working with 4k footage in post....some issues.
4932 20 2015-3-26
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Redeye
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United Kingdom
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Need some advice in getting rid of some issues iam having with film output.

Ive only been flying the inspire for a few weeks and still experimenting with options etc.

Iam shooting 4k @30fps and using as near as I can get to 60-100 shutter speed with the ND on (bright conditions)

I shoot PAL in a mov format using a LOG colour space.

Custom camera settings are sharpness 0 (-1 is way to soft imo) saturation -2 contrast -2.

Iam shooting over a rural area so lots of grass, trees, crops etc.
Iam also not flying at speed

When I get back from a flight and look at the films straight off the card they are as expected lacking in punch but show loads of detail and very little moiré
especially when flying over scrubby fields etc.

Iam then following Jims excellent advice on using Davinchi resolve to colour grade.

So far so good, but all the rendered files I then from resolve show terrible moiré and blocky artefacts in the mid tones.
Iam outputting in various formats and resolutions but still get the same thing.

Is this moiré and degrading of image due to downsizing the footage to say 1080 hd or am I missing a stage in post before exporting?

What is the workflow when downsizing 4k when rendering the final graded film?

Thanks guys!


2015-3-26
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Editart
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Sweden
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Hi Redeye

Unfortunately everything that you do with the footage will only give minor improvements or even make it worse. Noise reduction, adding slight amount of grain, unsharp mask, highpass filters or corrections of different sorts.There is no magic filter or noise reduction that can compensate for a low bitrate destroying the details. Basically thats what it is, the problem is the compression of the material. No matter how you adjust the sharpness, LOG or any other setting for that mater can make the footage look better.

I have 15 years of professional post work behind me with every format on the video market processed Ive been working with DV cameras back in the 90s struggling with not only hard DV compression but also low resolution. You cant simply add details that were never there to begin with. What annoys me is that this can easily be fixed by raising the bitrate in the recording.

My DLSR(EOS 1DX) camera delivers better image quality i 1080p with Intra Frame recording than the 4K image of the Inspire.

If you look at your footage, especially in the milky mid tones you can see a stuttering effect, like stop motion almost. Thats the GOP temporal compression(delta frames). Its really ugly and destroys the quality of both details and precieved quality.

This is why I cant use the Inspire1 for professional work, yet. And its just a waste of hardware.

DJI! Fix this please. Its not my first post regarding this and Im baffled that your R&D dep. let this pass. You better get someone that knows video quality into the R&D team before just releasing such an awesome Quad without letting it be the great tool that it can be.

Redeye, If you are working on a Mac computer, use Apple Prores422 or HQ as your intermediate and render format. Then you can go to H264 for delivery.

DJI - Wish list for video recording settings!!
Higher and Constant Bitrate (at least the double amount)
Intra frame recording



Thanks
Mike




2015-3-26
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Redeye
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United Kingdom
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Thanks Mike for your detailed answer, as you say its a shame the camera lets the inspire down a little/lot.
Although some of the footage I have seen on Vimeo, youtube etc shows little of the problems Iam getting which made me wonder if my work flow was to blame.

Most of the footage I will be shooting in the future will be for web sites etc so Cinema film quality is not needed. Am I better off just shooting the raw files in 1080 hd or will get the same problem?

My background is stills photography so "moving" images is a whole new discipline for me, Iam enjoying the learning curve but am a bit stuck on as I said output quality.

thanks again.
2015-3-26
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jimhare
Second Officer
Flight distance : 239035 ft
Australia
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Hi Redeye.  Can you please post a short clip that shows the problem at its worst?  If possible, uoload the original Inspire clip as well as a file (not YouTube.)

I generally don't see moire issues but sometimes see terrible compression scenarios where the image is littered with noise.

We just need to be clear which issue we're talking about.

As you say, and we've all discovered, Inspire footage can be a bit hit and miss, with the hits looking astounding and the misses looking horrible.

