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D j Harris
Fs7 grain
on Mar 16, 2017 at 5:13:06 pm

Hi,

I'm asking this question from the perspective of post production - we have an Fs7 but we often seem to have terrible trouble with grain and digital pixelly noise, particularly in dark areas. Any kind of grading seems to make it worse. I've downloaded the Sony LUTs, but can't say they help massively either. I'm wondering if there something in camera set up or using a particular ISO (it's normally on Cine EL which I think is 2000) that can help this. Just spent a whole day degraining shots...

Thanks in advance


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Todd Terry
Re: Fs7 grain
on Mar 16, 2017 at 5:40:05 pm

I can't speak with a ton of authority since I'm not a Sony guy (I shoot Canons), but are you saying that the "normal" Sony recommended and default ISO is 2000??? That is high. Not just high, but sky high. For most of the Canon EOS pro line (such as the C300 which I shoot) the optimal ISO is 850, and I think that is fairly in line with most flavors of cameras these days (and just a few years ago even 850 was considered astronomically high).

If you are shooting at an IS0 of 2000 and having grain/noise issues, I'm 99% sure that is the complete and total source of it. Unless you are shooting in extremely dark environments, have very slow lenses, and are shooting at high f-stops, there's no reason to shoot with it that high. Aim for shooting with the lowest ISO you can, and I think your images will be much cleaner.

T2

__________________________________
Todd Terry
Creative Director
Fantastic Plastic Entertainment, Inc.
fantasticplastic.com



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Rick Amundson
Re: Fs7 grain
on Mar 16, 2017 at 6:06:01 pm

Todd, you'll have to believe it because it's true.

The native ISO is 2000. There is definitely a learning curve with the FS7 but it's worth the time(it doesn't really take that long). Here is the best place to get the answers you seek.

http://www.xdcam-user.com/2014/12/ultimate-guide-for-cine-ei-on-the-sony-px...

Contrary to former rules, the key is to over expose the Slog3.cine by 1/2 to1 full stop and correct in post. That will help your grain issue. Allister really has the system down and I learned most of my tricks from his posts and I have to say, I've shot some good looking stuff for the last 2 years.

Good luck.

Best of luck!

Rick Amundson
Producer/Director/DP
Screenscape Studios
Bravo Romeo Entertainment
http://www.screenscapestudios.com
http://www.bravoromeo.com
http://www.indeliblemovie.com


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Todd Terry
Re: Fs7 grain
on Mar 16, 2017 at 7:06:56 pm

Good gawd, 2000 as the default?... that is dumbfounding, but of course I believe you, Rick. I'm glad that I prefaced my post with my admission of my lack of knowledge about Sonys these days (I used to shoot Sony, but not in the past 15 years or so)... but apparently I went on to prove my ignorance.

Man I would find that so restrictive, and am now doubly glad I'm still shooting Canons... with the Sony I'd be piling on the ND filters all day (which I hate doing). Frankly I find 850 with the Canon much too high for my taste about 95% of the time as it is. The C300 will go up to 80,000 ISO, but frankly I don't think I ever push it past about 1250 or so.

I'm thinking about our old 35mm days when shooting 5203 was the go-to filmstock and we just accepted ASA 50 as the "norm".... and I used to hate shooting 5219 because it was so darn grainy but we would marvel at its ASA 500 as something unbelievably fast. Times certainly change.....

T2

__________________________________
Todd Terry
Creative Director
Fantastic Plastic Entertainment, Inc.
fantasticplastic.com



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Richard Herd
Re: Fs7 grain
on Mar 28, 2017 at 5:19:02 pm

2000! Holy crap. This brings up so many questions!

Do you have a depth of field chart for the FS7? I googled of course but it was hard to suffer through all the noise.

Thanks!


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Blaise Douros
Re: Fs7 grain
on Mar 16, 2017 at 8:32:40 pm

Hey DJ, I think I can help.

First, I need you to tell me what color space, resolution, and codec you're shooting in. Then, I need to know what mode you're shooting--Cine EI, or Custom? If Custom, how is it set up? I also need to know how you're exposing the image--are you exposing just by looking at the image in the monitor, or using scopes, an 18% grey card on set, etc...? Using MLUTs in the viewfinder?

