Just wondering if anyone is experiencing a blurry/smudgy area in their video footage. It doesn't appear in still images. It only appears when shooting video at f/9.0 or higher and it's located in the lower right side of the frame.

Example of blurry spot

Hi there. We're deeply sorry for the trouble. Could you please upload the original file showing the issue via Google Drive and send the link to us so we can check? If you provide different images showing the same issue, that would be helpful. Also, please try to wipe the camera with a clean cloth and have a test flight again to see if the issue persists. Please keep us posted. Thank you for your cooperation.

DJI Paladin Posted at 2023-10-10 23:06
Hi there. We're deeply sorry for the trouble. Could you please upload the original file showing the issue via Google Drive and send the link to us so we can check? If you provide different images showing the same issue, that would be helpful. Also, please try to wipe the camera with a clean cloth and have a test flight again to see if the issue persists. Please keep us posted. Thank you for your cooperation.

Sorry for the delay. Oh believe me, I've cleaned the lenses and the lens cover repeatedly because initially, I thought that was the problem. However, after several tests, the blurry area is always present when shooting video at f/9.0 or higher. It's always in the same location of the video frame too. Where can I send the link to the original video?

In the past I've experienced blurry areas on photos, which resulted in swapping the drone twice to get a acceptable unit.

I suppose you use a ND filter, so you didn't need to use small apertures?

MS Posted at 3-25 11:05
In the past I've experienced blurry areas on photos, which resulted in swapping the drone twice to get a acceptable unit.

I suppose you use a ND filter, so you didn't need to use small apertures?

If the lighting warrants using ND filters, then I'll use them. However, they aren't needed or wanted in some situations. Any video footage shot at f/9.0 or narrower results in a blurry patch in the same area of the frame. This particular clip was shot at ISO 100, 1/120, f/11.0

a_ambrose Posted at 3-25 08:19
Sorry for the delay. Oh believe me, I've cleaned the lenses and the lens cover repeatedly because initially, I thought that was the problem. However, after several tests, the blurry area is always present when shooting video at f/9.0 or higher. It's always in the same location of the video frame too. Where can I send the link to the original video?

Thank you for keeping us posted. You may upload the video via Google Drive or Youtube then send the link here so we can check the video. Please keep us posted.

DJI Paladin Posted at 3-27 21:36
Thank you for keeping us posted. You may upload the video via Google Drive or Youtube then send the link here so we can check the video. Please keep us posted.

Here's a 25 second clip. The blurry area is circled for reference then the circle disappears after a few seconds. Probably goes without saying, but you should download the file to get the clearest footage.

https://drive.google.com/file/d/1_R8Z5X2NUa93rMZrKtEU1Z4tqvayKFda/view?usp=drive_link

a_ambrose Posted at 3-25 17:53
If the lighting warrants using ND filters, then I'll use them. However, they aren't needed or wanted in some situations. Any video footage shot at f/9.0 or narrower results in a blurry patch in the same area of the frame. This particular clip was shot at ISO 100, 1/120, f/11.0

Not to jump on you again about your technique, but from a professional point of view and from someone who spent a lot of time figuring out that the aperture will absolutely affect the quality of your image, I wouldn't suggest going anything above f5.6, maybe f8.

Small(ish) sensor and a tight aperture is not a good combo for film, especially drones. Gert some good DJI ND filters, lower the fstop on there and your footage will be fine.

People seem to freak out about filming wide open, but with drones the focus at f2.8 is probably about 30ft to infinity which is fine for most situations.

Looking at the footage: I think you might have something on the sensor and when shooting with such a tight aperture it's able to bring it out a lot more in the footage. I'd be interested to see a similar shot at f2.8. Either way - might be worth returning it to DJI.  

Another observation, don't film in h.264 for what you're asking from the footage (60fps 4K). I think you're getting away with it because it's in 8bit, but the second you go to 10bit that footage may fail to play. H.265 is a much more efficient and reliable codec. There will be no visible difference in the footage, it will however play back much more reliably.

CloudVisual Posted at 3-28 10:53
Looking at the footage: I think you might have something on the sensor and when shooting with such a tight aperture it's able to bring it out a lot more in the footage. I'd be interested to see a similar shot at f2.8. Either way - might be worth returning it to DJI.  

Another observation, don't film in h.264 for what you're asking from the footage (60fps 4K). I think you're getting away with it because it's in 8bit, but the second you go to 10bit that footage may fail to play. H.265 is a much more efficient and reliable codec. There will be no visible difference in the footage, it will however play back much more reliably.