The Inspire is in no way alone in this.  When the 5DmkII DSLR came out, everyone made the mistke of thinking they could replace high end cinema cameras with it, but the line skipping, heavy h.264 compression and other issues meant if you didn't give it ideal conditions it was unusable.  

So testing and experience will give you the knowledge of which scenarios will show the Inspire at its best.
2015-3-26
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Redeye
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Thanks Jim, I will try and get some files uploaded over the next few days.
2015-3-26
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Editart
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Sweden
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Redeye, It sound like you might have higher quality demands than you think. You have noticed the lack of quality in the footage and now there is no going back. You say you don't need "Cinema Film" quality, why not? Who doesn't want" Cinema Film" quality? The better quality we can get out of the hardware, Im thankfull for! I believe that this hardware is more than capable of producing an image that is close to "cinema quality",what that now means? In this case, a clean image without noticeable artifacs or moire in the native footage might pass as cinema quality footage? The resolution is there, the sharpness need some tweaking, though I believe that the shaprness issues is very much connected to the compression artifacts.
Im sorry to say that the 1080p mode is possibly worse off, even lower bitrate and downsampling. Better to record in 4K and scale down the footage. Im an AfterEffects fan and have not much experience in Resolve to do post workflow. My experience is that it looks better to scale the footage from 4K to 1080p than shooting 1080p in the camera itself.

Moire effects is always a problem, more or less with every camera out there. I own both a BMCC and a BMPC camera and they both suffer from moire more or less. Its something that we need to know howto handle by knowing the limits of the hardware.

The LOG setting in the Inspire1 is great, but until they fix the bitrate issue the LOG mode will only produce even more terrible footage since the compression algorithm evens out similar colors and weak patterns, thats why milky midtones suffer so much in the compression. I would not recommend to use the LOG mode at this moment.
regards
Mike

2015-3-28
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Redeye
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United Kingdom
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Thanks Mike, I filmed some footage using the standard colour space at 4k 30fps, dialled down the saturation and contrast to -1 and have got to say I got some better footage, moving in the right direction now, thanks for your help
2015-3-28
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Editart
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Sweden
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Good to hear that you got some better results!
Sunny day today here in Stockholm, Sweden, ill might just give it another try with the standard color space

have a great day
Mike
2015-3-28
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Editart
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Im going to post something that might be considered slightly controversial here after all the discussions on sharpness settings. After some quick testing with +1 on the sharpness I looked at the footage. It seems like the compression is more evenly distributed within the frame. I guess this can have something to do with the added edge contrast that the sharpening filter has on the footage. Sure, it adds more moiré and flickering in details but it also keeps the compression in the midtones milder. However it is still far from OK. Also tried without the LOG picture setting and from what I could see the overall footage quality looked better than in LOG. LOG is great but need a higher bitrate to be useful in a postproduction workflow.

I would say that this camera has what it needs to create a clean and beautiful image. Its up to DJI if they will/can give us that with an updated firmware supporting higher bitrate and Intra frame recording. Ill keep repeating this until we get some sort of response from DJI


all the best

Mike
2015-3-28
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kelleyre
lvl.4
Flight distance : 59199 ft
United States
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I hope this all happens but I wouldn't  hold your breath

2015-3-28
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zeitlinger
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Italy
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Editart Posted at 2015-3-27 01:21
Hi Redeye

Unfortunately everything that you do with the footage will only give minor improvements o ...

Hi Editart, Hi Redeye,
I had the same problems since I need to use the footage professionally! "in the milky mid tones stuttering effect, like stop motion almost. Thats the GOP temporal compression(delta frames). Its really ugly and destroys the quality."
I showed my footage to the DJI guys, they told me to send the camera back to them - they will replace it.

