Terrible Noise Shooting 4K L-Log

[Roddy]

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I'm seeing terrible noise running across my image shooting L-Log in 4K. HDMI out into PixE7 which is set to ProRes 422HQ 10bit. I tried 422 (nonHQ) and the same result. The image cleans up fine when L-Log is set off. Anyone?

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[tpf1952]

I'm seeing terrible noise running across my image shooting L-Log in 4K. HDMI out into PixE7 which is set to ProRes 422HQ 10bit. I tried 422 (nonHQ) and the same result. The image cleans up fine when L-Log is set off. Anyone?

 

 

I love my SL(s), but high ISO performance in video is a weakness. I make my living shooting stills and video, relying on Leica gear for stills, but other brands (Sony) for video. From the HDMI output of the Sony A7RII and SII, I record to a Pix E5, recording Slog 2 to ProRes 422, at 8-bit, the only option with Sony. I'm fixated on log; I only shoot REC 709 if a client is doing the post production. Regardless whether you record L-Log internally or externally, shooting with the SL at ISO 800 is for me, the absolute upper limit; 1600 is simply out of the question.

 

As an example, record the same scene on the SL, say for example, an interior interview lit with a combination of filtered LED lights and ambient. Assume that this environment includes some shadow areas in the background or on the side of the face opposite the key light. When you play back the media recorded internally, the SL produces blotchy, mushy "details" in the shadows. This is the result of internal noise reduction in the SL. Now play the same scene recorded on your Pix E7. The HMDI signal bypasses the SL's noise reduction, but renders noise in all it's ugliness. It is, to say the least, distracting.

 

When I'm shooting interviews on location, I almost always need high ISO capability. I can't carry enough gear "on the road" to re-light an entire space, thus my strategy of balancing ambient with portable lights. In some instances, ISO 400 can work, but that doesn't occur often enough to make the SL my "go-to" production camera in the field.

 

I wish it weren't so. I would prefer to work with the SL and to color correct footage acquired in 10-bit. But noise is noise.

 

Tom

[peggers]

Hello.

 

I’ve been playing around quite a bit with the video on the SL. First some caveats - I am NO expert, having come across from years of M use. And secondly I’ve been recording in HD not 4k. But here’s what I’ve learnt.

 

I also saw terrible noise when shooting in vlog. But after some reading i found that I needed to over expose by around 1 stop, or maximise ‘expose to the right’. Then the noise just goes. I’ve shot at 3200ISO and was amazed by the results.

 

Now working this way you can’t just use a Sony or Arri LUT in post, which require ~2 stops under exposure from what I have read. I used a curve adjustment in latest version of FCP X to correct the exposure (inverted log curve in shape), plus a substantial lift of saturation. I’m not there yet in terms of look, but grain has gone. I am planning to make my own LUT to give a good starting point to grade from - i.e detail in shadows and highlights with nicely distributed mid tones.

 

I’d be interested to know what others find works well. I wish Leica would produce a LUT we could all use, or at least give us some more guidance - as I’ve got a suspicion it would unlock this camera’s video capabilities for many of us, and burnish their film making credentials for them.

 

Happy creating!

 

 

Sent from my iPhone using Tapatalk

Edited January 22, 2018 by peggers

[tpf1952]

Hello.

 

I’ve been playing around quite a bit with the video on the SL. First some caveats - I am NO expert, having come across from years of M use. And secondly I’ve been recording in HD not 4k. But here’s what I’ve learnt.

 

I also saw terrible noise when shooting in vlog. But after some reading i found that I needed to over expose by around 1 stop, or maximise ‘expose to the right’. Then the noise just goes. I’ve shot at 3200ISO and was amazed by the results.

 

Now working this way you can’t just use a Sony or Arri LUT in post, which require ~2 stops under exposure from what I have read. I used a curve adjustment in latest version of FCP X to correct the exposure (inverted log curve in shape), plus a substantial lift of saturation. I’m not there yet in terms of look, but grain has gone. I am planning to make my own LUT to give a good starting point to grade from - i.e detail in shadows and highlights with nicely distributed mid tones.

