is normal. On my gimbal only two of the corners of rubber mounts have this tiny little pin in the center and what looks like a clip to hold the pin in. The two other corners do not have these extra pieces. I'm not sure if this is normal. Can someone confirm. Maybe I'm missing some pieces of my rubber gimbal support. For what it's worth all of the corners feel the same and the rubber supports seem to be attached properly as far as movement and flexibility between the four corners

 

[Ty Pilot]

Your gimbal is normal, they only ship with two drop down pins. As I suspected; it is vibration, when you use an ND filter those slight registration differences that cause the jello are slightly blurred so the effect is less noticeable.

Also for note I did install a second brand new set of original OEM blades and carefully inspected those

I have balanced all of my props on my 480 and it is rare that one is off by a good bit but I have seen one or two that needed balancing so, if you have a new set you should be fine. I suspect that due to the fact that there are six motors (3 A and 3 B) the reason you are only seeing this effect every so often is that it is some combination of props to motors that is just enough of a harmonic balance that causes the effect. If your desk test was successful I was going to suggest removing and changing positions of the props or bring different ones in for testing. My guess now is that the new props will eliminate the jello.

 

[WildcatDave]

Your gimbal is normal, they only ship with two drop down pins. As I suspected; it is vibration, when you use an ND filter those slight registration differences that cause the jello are slightly blurred so the effect is less noticeable.



I have balanced all of my props on my 480 and it is rare that one is off by a good bit but I have seen one or two that needed balancing so, if you have a new set you should be fine. I suspect that due to the fact that there are six motors (3 A and 3 B) the reason you are only seeing this effect every so often is that it is some combination of props to motors that is just enough of a harmonic balance that causes the effect. If your desk test was successful I was going to suggest removing and changing positions of the props or bring different ones in for testing. My guess now is that the new props will eliminate the jello.

I think I did not communicate correctly. The Jello effect is happening with the new set of props and at this point I have mix and matched the new and the old ones. I guess I could sit there and keep trying to find a good set but I should probably just order a third-set at this point. They're cheap enough but it's worth a shot

 

[Steve Carr]

Just curious. Do you see the jello when panning the camera with the pan knob or only when you yaw the aircraft?

 

[WildcatDave]

Just curious. Do you see the jello when panning the camera with the pan knob or only when you yaw the aircraft?

Hey Steve I'm guessing you probably didn't read through the series of posts. I am only using the pan knob on the Drone and that's creating the Jello effect. I did try to do a manual pan by using the left stick but I found it very challenging to maintain an exact speed due to the sensitivity of the stick.

 

[jandjfrench]

I suspect electrical interference rather than mechanical.

Edit: Afterthought: Checking the relatively low quality ST16 video for the effect might prove helpful in isolating the problem.

 

[WildcatDave]

I suspect electrical interference rather than mechanical.

Edit: Afterthought: Checking the relatively low quality ST16 video for the effect might prove helpful in isolating the problem.

It might be electrical interference. But it's happening at multiple locations both my test site at the park and clients shooting locations. Also what's happening on the st16 screen should not really be indicative as there could be interference transferring from the camera on the Drone to the St16. What gets recorded by the camera stays internal to it and the SD card plugged in.

Additionally I did not see any Jello effect when I'm using the nd16 filter at 1/60th shutter speed. As explained by a few other people that lower shutter speed would mask the issue do to blurring and time enough for the camera readout to be written to the card before the next shutter to avoid slight vibrations.

The new props will be here tomorrow hopefully they will fix this issue. But I'm not so sure that's entirely the problem.

 

[jandjfrench]

It might be electrical interference. But it's happening at multiple locations both my test site at the park and clients shooting locations. Also what's happening on the st16 screen should not really be indicative as there could be interference transferring from the camera on the Drone to the St16. What gets recorded by the camera stays internal to it and the SD card plugged in.

Additionally I did not see any Jello effect when I'm using the nd16 filter at 1/60th shutter speed. As explained by a few other people that lower shutter speed would mask the issue do to blurring and time enough for the camera readout to be written to the card before the next shutter to avoid slight vibrations.

The new props will be here tomorrow hopefully they will fix this issue. But I'm not so sure that's entirely the problem.

I wasn.t necessarily thinking about interference from an external source, but from the drone. Due to the intermittent nature of the problem, I'd be very careful about drawing firm conclusions about any setting changes. I know nothing about the details of the process by which what the lens sees is stored on the drone's SD card. I thought that checking the equivalent video on the ST16 might aid in identifying the problem location in some way. I have nothing more than conjecture but the problem appears very similar to problems I've noted with electronic interference. I didn't read the posts thoroughly but it would be nice to know if anyone experienced a similar effect that was traced to vibration. I am not dismissing vibration as the source of the problem. I am considering its effect on the wire shielding or other electronics and not just the stability of the image falling on the sensor. It would be very helpful to swap the camera and see if the problem remained. I understand how frustrating a problem like this can be and hope it's resolved shortly.

 

[WildcatDave]

I wasn.t necessarily thinking about interference from an external source, but from the drone. Due to the intermittent nature of the problem, I'd be very careful about drawing firm conclusions about any setting changes. I know nothing about the details of the process by which what the lens sees is stored on the drone's SD card. I thought that checking the equivalent video on the ST16 might aid in identifying the problem location in some way. I have nothing more than conjecture but the problem appears very similar to problems I've noted with electronic interference. I didn't read the posts thoroughly but it would be nice to know if anyone experienced a similar effect that was traced to vibration. I am not dismissing vibration as the source of the problem. I am considering its effect on the wire shielding or other electronics and not just the stability of the image falling on the sensor. It would be very helpful to swap the camera and see if the problem remained. I understand how frustrating a problem like this can be and hope it's resolved shortly.

Thanks for your input and insight. I definitely could be something like that. Hopefully not as that could be extremely hard to track down.

 

[WildcatDave]

I went out yesterday for a shoot and decided to try something since I'm only going to be giving 1080 video to the client anyway. I shot in 1080P 120fps, auto, -0.5eV without any problem (jello) at all, and then downsampled to 1080p 60fps for the client. The loss of resolution is slightly noticeable from 4k source material but all the videos of panning regardless of speed or direction were Flawless.

I'm going to go back out today and try a couple more videos at the same location at 4K, auto, -0.5eV and see how things go again. My new props will be in this afternoon and I may go out tomorrow for an additional shoot after they show up if I still have Jello effect at 4K today - which i suspect I will.

If all else fails I will just have to shoot 4K with the nd16 filter and manual: iso100, 1/60th of a second shutter. And try to avoid getting clouds in the shot as they're a bit blown out with our harsh Arizona sun. Or alternatively order the nd32 filter from freewell.