Need Help - Tons of motion blur on very minimal movement Red MX footage

[Alison Parker]

Hey guys, I shot a music video on Saturday on my Red MX and for the first time experienced a problem with motion blur.

There is NOT extensive motion.. I realize with a lot of big movements, blur is inevitable.. but even on my close up shots of the singers face, just him simply moving his head side to side goes blurry / smeary out of focus, whatever you want to call it.

I shot a bunch of stuff in 2k 48 frames, and that does not have the problem. However all of the 4K 24 fps footage, whether it is wide, medium or close up, has this motion blur problem.

I am told by my camera crew ( i was director ) that we used the exact same settings we always have in the past and they are stumped as to why this happened.

Any ideas as to what could have caused this, and secondly, if there's ANY way to fix it at all?

I've attached a picture example of a close up, just so you know it's minimal movement...when he's basically STILL, the picture is perfect.

 

[Marcus Struzina]

The problem looks like shutter angle/exposure time. Probably using 1/24 th at 24 frames or in other words a 360 degree shutter. When you switched to 48 frames of course the shutter speed would of been at least 1/48th of a sec.
Unfortunately no way to fix it that I know of.

 

[Eki Halkka]

The problem looks like shutter angle/exposure time. Probably using 1/24 th at 24 frames or in other words a 360 degree shutter. When you switched to 48 frames of course the shutter speed would of been at least 1/48th of a sec.
Unfortunately no way to fix it that I know of.

Might be - hard to say from a single frame. Could also be that there's nothing wrong with the footage, other than the asker noticing the motion blur (which is not an error) for the first time. The individual frames are NOT supposed to look sharp really...

 

[Alison Parker]

Might be - hard to say from a single frame. Could also be that there's nothing wrong with the footage, other than the asker noticing the motion blur (which is not an error) for the first time. The individual frames are NOT supposed to look sharp really...

Please check my thread on DVXUSER as well for more still grabs... it's not just in the stills, its very noticeable when watching the video..

http://www.dvxuser.com/V6/showthrea...movement-Red-MX-footage&p=2179693#post2179693

 

[Alison Parker]

Here is what I found on the camera report for that shot in particular that u see in the still frame:

Lens - 100
Stop - 4
No Dolly
Shutter - 1/48
ISO - 800
FPS - 24

Does this make any difference to your conclusions?

 

[Alexander Ibrahim]

I concur. It looks like excessive motion blur.

I have the same guess as everyone else here, the shutter was too open/slow, possible 360°.

If that's the case, you can try to sharpen in post... but I wouldn't hold out much hope. That's definitely a counsel of desperation. There are some other post tricks you can try, but that will probably lead to more expense that a reshoot with dubious results. Again, a counsel of desperation.

My only trouble is that 360° doesn't normally look that blurry if the subject is as still as claimed. Just for sanity I did a quick shot with a 7D at 1080/24p 1/30 shutter... far sharper than this image or the ones I see on DVXuser.

The subject was most likely moving faster than you thought.

There may be other contributing factors... for example if there is a post accumulate or motion blur added.

You should post the a portion of an r3d file that is exhibiting this problem, so that users here can see the problem in motion in original media.

I really think the problem is on set. Its prudent to eliminate all the other potential issues before making that determination.

If it does turn out to be an on set issue, then you should plan on a reshoot.

 

[Gunleik Groven]

From that single frame, it's not possible to judge anything, really...

It makes sense that the 2k has less motionblur, thoughif it was set at relative shutter...

 

[Alison Parker]

I concur. It looks like excessive motion blur.

I have the same guess as everyone else here, the shutter was too open/slow, possible 360°.

If that's the case, you can try to sharpen in post... but I wouldn't hold out much hope. That's definitely a counsel of desperation. There are some other post tricks you can try, but that will probably lead to more expense that a reshoot with dubious results. Again, a counsel of desperation.

My only trouble is that 360° doesn't normally look that blurry if the subject is as still as claimed. Just for sanity I did a quick shot with a 7D at 1080/24p 1/30 shutter... far sharper than this image or the ones I see on DVXuser.

The subject was most likely moving faster than you thought.

There may be other contributing factors... for example if there is a post accumulate or motion blur added.

You should post the a portion of an r3d file that is exhibiting this problem, so that users here can see the problem in motion in original media.

I really think the problem is on set. Its prudent to eliminate all the other potential issues before making that determination.

If it does turn out to be an on set issue, then you should plan on a reshoot.

ok, seeing the video for yourself is a good idea, but how do i post an r3d file? i can upload a portion of a clip i've log and transfered to apple pro res 422 hq, is that okay? to youtube?

