Mavo LF : banding / distorted footage

This topic contains 28 replies, has 5 voices, and was last updated by  Gualbert 1 month ago.

Viewing 15 posts - 1 through 15 (of 29 total)
  • #5399

    Steven
    Participant

    So, I own a Mavo LF since a few months now. I’ve been searching for some info on this matter for a few weeks but I can’t find anyone who had the same experience. Most of the time the footage is great & I love working with the Mavo LF. But there have been a few times that we noticed a big problem. I’ve included these 2 screenshots to show you what happened. (this is from some corporate event but it has happend before while shooting a short film, I can Include screenshots of that one to if needed).

    As you can see, severe ‘banding’ occurs in the background. Does anyone know why this happens ? Can I prevent this from happening in the future ? (it gets worse ofc when grading, so the footage is nearly unusable). Or do I have a broken camera / sensor / … .

    I’ve send an email to kinefinity europe but have not got any reply. In 3 weeks I’m traveling to the other side of the world for a big job, so I need to be sure that I can rely on my Mavo LF.

    #5401

    raafi
    Moderator

    Hi Steven. I’m sorry this is happening. I haven’t experienced this. Can you provide a little more info about what codec you’re shooting/editing in?

    #5402

    Steven
    Participant

    This was shot in ProRes 422 Full HD, I just checked the raw footage on another computer (to exclude the fact that it has something to do with the computer or software) but you can clearly see it on the raw footage on this one to (not imported in premiere or final cut).

    Another thing i’ve noticed … the footage is always presented in a folder with the audio files seperate (wav) + some other stuff. One of those is a ‘snapshot’, bmp file … it appears to be the 1st frame of the shot. This image is very clear, the shadows are soft as they suppose to be & the banding does not occur. Actually it looks like how the footage should have looked.

    So why is this happening ? Could my sensor have a bug ? If this is a common problem, someone else must have experienced it, no ?

    I’ll make a screenshot of the short film scene we shot, that one was shot at 4K, ProRes HQ & has the same ‘distortion’ on several shots.  … TBC

    #5403

    Steven
    Participant

    Here are 2 short videos I did when I just received the camera, using a 50 mm Canon EF 1.2 (I was just recovering from a surgery so all is filmed straight out of bed at my parents house)

    Password = azerty (both)

    https://vimeo.com/333442159  *you can clearly see it in the 1st shot on the ceiling.

    https://vimeo.com/333448611 *I tested the Mavo’s low light performance in this one, awesome btw, but again it starts appearing i some shots (the close up of the ‘hard camera case’ … on the left side in the brown shadows. I graded this in an extreme way to see how the footage would react, yes indeed it looks awful with those colors screaming at you 🙂

    … more screenshots on the way.

    #5407

    Gualbert
    Moderator

    never seen this banding in footage… I’ve seen it on the Monitor but that’s expected… Instead of screenshots, do you have a 3 seconds ungraded clip direct for the cam? No processing and no grading? Also if possible the whole folder with .mt and the slate file…

    #5408

    Steven
    Participant

    yeah I could but the last corporate shoot files are too big, it’s about 20 mins each shot (speakers event). Maybe I can find some of those 1st test shots on a hard drive somewhere. But if you need this to confirm that this happend while processing, I must disappoint you. The banding is already present in the unprocessed footage.

    You can see it on the 1st vimeo link in the 1st (non graded) shot, yeah it’s been compressed by vimeo & adobe, but you need to trust me the banding was already there. I’m not going to waste my time on this forum just for the fun of it. I really need some closure on this matter. If nobody has ever experienced this, my Mavo LF sensor might be bugged … I have a big job ahead so I’m a bit stressed out.

    Thx anyway !

     

    #5409

    Steven
    Participant

    Ok, I uploaded a complete Mavo LF footage folder to Dropbox (link below).  16sec of footage while setting up the camera when rehearsal was going on. This shot was filmed at 4K, when I started shooting after, I changed it to HD. Anyways banding is the same at 4K, take a close look at the left corner … the banding gets worse (more noticeable) closer to the end of the shot.

    Here it is: https://www.dropbox.com/sh/ps9qmpf7bnbiz7q/AAALvRfMBX98ae9APduIcAXXa?dl=0

    Any help is appreciated 🙏

    #5412

    Steven
    Participant

    I’m closing down on it … I’ve found this article, nothing but love about the Mavo LF but at the end he touches my concern.

    “It hasn’t been all roses since using the Mavo. I realized after this shoot that something wasn’t exactly right with it in the low light. I experienced a little bit too much FPN in the shadows. After consulting with my dealer, they took care of it and got it calibrated and sent back to me very quickly. Now I don’t have any issues with the FPN, and it was nice to experience a professional and fast after-sales service from Kinefinity Amersterdam, A+.”

    FPN = FIXED PATERN NOISE (I guess this is exactly what is happening to my footage)

    READ THE FULL ARTICLE HERE https://ymcinema.com/2019/07/16/kinefinity-mavo-lf-filmmaking-tips-for-ideal-execution/

    I think I need to get in touch with Kinefinity Europe, amen.

    #5414

    Gualbert
    Moderator

    Just downloaded your clip…. this is insane!!! Even your BMP snap is plagued with that banding. I’m not sure your article is related, banding and FPN are not the same issue. Also, not sure why you decided to decrease your HS whilst shooting at such low ISO for that indoors shot. Not that it matters. I’ll try tomorrow to replicate your settings and see if I can duplicate your issue, kinda late now here in Asia. Cheers!