 

I’d be interested to know what others find works well. I wish Leica would produce a LUT we could all use, or at least give us some more guidance - as I’ve got a suspicion it would unlock this camera’s video capabilities for many of us, and burnish their film making credentials for them.

 

Happy creating!

 

 

Sent from my iPhone using Tapatalk

 

 

I agree with Peggers approach to managing exposure when shooting log. Correcting for underexposure in the field by making adjustments in post will often exacerbate noise. So indeed, "expose to the right," as so many say. However, use care not to overexpose too much. Once you've clipped highlights, there's nothing you can do to recover them. 

 

Tom

[Roddy]

I forgot to mention that ISO was set to 200 and opened to f4 - a stop under exposed. When I pushed to 400 it seemed to disappear. However, with camera set to 200 in a well lighted room full of sunshine and over exposure by a few stops the screen on the SL was crazy full of banding noise. Auto and Floating ISO are off, and camera is in manual. I am a Director of Photography, own a Red Epic W and have been shooting raw and log for years. It feels like there is a setting somewhere that I am missing.

[Roddy]

By the way, thank you for responding. 

[Michael Hodges]

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I'm in the same boat Roddy.  I did a limited amount of testing in a controlled setting and found that I really needed to create my own LUTs in Resolve before I was satisfied with trying on a professional shoot as a B-Cam.  I definitely need to continue my testing but after doing a bunch of motion and lighting tests (with charts) at various exposure settings I ended up treating it like a motion picture film camera at ISO 200 while locking shutter speed at 1/50 (as close to 180 degree shutter as possible for a given FPS).  I've gotten good results but found that the calibrated Odyssey or PIX was necessary until I learn to anticipate the camera's "signature" better.

[peggers]

Guys,

 

I did a small piece of work this afternoon - shooting a scene of a fair dynamic range at 50, 100, 200 and 400 ISO. At each ISO I exposed as metered, and +1EV, in vLog format. I don't think this film is going to make the Oscar short list btw.

 

Nonetheless, I then applied a curve in Final Cut Pro, with a big boost to saturation to dial out the vLog exposure. Finally, I also shot at 400ISO, with -2EV expose, and applied the ARRI LUT available in FCP X, that a few people use.

 

Please see the results here (ensure Quality is at 1080p):

 

 

Basic observations for me:

 

1. Best results were at correct exposure - no visible noise in shadows. The shots were effectively 'exposed-to-the-right' to use the term (I always thought "exposed-from-the-right" would have been better term but I am often wrong on so many things)

 

2. Over-exposure blocked up highlights

 

3. Under-exposing by 2 stops to use ARRI / Sony LUT will introduce lots of noise.

 

4. Based on my in-door work, it is best to expose to the right using the histogram, as it is easy to underexpose based on pure meter reading and introduce quite a bit of noise later

 

Some caveats:

 

1. These are 1080p 24fps not the 4K OP mentioned

 

2. All recorded in 4:2:0

 

So this camera can definitely perform, but without an external monitor that can apply a custom LUT live, one is going to have to religiously follow the histogram and 'expose-from-the-right' :-). Correct exposure is vital to avoid grain in the shadows. I've had good results at 3200ISO / 1080p 24fps

 

So probably time to attempt my own LUT now - unless Leica would produce one, or in v4 of the firmware produce a waveform display!

 

Let me know your experiences.

 

Phil

Edited January 25, 2018 by peggers

[Michael Hodges]

Thanks Peggers.  Tests like this are helpful and it's good to see so many people showing more interest in seeing what this camera is capable of.

[tpf1952]

My thanks to Phil as well. I’ll get over myself and double down on getting better performance from the SL.

[peggers]

My thanks to Phil as well. I’ll get over myself and double down on getting better performance from the SL.

 

 

Ah - tpf1952 - don't be so hard on yourself. I went back out today and tried to apply what I had learnt - it hasn't gone well. Although I set the white balance using a grey-card, and metered carefully via the histogram, I have been left with lots of noise in those shadows.

 

Sometimes I do get good footage - often not. Its just to too hit and miss. And the files seam to need a huge boost to the saturation in post. I am now considering going back to using non-log format.