The bottom line is that I think whoever is your DP doesn't really understand how to expose for log footage. Here's what happens: you get the log footage on the monitor, and when correctly exposed, it looks super washed out. So in order to make it look good on the monitor, the DP drops exposure, which makes the image look contrasty and better on the monitor. Only it's not--it's underexposed now, so you end up with ultra-dark shadows with grainy noise when you try to brighten it. So even when using a LUT, you have to bring the footage way up in brightness for it to look good...and consequently, you get grainy shadows.

You MUST understand how log color spaces relate to Rec709 before you shoot in them. Skin tones, for example--we're trained to keep them at 75-80 IRE on the hottest spots. But in Slog3, the hottest skin tones should sit at 60-62 IRE. That's a HUGE difference. Blacks, which sit at 6 IRE on Rec709, end up around 18-20 IRE on Slog3. So if you place the blacks down at 6, where we're trained to put them, we grossly underexpose the rest of the image.

Does this sound like a plausible explanation for what might be going on in your footage? I have seen this issue probably 15-20 times with shooters new to shooting in log color spaces, and that's exactly what it sounds like to me.

To be clear, I'm not saying anyone is negligent here--I learned this lesson the hard way myself. It's an incredibly easy mistake to make, and I made it on several shoots myself before I figured it out.

To address some of the prior points:

Yes, the native ISO of the FS7 is 2000. It has very minimal noise at that ISO when exposed correctly. It shoots at that ISO to preserve the native 14 stops of dynamic range that the FS7 can produce when correctly exposed at that native ISO shooting Slog3. You can certainly drop to lower ISOs, but you sacrifice a bit of dynamic range (not a significant amount, but some).

And to address your comments, Todd, yes ISO 2000 does seem high until you know that the FS7 has three built-in physical ND filters: 1/4, 1/16, and 1/64, so exposing at ISO 2000 in full daylight is no problem whatsoever.

Of course, since ISO is totally unstandardized, ISO 2000 on the FS7 seems to be closer to 1200 on some of the other cameras I shoot with it. That's a standard that REALLY needs to be resolved!


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Todd Terry
Re: Fs7 grain
on Mar 16, 2017 at 8:45:27 pm

[Blaise Douros] "And to address your comments, Todd, yes ISO 2000 does seem high until you know that the FS7 has three built-in physical ND filters:"

I hear ya, Blaise... my C300 has the same three built-in ND filters (so does the C100, although with the C100 you have to manually turn a thumb wheel like an animal, whereas with the C300 it's just pushing a button). But still, since I like to shoot pretty wide open (it's not uncommon for me to shoot a whole project at f/1.3), even with the internal ND dialed to the max it's not uncommon for me to have at least .9 extra ND in the matte box, sometimes more. Oh well.

Good of you to help out D j, I think you gave good info and are definitely on the right track.

T2

__________________________________
Todd Terry
Creative Director
Fantastic Plastic Entertainment, Inc.
fantasticplastic.com



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Blaise Douros
Re: Fs7 grain
on Mar 16, 2017 at 9:53:33 pm

Yeah, I haven't really shot the C-series much, so I'm in the opposite (or same?) boat. I'm sure you've got a good shooting setup dialed.

It's such a common problem with new FS7 shooters, Sony should supplement the manual with an Slog3 exposure guide. Luckily there are guys like Alister Chapman out there to do it for them, thought I don't completely agree with all of his shooting advice.


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D j Harris
Re: Fs7 grain
on Mar 17, 2017 at 11:26:53 am
Last Edited By D j Harris on Mar 17, 2017 at 12:34:17 pm

Hi Blaise,

Thanks for replying - I believe that it's shooting S-log3/1080p/XAVC-i/2000 ISO/Cine EL. The viewfinder is set to a LUT/Look Profile (2.LC-709typeA). I've just spoken to one of the cam ops and he says he usually sets zebras to 90%. We sometimes shoot in just 709 depending on the client, in which case zebras are at about 72%. They also use the Hypergamma setting, switching between HG3 and HG4 for indoors/outdoors. They also use a shutter angle of 180 degrees. Interesting to learn that ISO isn't standardized, I didn't know that!

We are a small company and it's mainly used on small & fast corporate shoots so is exposed just by using the viewfinder. I did some research prior to this and ask on the last shoot if it could be slightly overexposed as you suggest, which did seem to help matters - there's probably more we can do though. The cam ops are asking if there is way of saving profiles onto an SD card so they can load up settings quickly on a shoot - I will look into this but you might know if this is practical to do!