 

[Alexander Ibrahim]

Here is what I found on the camera report for that shot in particular that u see in the still frame:

Lens - 100
Stop - 4
No Dolly
Shutter - 1/48
ISO - 800
FPS - 24

Does this make any difference to your conclusions?

Not really.

Camera reports can be mistaken.

That report doesn't jive with your claim that there was a lot of light in the scene. That exposure would call for 24 candles of light, which is about what a computer monitor displaying a white screen puts out at 8 inches

Post the r3d.

 

[Alison Parker]

Not really.

Camera reports can be mistaken.

That report doesn't jive with your claim that there was a lot of light in the scene. That exposure would call for 24 candles of light, which is about what a computer monitor displaying a white screen puts out at 8 inches

Post the r3d.

for sure I will post the r3d file but how do i do it?

 

[Eki Halkka]

Here is what I found on the camera report for that shot in particular that u see in the still frame:

Lens - 100
Stop - 4
No Dolly
Shutter - 1/48
ISO - 800
FPS - 24

Does this make any difference to your conclusions?

To me this sounds like there's the normal, default amount of motion bur, and pretty normal amount of light for an interior / studio shoot with an MX:ed Red1. Assuming the report is correct.

If you can post two consecutive frames, we can determine / verify the amount of motion blur pretty easily.

 

[Eki Halkka]

That exposure would call for 24 candles of light, which is about what a computer monitor displaying a white screen puts out at 8 inches

Doesn't sound right to me at all...

 

[Alexander Ibrahim]

for sure I will post the r3d file but how do i do it?

You know... it occurs to me I've never posted an r3d here.

Transcoding to ProRes, or anything really, will obscure the data we are after to do diagnosis.

I guess what I'd do is find a short clip (8 seconds or less if you can) with the problem and post it to dropbox or some other filesharing service, then post a link to it here.

I am way past my bedtime... so hopefully the community will take over and have a look.

 

[Alison Parker]

i need to crash too but will try that in the morning, thanks guys, i'll be back at it when i wake up for sure

 

[PerroneFord]

Doesn't sound right to me at all...

Maybe this will assist:

http://www.panavision.co.nz/main/kbase/reference/tbleExposure.asp

Alexander's numbers coincide with my calculations, and the Panavision chart as well.

~25FC is a pretty dim set.

 

[Shawn Seifert]

Hey Guys,

I was the 1st AC on this project and I know for a fact the shutter speed was at 1/48th of a second in normal mode. I reset it several times, especially after moving the camera in and out of varispeed. Also did several restarts of the camera throughout the day, so it wasn't just a small glitch needing a reboot.

I wasn't noticing any issues with excessive motion blur on my monitor, but the director was seeing something on set with her monitor. We pulled footage off the hard drive and opened it in Red-CineX and took a look and all looked normal to all of us (Director, DP/CAM Op, and Me). Just in case something was wrong, we shot some footage a 1/96th of a second, which seemed to make the footage sharper on the directors monitor, but still has this motion blur problem in post.

We'll post a small r3d tomorrow and see what you all think.

 

[Marcus Struzina]

Eki's idea of the 2 consecutive frames is the best idea to get to the bottom of this.

 

[ericyoung]

You can look at the clip metadata in Redcine-X to confirm the shutter settings.

 

[PerroneFord]

Shawn, can you confirm the lens apeture, filtration, and light levels on set?

 

[Alexander Ibrahim]

Doesn't sound right to me at all...

Eki, are you responding to me or to the camera log?

I just plugged the ISO and lens settings into Toland to get the footcandles for exposure, then used my Sekonics in incident mode on my Gateway (which happens to be displaying almost 100% white) monitor to find the distance where the reading was 24fc.

Since you said it didn't look right I checked the ASC manual... which calls for 25fc at ISO 800 24fps 180° t/4.

I also metered for exposure with the Sekonics. Its set to 172.8° right now, and gave me f/4 at just under 9 inches from the monitor.

OK, so that was my experimental method.

My point is that ISO 800 doesn't really need a lot of light, and that exposure is correct for what is actually a pretty dim set.

So, that's why I infer that the log may be incorrect.

I should restate- either the log is incorrect, or Alison's assessment of the light level was inaccurate.

This diagnostic process makes the assumption that a unique problem with the RED camera is less likely than human error.

I don't mean that to be a put down... we've all screwed something up once in a while.

So Shawn, I assume you stand by the camera log. Do you agree that there was a lot of light on set? How would you characterize the subject's motion on set?

If we can all be certain that there was no on set error, then you may have a unique issue... and you should contact your RED representative & open a support ticket. (In fact I'd open a support ticket in any case right awa if you haven't already, and link this thread in your report.)

OK... to bed for real, its almost 4am for me.