    #5415

    Steven
    Participant

    Yeah true at 1st I didn’t notice it in the BMP, but it’s all over the place. This might sound stupid but what is HS ?

    Thx for reaching out !

    I’ve also contacted Kinefinity Europe, hopefully someone can figure out how to fix this asap.

    #5417

    Gualbert
    Moderator

    Was able to duplicate the issue… No idea what it is, just know that after Kine Neutral LUT and some minor tweaks in Davinci the impact gets minimized. Also noticed that in FF if you go to 6K (no down sampling) it is almost unnoticeable. Also noticed that if you ETTL the banding goes away completely, maybe Mavo LF can’t handle ETTR at all? Just to let you know I was a few KineOS version behind you so updated to the latest and greatest, did a black balance and factory reset and that won’t make it go away. I would suggest if you have a big job coming soon to try ETTL and. if your storage and computer can afford it, to shoot in 6K. Sorry I wasn’t able to help but I am just a user like you, hopefully Kine will explain what that banding is and how to deal with it. Cheers!

    P.S. HS is highlight setting, you go to configuration then shooting then Highlight setting, the default is 4.3 which Kine says is the sweet spot to preserve the maximum DR in ISO mode. Thanks for participating in our KineCommunity forum and for giving us the opportunity to share knowledge between Kine Users. It is always appreciated!

    #5418

    Steven
    Participant

    Thanks Gualbert ! I tried what you said but the results are rather disappointing. The good thing is, I’m closing in on the problem & I figured out what triggers the banding.

    So I did what you told & put him to 6K FF. Then I ran some tests with my Sigma art 50mm 1.4 … (also set the HS to 4.3, thanks for the tip). The banding was still there, nothing changed. I played with my exposure as you said & tried ETTL + ETTR, still the same only when slightly overexposed the banding got clipped in the highlights.

    The I started testing at different lens aperture settings. Now it all became clear, when opening the aperture to 1.4 the banding was at it’s worst. All shallow parts in the image became big circular banded areas. As I shifted slowly step by step, closing the aperture it disappeared.  I’ve recorded every aperture setting for 3 secs. I’m gonna study the footage more thoroughly on a decent monitor but as I went past 2.5 it was gone. So it seems my Mavo can’t handle shallow DOF. The sharp part of the image is crisp as it should be, but everything else is banded at 1.4 !

    Another thing that can be confirmed: it’s not my lens. So far I experienced the exact same issue with 3 different lenses. The Sigma art 50mm 1.4, Canon 24-70 2.0 & a set of rented Xeen primes. Always when shooting with open aperture settings.

    Kinefinity Europe reached out so they are looking into it atm. I’m a big fan of shallow DOF, especially for fictional work + combined to a FF sensor it should bring nice cinematic images. So I’m still wondering if this issue is a bug in my camera or every Mavo LF has this problem.

    I’ll upload the testing footage with step by step aperture settings to dropbox asap, so you can see what happens !

    TBC

    BTW: I bought a 1TB Sandisk Ultra 3D SSD, it works like a charm & fits perfectly. Good to have a backup when the Kinemag runs out of space. It only costs about 150$.

    • This reply was modified 1 month ago by  Steven.
    #5420

    Gualbert
    Moderator

    Morning Steven! Are you completely sure you still saw banding in 6K? I just re-did my test and when switching between 3K oversampling and 6K I can see banding in oversampled 3K but none in 6K. Was also able to see banding in 4K as well but less noticeable. My guess this banding may be the result of their oversampling code, maybe the way it deals with non-textured or flat spaces or surfaces (which would also explain why portion out of focus like shallow DoF are affected). If it is not much to ask perform the following: set a frame where you can nail the banding pattern and without changing anything else switch to 6K and see the effect.

    #5422

    Steven
    Participant

    Hi Gaulbert, I think you’re right. I jumped into conclusions too fast based on what I saw happening on my Kinemon. I need to study to footage on a decent monitor but it seems to be gone at 6K. I’ve uploaded 2 shots, 1 underexposed & a brighter one.

    Kinefinity Europe also asked me to install some new firmware & do another test at 4K … TBC

    6K testhots https://www.dropbox.com/sh/jvksgf0vra9ga5r/AABmjWKo7dT9HZOksstkLkA9a?dl=0

    #5424

    Martin Friedrich
    Participant

    Hi Steven and Gualbert,

    I don’t own a Mavo yet but I am really close to placing an order.

    So first thanks for sharing your findings and the footage, it is rather concerning, as shooting oversampled 4K is what I woud do a lot as well.

    I looked at your files in Davinci Resolve on my HD grading monitor and on an UHD OLED, the banding in your UHD footage is very visable on the UHD set and gets even worse when further downsized to HD on my grading monitor. (both screens are connected to a Blackmagic videocard btw, so no funny GPU stuff going on here as well).

    Even in the 6K footage of the cupboard the banding is visible, in both shots. I can even “read” it in the waveforms, which are to jaggy for such a smoothe gradiant. It gets better though when the lut is applied, but it shouldn’t be  there in the first place I think.

    Hope you or Kinefinity can resolve this issue!

    Martin

     

    PS: maybe ISO 160 and Highlightstops at 3.6 are making things worse as well? Although I guess you had different settings for the clip on vimeo?

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