In the meantime I shoot with the Inspire and a GoPro Configuration. This works fine! Can you tell me why the GoPro (which uses the same sensor and the same codec as the Inspire), gets better results on a big Cinema screen?
Thanks Peter, here the GoPro on the Inspire:

GoPro on Inspire1

GoPro on Inspire1
2015-3-30
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bornish
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United Arab Emirates
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zeitlinger@gmx. Posted at 2015-3-30 23:56
Hi Editart, Hi Redeye,
I had the same problems since I need to use the footage professionally! "in  ...

Is GoPro having the same sensor as the camera on the I1? Since when?
I actually thought that the Sony made camera coming with the I1 is an "unique" combo in terms of lens, 3x3 CCDs, internal correction algorithms before any compression and saving occurs. Would love to know more details about it, and truth be told I wonder why are we buying such expensive equipment without requesting FULL technical details? We need to start educating future generations about customer rights hoping that one day people would stop paying for what they don't need because they know they don't need it before buying it.
Sorry for shifting the topic a little bit.
Regards,
Bogdan
2015-3-31
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nquinn2
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United States
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zeitlinger@gmx. Posted at 2015-3-30 23:56
Hi Editart, Hi Redeye,
I had the same problems since I need to use the footage professionally! "in  ...

Zeitlinger,

Could you please tell me where you found a gimbal for the GoPro that will mount to the Inspire 1?  Also what additional equipment you need to get GoPro to send the  image to Pilot app.  I see an extra transmitter antenna hanging off the back in the photo.

Thanks for your help!
2015-4-3
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Editart
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Sweden
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zeitlinger@gmx. Posted at 2015-3-30 23:56
Hi Editart, Hi Redeye,
I had the same problems since I need to use the footage professionally! "in  ...

Zeitlinger,

I doubt that the replacement camera will generate any better results. Its just not that kind of problem that video cameras get when faulty. Compression problems/errors tend to be much more visual and colorfull If DJI says they need to replace the camera, Im getting scared, that means they do not know what they are looking at?

I still think its a hardware setting, its just not been optimised yet.

I noticed a few things trying different extreme ISO settings in daylight. The ISO setting is crucial, we know this already! But it afects the quality in ways other than just loads of noise at a high setting. Setting the ISO to 3200 is just devastating for most footage but in combination with a long GOP(8 frames) sequence in the H264 compression it gets really bad. You get what is called residual compression artefacts that stay between intra frames. Basically the noise freezes for 8 frames at a time, then updates when a new intra frame is encoded. Creating the stuttering effect in the footage. So this means that some of the footage actually has a lower, percieved framerate, than recorded. All of this is caused by the compresssion settings in the camera. The image from the camera without the H264 compression will probably look beautiful.

Its a shame DJI! And there is nothing that justifies this setting. Its just a bad call from DJI R&D and this needs to be changed ASAP. I have bought this great piece of equipment to be able to produce some high quality "professional" footage. Why did you build this thing if It cant generate proper H264 4K footage? There are plenty of "amateur" quads out there that produce OK HD footage at a cheaper price, why am I competing with them?

This is probably my 5th post regarding this, DJI is terribly silent on this topic!

regards
m







As a general advice and not new in any way. Keep the ISO at the lowest, always.
2015-4-3
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zeitlinger
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bornish@gmail.c Posted at 2015-3-31 17:15
Is GoPro having the same sensor as the camera on the I1? Since when?
I actually thought that the S ...

Bornish,

The footage from the GoPro4 looks more cinematic even from GoPro3+. There are no GOP "stop motion" effects like from the Sony Inspire camera with the same BitRate (60bpsec)
I can use the GoGPro for a big screen even in Cinema. The Inspire works well for Internet use. artefacts in the net are anyway present. Inspire footage endered out for TV or 2K cinema does not work yet. I am waiting for the camera upgrade, which will come for sure!
2015-4-3
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zeitlinger
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nquinn2 Posted at 2015-4-3 23:31
Zeitlinger,

Could you please tell me where you found a gimbal for the GoPro that will mount to th ...