Thanks for the feedback. I don't interpret it as "jumping on me". I'm open to improving and you seem to provide good feedback that isn't condescending. I appreciate that. I've been doing this for a long time (before drones) but I'm definitely open to constructive advice. I've only had the Mavic since July so I'm still figuring things out.

I noticed this blurry spot early on and thought it was something on the lens cover, but I've cleaned it multiple times and it's not the lens cover. I even recorded footage without the lens cover and the blurry spot is there. I came to the same conclusion that you stated -- something is on the sensor and the tight aperture is able to bring it out. I've started using the DJI ND filters that came with the Mavic and opening the aperture which seems to fix it.

Just an FYI, this footage isn't straight out of the drone. I clipped it down in Premiere Pro and exported it.

So what do you suggest always filming in?

Thanks for the input!

a_ambrose Posted at 3-28 11:52
Thanks for the feedback. I don't interpret it as "jumping on me". I'm open to improving and you seem to provide good feedback that isn't condescending. I appreciate that. I've been doing this for a long time (before drones) but I'm definitely open to constructive advice. I've only had the Mavic since July so I'm still figuring things out.

I noticed this blurry spot early on and thought it was something on the lens cover, but I've cleaned it multiple times and it's not the lens cover. I even recorded footage without the lens cover and the blurry spot is there. I came to the same conclusion that you stated -- something is on the sensor and the tight aperture is able to bring it out. I've started using the DJI ND filters that came with the Mavic and opening the aperture which seems to fix it.

My best idea to work out if this is a sensor issue is to maybe look at getting the drone on the bench, get something like a camera calibration chart printed out and take some video at f2.8 and then f11, keep the ev consistent across the clips, the framerate won't matter here, but I'd use the stock clear DJI filter in both clips. Hopefully the camera chart will show the blurry spot. I would also see if this issue shows up with images, again a 2.8 and 11 test, perhaps even push the aperture higher if it will allow it. This is probably the evidence you'll need to send to DJI for a replacement.

If that sounds like a lot of effort, then just open a ticket with DJI and show them your video. You open support tickets through the repair site: https://www.dji.com/support/repair

As for how to film with your footage, it's really down to personal preference. I'm not sure what your use case is for your drone. A lot of people film in 60fps because they think more frames equals more amazing footage, but if you're a filmmaker you'll probably appreciate that 24fps gets that film look, but can look choppy. I'm forced to film at 25fps for any TV/FIlm work, but prefer 30 for any of my personal work.

What's important is the codec. h.264 is quite old and isn't able to keep up with the new camera specs. If you shoot 4k in D-Log, that will be in 10bit and it'll record just fine, but on playback you'll find it will stutter or even fail altogether. I've commented on countless threads where someone's footage was corrupt and it's either the codec or the SD card, but in every case someone shot in h.264 it was the codec. h.265 is capable of everything that h.264 can do, but will support 10bit and above 4K.

CloudVisual Posted at 3-28 12:21
My best idea to work out if this is a sensor issue is to maybe look at getting the drone on the bench, get something like a camera calibration chart printed out and take some video at f2.8 and then f11, keep the ev consistent across the clips, the framerate won't matter here, but I'd use the stock clear DJI filter in both clips. Hopefully the camera chart will show the blurry spot. I would also see if this issue shows up with images, again a 2.8 and 11 test, perhaps even push the aperture higher if it will allow it. This is probably the evidence you'll need to send to DJI for a replacement.

If that sounds like a lot of effort, then just open a ticket with DJI and show them your video. You open support tickets through the repair site: https://www.dji.com/support/repair

As for testing the different apertures, I've already done this. That's how I came to realize the blurry spot appears in the same location at f9.0 or tighter. I chatted with DJI a few months ago and they agreed to let me send it in for warranty repair/replacement. It's just that I'm very busy with this drone and don't have a backup for when this one would be shipped off.

CloudVisual Posted at 3-28 12:21
My best idea to work out if this is a sensor issue is to maybe look at getting the drone on the bench, get something like a camera calibration chart printed out and take some video at f2.8 and then f11, keep the ev consistent across the clips, the framerate won't matter here, but I'd use the stock clear DJI filter in both clips. Hopefully the camera chart will show the blurry spot. I would also see if this issue shows up with images, again a 2.8 and 11 test, perhaps even push the aperture higher if it will allow it. This is probably the evidence you'll need to send to DJI for a replacement.