 

Is it just me, or do people feel that perhaps Leica either need to tweek the vlog implementation again, so that it can be graded easily and avoid noisy shadows. And/or Leica should say more about how to process, and provide a v-log to REC709 LUT?

 

Does anyone have a contact with the SL product manager?

[BernardC]

Is it just me, or do people feel that perhaps Leica either need to tweek the vlog implementation again, so that it can be graded easily and avoid noisy shadows. And/or Leica should say more about how to process, and provide a v-log to REC709 LUT?

 

Does anyone have a contact with the SL product manager?

 

I agree with you. Leica does not provide an ACES IDT, or even simple LUTs, for "L-log".

 

People have reported some success using LUTs designed for Sony or Arri cameras.

Sony S-Log LUTs are non-starters for me, making blue skies look like blueberry trifle. Some Arri LUTs are closer, but still not close enough to use as anything more than a helpful preview. I either create my own custom correction from scratch, or shoot in Rec-709 (non L-log) mode. This reminds me of shooting on motion picture film, where the available range of "post fixes" is much less extensive. It's not a bad exercise, but it's hardly optimal.

 

The product manager of the SL System is Steffen Skopp. I don't have his contact information, but I'm sure that Leica customer support would be glad to forward a message to him.

[TealWayFilms]

There are a several very important factors I have found influence noise when shooting video with the SL and log settings. Some have been alluded to above, but I thought I would start to compile a list that might be helpful to the Leica product development team

 

1) I haven’t found l-log to be helpful with internal recording 4:2:0. I use FCPX, and any manipulation gets muddy quickly at any ISO.

 

2) Log does help with my Atomos Assasin external recorder at low ISO. Part of that may be 10 bit, Prores codec, or better exposure control with the features of the Atomos software. I have much better results with grading.

 

3) As others have noted, higher ISO’s result in shadow noise, worse with an external recorder. Seems the noise reduction is completely turned off to an external feed.

 

I completely agree that Leica should be giving us filmmakers more guidance in how to use this tool. I continue to use a Sony A7s for high ISO work, and understand that Leica doesn’t have the opportunity to use the best sensors. I would like them to compensate by offering superior customer service to the video community, especially with a tool like the Leica SL.

[tpf1952]

Thank you, Teal Way Films. Your experience with L-log, noise, recorders, and the A7s alternative mirrors my own. I’m going to keep trying to tame the noise on L-log, but not on a paid project.

[Irakly Shanidze]

I've been using SL with Blackmagic Video Assist 4K for 4:2:2 10-bit recording either on ProRes, or ProRes HQ. I record internally only at 120fps, as Blackmagic recorder does not support this mode.

Using mentioned -2EV + Arri C and Sony sLog LUTs (lately gravitating more to the ARRI LUT) I get clean l-Log footage at ISO 50-200. Anything above requires considerable noise reduction in DaVinci Resolve Studio, if the project requires no grain. What I also found is that Leica SL grain looks rather film-like, and most of the time I can get away with it.
This clip was shot at ISO400 to 3200 (the 3200 part is easily identifiable at 0:45-0:47), and most clips did not go through noise reduction. Of course, Youtube butchered it, and in many cases the grain transformed into ugly pixilation.

 

 

The idea of exposing for shadows with manual Log adjustment made me curious. I am going to try it this week.

[Irakly Shanidze]

I'm in the same boat Roddy.  I did a limited amount of testing in a controlled setting and found that I really needed to create my own LUTs in Resolve before I was satisfied with trying on a professional shoot as a B-Cam.  I definitely need to continue my testing but after doing a bunch of motion and lighting tests (with charts) at various exposure settings I ended up treating it like a motion picture film camera at ISO 200 while locking shutter speed at 1/50 (as close to 180 degree shutter as possible for a given FPS).  I've gotten good results but found that the calibrated Odyssey or PIX was necessary until I learn to anticipate the camera's "signature" better.

Michael, this is exactly what I do: ISO200 and 1/50 at 24fps. 

Blackmagic Video Assist 4K is capable of live LUT application, which makes it entirely possible to judge the correctness of exposure by eye.

[Matthieu]

More than a year later now... is somebody found the best setting or found/create a lut ?

thanks from Belgium 🙂