1.) I am using a noname 3D gimbal from Hobby King or so (I´v bought a H3 3D DJI-Zenmusse, but that does not work without a NAZA2 or A1 flight controller - and DJI could not tell me how to connect it to the Inspire electronics)
2.) I attached the noname gimbal with cable straps to the Inspire gimbal mount very tight so the dumper from Inspire (which are very good) help me to reduce the jello effect.
3.)11.3V tiny battery which supplies a) the gimbal, b) the DX6ireceiver and c) the FPV video transmitter
4.) for pitch control I need to use a second RC control which I have from my previous flame wheel 550

Now I can use it for my professional areal work until DJI upgrades their Inspire - Sony Camera system
2015-4-3
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dbeck
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United States
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I don't get you guys.  Instead of talking about the I1 is not (and may never be) why don't you move up to one of DJIs bigger, more expensive rigs and put a Sony a7s on it?  You will never be happy with what the I1 IS as opposed to what you want it to BE.  If I truly needed 4K footage for a gig (I have not one client who has called for it) then thats what I would do.  For ME and for NOW what I'm getting from the Inspire 1 is great.  
2015-4-3
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zeitlinger
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dbeck@promobox. Posted at 2015-4-4 11:31
I don't get you guys.  Instead of talking about the I1 is not (and may never be) why don't you move  ...

I work with an EVO800 and Blackmagic at home. But travelling with batteries over 100Wh by plane is a hassle.,
thats why I use a flamewheel550 for professional filming internationally. I hoped to be well set up with the inspire but stop motion GOP artefacts prevent me from using the Sony-Inspire Cam professionally.
It would be easy to solve the problem. Just a new firmware for the Inspire camera would help! GoPro does not create GOP artefacts with the same bitrate and Ks!
2015-4-4
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Editart
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Sweden
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dbeck@promobox. Posted at 2015-4-4 11:31
I don't get you guys.  Instead of talking about the I1 is not (and may never be) why don't you move  ...

Well, don’t sign up Philip Bloom to promote the rig then, or? Is he just a fake cardboard figure promoting a fake product with fake specifications? Sorry but you just don’t see the point, and I cant blame you. I don’t want a bigger "better" quad! I want them to utilize whats already in there. Release the force for gods sake! Not limiting the equipment with some crappy settings in the compression, Its just terrible. I own a DJI Phantom2, a DJI RONIN and I am perfectly happy and have done great videos with both of them. But with the Inspire1 I’m not happy, why? Because DJI does not harness the potential of the quad they have developed and I demand more because I know there is more to it. Are you with me?

Its in its beta stage now, and DJI want us to help them finalize their "innovation". Well i think that’s great, I really do. But what I don’t like is being told by someone to go and get a better quad, when in my opinion, there is none. I don’t want a Spreading Wings S1000 quad that can carry my BMPC 4K camera and a follow focus, because I cant fly indoors with it. The Inspire1 is just about the best technology can create today. Just give us the quality it deserves to deliver. Before you answer this Mr.or Mrs.dbeck. Take a good look at your footage and really judge, is it the footage you would expect from a quad with this price tag? I know what my answer Is and I don’t blame you for answering different. We are just different people with different quality measurement standards.

regards
m
2015-4-4
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bakcheehong
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Malaysia
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I have this issue as well.  The footage seems stuttering. And I dont know how to solve it. It's going to be on big screen in cinema, hope someone can help me out.
2015-6-8
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zeitlinger
lvl.2
Germany
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bakcheehong Posted at 2015-6-8 17:20
I have this issue as well.  The footage seems stuttering. And I dont know how to solve it. It's goin ...

bachcheehong,

the only help is a propper exposure (ASA low and shutter around 1/50) - use the ND filter no much backlight, even photographically more beatitul, but the Inspire compression destroys any possibility to make corrections afterwards. Don't Underexpose - this brings the ,most visible artefacts!

If you have time let the camera check by DJI - I got mine replaced and it works fine now
2015-6-14
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