If that sounds like a lot of effort, then just open a ticket with DJI and show them your video. You open support tickets through the repair site: https://www.dji.com/support/repair

I want the best footage possible and I totally understand the 60fps vs 30fps vs 24fps conversation. I typically shoot 60fps in case I want to slow it down but I don't always shoot 60fps. My sequences are typically 30fps or 24fps.

As for D-Log, I haven't really experimented with it but I have shot some D-Log M with the ND8 filter. It was a color correcting nightmare for me. I definitely prefer the normal color mode but understand the flexibility log can give in post. However D-Log M was a bear to color correct.

Thanks again!

a_ambrose Posted at 3-28 12:36
I want the best footage possible and I totally understand the 60fps vs 30fps vs 24fps conversation. I typically shoot 60fps in case I want to slow it down but I don't always shoot 60fps. My sequences are typically 30fps or 24fps.

As for D-Log, I haven't really experimented with it but I have shot some D-Log M with the ND8 filter. It was a color correcting nightmare for me. I definitely prefer the normal color mode but understand the flexibility log can give in post. However D-Log M was a bear to color correct.

DJI have really nailed the colours in the newer drones. If I 'm filming for work then it's in D-Log, but for any of my stock filming, the stuff that comes straight off the camera is better than I can grade. It's an art to be able to correctly colour grade, but that's why my work goes off to be edited by someone who knows how!

In terms of 'best footage possible' some people will say that 60fps captures as much data as possible, so that's right for that purpose. Again, I don't know what your use case is, but if you need as much data as possible over quality, then 60 might be right. Having looked at your footage data (and one of my long standing beliefs) I saw that the bitrate was at 63.5Mb/s. Having looked at my own footage at 30fps, it's around 101Mb/s. So in reality what that means is that per second my 30 frames are receiving a higher bitrate per frame than your 60 (3.3Mb per frame versus 1.05Mb).

I'm fairly sure I've brought this up in the past and someone has said I'm totally wrong, but this was something I could visibly spot when the Phantom 4 which could shoot 60fps came out. I got excited to try it and the footage just looked like it was halving the bitrate to allow the framerate to happen.

CloudVisual Posted at 3-29 01:33
DJI have really nailed the colours in the newer drones. If I 'm filming for work then it's in D-Log, but for any of my stock filming, the stuff that comes straight off the camera is better than I can grade. It's an art to be able to correctly colour grade, but that's why my work goes off to be edited by someone who knows how!

In terms of 'best footage possible' some people will say that 60fps captures as much data as possible, so that's right for that purpose. Again, I don't know what your use case is, but if you need as much data as possible over quality, then 60 might be right. Having looked at your footage data (and one of my long standing beliefs) I saw that the bitrate was at 63.5Mb/s. Having looked at my own footage at 30fps, it's around 101Mb/s. So in reality what that means is that per second my 30 frames are receiving a higher bitrate per frame than your 60 (3.3Mb per frame versus 1.05Mb).

Trying to color correct and grade D-Log especially with footage taken from my neck of the woods at this time of year is a bear. I feel better about my footage shooting in normal mode and my customers know no different nor do they care. If I had a client who wanted log footage so they could color correct and grade it, then I'd shoot it for them.

"Having looked at your footage data (and one of my long standing beliefs) I saw that the bitrate was at 63.5Mb/s."
This clip was exported from Premiere at 60Mb/s. I didn't want to upload the entire clip so I cut it down and exported it with settings I thought were sufficient to show the blurry area.
Thanks!

a_ambrose Posted at 3-28 07:04
Here's a 25 second clip. The blurry area is circled for reference then the circle disappears after a few seconds. Probably goes without saying, but you should download the file to get the clearest footage.

https://drive.google.com/file/d/1_R8Z5X2NUa93rMZrKtEU1Z4tqvayKFda/view?usp=drive_link

Thank you for the information provided, a_ambrose. My apologies for the issue. Can you please have a test flight again and upload the original video files that came with the SD card so we can double-confirm the issue? We will for your response so we can proceed with the investigation. Please keep us posted.

a_ambrose Posted at 3-29 06:49
Trying to color correct and grade D-Log especially with footage taken from my neck of the woods at this time of year is a bear. I feel better about my footage shooting in normal mode and my customers know no different nor do they care. If I had a client who wanted log footage so they could color correct and grade it, then I'd shoot it for them.

"Having looked at your footage data (and one of my long standing beliefs) I saw that the bitrate was at 63.5Mb/s."

Makes sense with the bitrate, I did think that was a bit low per frame, but my beliefs on the 60fps and subsequent divided bitrate still stand.