Thanks again


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Blaise Douros
Re: Fs7 grain
on Mar 17, 2017 at 3:47:29 pm

Okay, sounds like you guys are mostly getting it right. A couple of things to check--Make sure you're on the latest firmware, version 4.0. Custom mode on the FS7 has noise reduction applied automatically. In versions 3.1 and up, NR is available in CineEI, but you have to turn it on; I can't remember the menu path, but you can set it to Low, Medium, or High. That helps right off the bat with some of the shadow noise--it's a very good NR algorithm.

You need to verify that the LUT the cam op is using is really the technical LUT from Sony, not one that was generated via LUTCalc. It's easy to make critical mistakes when creating those from scratch. There are also a bunch of LUTs floating around from Alister Chapman that are designed to make the camera op reactively over-and-underexpose the image to preserve highlights or shadows depending on the situation, and if one of those is being loaded, it may be causing them to underexpose unintentionally.

Also make sure that the LUT is the correct one for the Slog3 flavor they're using; there's a difference between Slog3.Sgamut and Slog3.SgamutCine, and the MLUT that they use on set should reflect that.

Finally, to answer your question, yes, the FS7 has a very robust profile system that allows you to save a bunch of different profiles to the SD card--that's why it has the slot in the first place. You can save everything from Paint and color setups to full camera setups.


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D j Harris
Re: Fs7 grain
on Mar 17, 2017 at 4:46:08 pm

Hi Blaise, thanks - yes, I'd seen the NR option in the menu and was about to do some tests with it - I think we left it off by default as often these in-camera image processing things aren't great, but if this one works then fantastic! I don't know which LUTs they are using in camera, but I'll check it out. Thanks for the help.


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Blaise Douros
Re: Fs7 grain
on Mar 17, 2017 at 5:52:02 pm

Definitely make sure, too, that if they're in a situation where they need shadow detail, that they overexpose at least one stop so you can crush the blacks later. Same for highlights--underexpose for extra detail there. Of course, they should notate this if possible.

On other piece of advice I can offer you when working with log footage: if you need to make global adjustments to exposure or white balance, make sure that adjustment comes BEFORE the LUT in the effect order. The LUT applies a logarithmic curve to the flat footage, so the highlights and shadows get crushed faster if you're adjusting brightness after the LUT in the effect order.

Lumetri Color applies the LUT before any other effect in its panel. This means that if you need to globally adjust the footage, you need to use two Lumetri effects: one to apply the exposure adjustment or white balance correction, and then another one to actually apply the LUT and tweak refinements. I know this sounds overly complex, but you get very different results depending on where you apply exposure or WB adjustments in the effect order.


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D j Harris
Re: Fs7 grain
on Mar 20, 2017 at 11:28:13 am

Hi Blaise,

Ok, sounds good, yes I was just using one Lumetri effect (we just switched to Premiere recently so not fully up to speed with it yet).

I did have one question actually, I've just set the camera up to do some tests so we know what we are doing and what effect things have - I did have a question about the gain switch when in Cine EL mode - I am confused about what it is actually doing. It seems to indicate it is changing the ISO somehow (from the menu display) from 800/1600/3200 but I gather this isn't what it's really doing, I have read some things that seem to indicate it's something you do in post, but I don't understand what. I think we usually shoot with it it the low position. Any recommendations here?


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Blaise Douros
Re: Fs7 grain
on Mar 27, 2017 at 11:22:06 pm

In Cine EI mode, the ISO does not change when you change the setting. It is always set to 2000. However, you can "rate" it the way you would a film stock by pushing or pulling the image in post based on the Exposure Index (EI, get it?) you've set in the camera.

If you have an MLUT applied, and you change the ISO/Gain setting, the MLUT will show you what the image would look like if you had set that ISO, but the camera will still record in 2000. What this does is allow you to see a clean, correctly exposed image in the monitor, while still shooting to protect either highlights or shadows (depending on the situation). Let's say you want to protect highlights; you raise the Exposure Index by a stop, which means you will end up adjusting the exposure down a stop to compensate. In post, the image will be underexposed by a stop, but the highlights will be protected.


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