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  • Hey all, just changed over the backend after 15 years I figured time to give it a bit of an update, its probably gonna be a bit weird for most of you and i am sure there is a few bugs to work out but it should kinda work the same as before... hopefully :)

Excessive Noise on Epic Green Screen shoot

We shot last week with our Epic with Tungsten @ 800iso on green screen and the results are fantastic!
5k 2:1 Redcode 7:1
 
Josh Beadle said:
Define "every shot". You mean like once a day, at each power up or before every shot you take? What is the prescribed frequency and why? RED TEAM can jump in here at any time.
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I said every shoot, not every shot. Huge difference. All I'm saying is set aside some time to black shade before you start rolling on a shoot in a new condition. Why is that so difficult to understand?
 
I just shot 4k green screen 800iso 3:1, no problems. Image looked amazing.

Quick question on black calibration: If you need to do it on every shoot, do you need to do it every time you turn the camera off?
 
Chris Zamoscianyk said:
I just shot 4k green screen 800iso 3:1, no problems. Image looked amazing.

Quick question on black calibration: If you need to do it on every shoot, do you need to do it every time you turn the camera off?
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You shouldn't need to do it every time you turn off the camera.

Jarred and Jeff mentioned that it is best to do black calibration after the camera has warmed up and if you've changed into a different condition (temperature difference between locations). This will allow you to gain the best results.

Since I've been shooting a lot of material outside lately, I'll always black shade, especially since I'm shooting high speed stuff with variations between sun and shade.
 
Black shading takes 12 minutes but it uses a battery. If like me you only have 4 and probably need them all for any given shoot I suggest buying an AC adapter.
 
Another reminder is to Black shade once the camera has been on for a while and warm.

If you are going to do long exposures at night for example, it is imperative to black shade the camera.

David
 
Mark Deeble said:
It would be really good to have RED come in on this - it's a question that has been raised several times before and user suggestions seem to be to black balance:

1. After a change of frame rate
2. After a firmware update
3. After a big temperature change

I regularly change fps several times an hour when shooting wildlife EFP and it is simply not feasible to black balance every time, so I don't - especially as there is no knowing which speeds I am going to need.
When shooting cineform RAW with a Si2K I would black balance once when the camera was switched on and then when the temperature had stabilised and after any big temperature change (10 deg C) thereafter. The black balance on that camera takes a few seconds so there is little down time if the operation needs to be done several times a day. Black balance on the Epic seems a more complex operation and takes much longer and can result in significant downtime, especially if it needs to be done in the middle of a day's shooting.
What is the advice?
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I too work often on shoots where a black calibration on every change of framerate with Epic's long calibration times would be completely impractical. What I've found works is to calibrate once a day after working temperature reached at the base framerate ( 24/25/30fps ) at the start of the shoot and it's fine for faster framerates, but I would then definitely recalibrate for lower framerates than the base framerate.

Also after firmware update and BIG temperature changes.
 
ericyoung said:
I too work often on shoots where a black calibration on every change of framerate with Epic's long calibration times would be completely impractical. What I've found works is to calibrate once a day after working temperature reached at the base framerate ( 24/25/30fps ) at the start of the shoot and it's fine for faster framerates, but I would then definitely recalibrate for lower framerates than the base framerate./QUOTE]

That sounds good advice - thanks. I don't think I've had any problems arising from infrequent or untimely black calibration - nothing I have seen on reviewing material, but I'd rather not get a nasty surprise when I get back to base after a two month shoot (!).
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Hm... