Weird Noise Pattern on Overcrank/Slow Motion Shots. RAW R3D File Inside.

[Corey Benoit]

So when shooting 4k WS @ 71fps I have the shutter set to 1/144. I also notice the compression is 13:1. I did this at a few weddings for some nice slow motion and noticed a little bit of noise that looked like h.264. However it was dark. What really has me confused is that I have the same patter in my footage I shot today at a park in broad daylight. So bright I had to use a variable ND filter, and stop the lens to f/4. Just to prevent highlight clipping.

The file is below. Its a full clip in 4k WS. Any help is greatly appreciated!


http://www.faymusmedia.com/slow_71.R3D

 

[Paul Russell]

I'm guessing you're a stills photographer turned video guy.

You need to set your shutter speed to 'relative', and then 180 degrees. This is 1/2th of the frame rate, so 24fps will give you 1/48th shutter. 100fps will automatically give you a 1/200th shutter. This is how everyone shoots, with a few exceptions.

Regarding your noise, did you do a blackshade at that shutter speed or thereabouts?

 

[Corey Benoit]

I'm guessing you're a stills photographer turned video guy.

You need to set your shutter speed to 'relative', and then 180 degrees. This is 1/2th of the frame rate, so 24fps will give you 1/48th shutter. 100fps will automatically give you a 1/200th shutter. This is how everyone shoots, with a few exceptions.

Regarding your noise, did you do a blackshade at that shutter speed or thereabouts?

I understand video well. I didn't turn to video from photo, been doing them both a very long time and I did black shade for that speed. The fps are 71.93 I believe, which is why I set it to 1/144 shutter.

 

[Paul Russell]

The leaves and trees are killers for compression, and I think that's where your noise is coming from. The algos get confused with so much micro detail and it all goes noisy. I've seen similar results myself on the MX sensor back in the pre-Dragon day.

But if you run it through RCX with denoise at 6 it's not too bad. I'd try transcoding through RCX first (to either ProRess 422Hd or Cineform depending on your platform) and then a light touch of Neat Video on your final output should get you in to an acceptable position that the client will like.

Here's your clip in 1080p ProRes through RCX at Denoise 6.
https://www.amazon.com/clouddrive/s...cw7Gk77nvI7ZyG7T16rXW?ref_=cd_share_link_copy

 

[Corey Benoit]

The leaves and trees are killers for compression, and I think that's where your noise is coming from. The algos get confused with so much micro detail and it all goes noisy. I've seen similar results myself on the MX sensor back in the pre-Dragon day.

But if you run it through RCX with denoise at 6 it's not too bad. I'd try transcoding through RCX first (to either ProRess 422Hd or Cineform depending on your platform) and then a light touch of Neat Video on your final output should get you in to an acceptable position that the client will like.

Here's your clip in 1080p ProRes through RCX at Denoise 6.
https://www.amazon.com/clouddrive/s...cw7Gk77nvI7ZyG7T16rXW?ref_=cd_share_link_copy

Thanks for touching up my sample, I appreciate your time. I will watch it once I get home from this event. I just wanted to mention the noise was on the skin and clothes mostly too. I did slow motion of water and it was clean.

what causes the noise on the skin and clothes? Is 13:1 too high? Pirates of the Caribbean was filmed at 13:1 I heard.

 

[Anthony Berenato Jr]

I got a chance to view your clip and here were some of my thoughts at first glance:

- The 4K crop on the Dragon sensor is going to make the digital grain feel a lot more pronounced (as you're looking closer into a portion of the grain that's compacted into a much less revealing full-sensor image). If there's enough light available, a lower ISO would have hidden a lot more of the sensor's grain. (Side note: It does change the balance of dynamic range in the camera, but it may have fit well with your composition's even light with cleaner shadows. Phil has great charts on this.) The 800 ISO Dragon look has a bit of tasteful organic grain, but it's not everyone's cup of tea. I do find that at 6K - I think it looks gorgeous.

- As Paul mentioned, a lower compression rate would have cleaned up some of the grain in the highly detailed image. A much shallower depth of field may have also helped the algorithm to decipher what information can be broken into more artifacts. High compression and high detail don't seem to go hand-in-hand. The lower the better when heavy textures, lots of trees, foliage are in-focus.

- As Paul also mentioned, your shutter angle is 190 degrees. It seems like your frame rate was actually switched to 76 by accident - though this shouldn't change the look too much. My question here is if you calibrated your sensor / performed a blackshade for your 1/144 shutter. If the sensor wasn't calibrated correctly, that would also add a bit of grain to the image.

This was always a tough scenario for me when I had my Scarlet Dragon, especially when I shot slow-motion in the woods a few times. Based on the limitations of the camera, I could never tell if it was better to film at 5K at 48 with a higher compression ratio, or 4K with either higher FPS or lower compression. Most of the time, the image was sharper and cleaner when siding with the higher resolution (because of less crop / smaller grain structure) - as long as the slow motion timing was acceptable to the director. It also took me a long time to decide on my flavor of ISO and learn how ISO affects the dynamic range of the sensor. My favorite spot is almost consistently 500 ISO, just my personal taste for the image aesthetics.

Anyway, sorry for all the information. In terms of what you can do now, it seems like the image cleans up a bit when you start bringing the shadows back down. I had your image at 640 ISO w/ -0.249 Shadow + 5543 Kelvin. You can always denoise from inside the RED software, but I believe it only affects the blue-channel if I remember correctly. A go-to program like NeatVideo will probably clean up just nicely after a few minutes of working with the footage. There's always so much to learn in the way the camera works and interacts with different environments and settings.

 

[Corey Benoit]

I got a chance to view your clip and here were some of my thoughts at first glance:

- The 4K crop on the Dragon sensor is going to make the digital grain feel a lot more pronounced (as you're looking closer into a portion of the grain that's compacted into a much less revealing full-sensor image). If there's enough light available, a lower ISO would have hidden a lot more of the sensor's grain. (Side note: It does change the balance of dynamic range in the camera, but it may have fit well with your composition's even light with cleaner shadows. Phil has great charts on this.) The 800 ISO Dragon look has a bit of tasteful organic grain, but it's not everyone's cup of tea. I do find that at 6K - I think it looks gorgeous.

- As Paul mentioned, a lower compression rate would have cleaned up some of the grain in the highly detailed image. A much shallower depth of field may have also helped the algorithm to decipher what information can be broken into more artifacts. High compression and high detail don't seem to go hand-in-hand. The lower the better when heavy textures, lots of trees, foliage are in-focus.

- As Paul also mentioned, your shutter angle is 190 degrees. It seems like your frame rate was actually switched to 76 by accident - though this shouldn't change the look too much. My question here is if you calibrated your sensor / performed a blackshade for your 1/144 shutter. If the sensor wasn't calibrated correctly, that would also add a bit of grain to the image.

This was always a tough scenario for me when I had my Scarlet Dragon, especially when I shot slow-motion in the woods a few times. Based on the limitations of the camera, I could never tell if it was better to film at 5K at 48 with a higher compression ratio, or 4K with either higher FPS or lower compression. Most of the time, the image was sharper and cleaner when siding with the higher resolution (because of less crop / smaller grain structure) - as long as the slow motion timing was acceptable to the director. It also took me a long time to decide on my flavor of ISO and learn how ISO affects the dynamic range of the sensor. My favorite spot is almost consistently 500 ISO, just my personal taste for the image aesthetics.

Anyway, sorry for all the information. In terms of what you can do now, it seems like the image cleans up a bit when you start bringing the shadows back down. I had your image at 640 ISO w/ -0.249 Shadow + 5543 Kelvin. You can always denoise from inside the RED software, but I believe it only affects the blue-channel if I remember correctly. A go-to program like NeatVideo will probably clean up just nicely after a few minutes of working with the footage. There's always so much to learn in the way the camera works and interacts with different environments and settings.

Thanks for all the info! I noticed even with a 4k WS crop there is only this type of noise when shooting slow motion. I did some clips in 4k WS @ ISO 800 and exposed decently has nowhere near the noise of this clip.

i am currently saving for a epic upgrade. Then will be selling my scarlwt as I do a lot of slow motion, I would love to be able to shoot 60p in 6k/5k @ 4:1 or 5:1 compression.

 

[Scot Yount]

Ain't you a kinda famous (FAYMUS) BlackMagic totin' RED disser?

KIDDING of course....:001_tt2::001_tt2::001_tt2:

 

[Corey Benoit]

Ain't you a kinda famous (FAYMUS) BlackMagic totin' RED disser?

KIDDING of course....:001_tt2::001_tt2::001_tt2:

Hey Scot. Haha yea. Hopefully I didn't come off disrespectfully, I wasn't dissing red. In Fact I love the time that I had with the red scarlet MX, so I ended up buying the scarlet Dragon and adding it to my arsenal LOL. I just try to tell the truth about the gear and how it is without offending anyone if possible. Just telling truth about features.

I was at a black magic convention two weeks ago and I was filming everything on my red LOL

 

[Scot Yount]

Hey Scot. Haha yea. Hopefully I didn't come off disrespectfully, I wasn't dissing red. In Fact I love the time that I had with the red scarlet MX, so I ended up buying the scarlet Dragon and adding it to my arsenal LOL. I just try to tell the truth about the gear and how it is without offending anyone if possible. Just telling truth about features.

I was at a black magic convention two weeks ago and I was filming everything on my red LOL

That's pretty funny actually. I remember when I saw the review I think one of the issues was sharpness. I now know (and didn't know then) that RED performs no in camera sharpening and the BlackMagic cameras do. I wasn't offended and anyone who was needs to lighten up. I learn a lot from discussions like the one you have started here. When I first looked at your clip, I initially thought your problem was in fact diffraction. Then I saw you shot at F4, so that wouldn't be the problem!

 

[Corey Benoit]

That's pretty funny actually. I remember when I saw the review I think one of the issues was sharpness. I now know (and didn't know then) that RED performs no in camera sharpening and the BlackMagic cameras do. I wasn't offended and anyone who was needs to lighten up. I learn a lot from discussions like the one you have started here. When I first looked at your clip, I initially thought your problem was in fact diffraction. Then I saw you shot at F4, so that wouldn't be the problem!

Yea red doesn't perform any in camera sharpening. The blackmagic cameras may perform a slight amount however the guys at blackmagic have never confirmed that to me. The RED MX Scarlet was great, it was just not quite to the run and gun standards of the black magic as far as ease of use. The quality of the MX was great tho. The dragon is killing it.

 

[Eric Santiago]

Haha no one told me that you cant use the Scarlet/EPIC as run and gun

Ive ran my baby to all kinds of fast paced shooting.

God even a wedding.

All you need is a lot of SSDs, BRICKs/VOLTS and a kick ass intern

 

[Nick Gardner]

This is 1/2th of the frame rate, so 24fps will give you 1/48th shutter. 100fps will automatically give you a 1/200th shutter. This is how everyone shoots, with a few exceptions.

While that was true mostly for shooting film, when you couldn't open the shutter past 180 degrees, when shooting digital, anything over saw 60fps, it is quite common to use a 360 degree shutter for the light savings. Once you get over 100fps, and your shutter speed is less than 1/100th of a second this is even more true. Yes if you are shooting sports or extreme action hipster douchbaggery or whatever the hell, you will get some motion blur. Use a skinnier shutter when shooting high action/hipster/tightropwalking/fire drinking/ball gargling.

I shoot a lot of slowmo, and have for a long time, from back in the days when you needed special highspeed film cameras, to dragon, to phantom. Don't be afraid to open the shutter. The faster you go even moreso.

Nick

 

[Andy White]

extreme action hipster douchbaggery

LOL, it finally has a name... now all the vids with beardy dudes, water bombs & extreme flicker playback can have their own sub-genre :thumbsup:

 

[Mike P.]

That's pretty funny actually. I remember when I saw the review I think one of the issues was sharpness. I now know (and didn't know then) that RED performs no in camera sharpening and the BlackMagic cameras do. I wasn't offended and anyone who was needs to lighten up. I learn a lot from discussions like the one you have started here. When I first looked at your clip, I initially thought your problem was in fact diffraction. Then I saw you shot at F4, so that wouldn't be the problem!

Actually, I haven't read anything saying that BM does do any in-camera sharpening. That said, it does NOT have an OLPF, so that makes BM images substantially sharper (pixel-for-pixel) compared to any camera that has an OLPF... In my experience, 4k BM is sharper looking than 5k MX, even with post sharpening. HOWEVER, no OLPF also means artifacts like moire and aliasing are *far* more likely.

Haven't looked at the file yet, but did you black shade at the higher shutter speed (I know Dragon is kind of BS sensitive compared to MX).

 

[Robino_J]

This happened to me as well when shooting in a forrest once using EPIC MX. The codec just can't take it a lower compression ratios. Also happened while shooting the sea from up above - the waves detail was too much even at 5:1, the shadow side of rocks in that shot were falling apart.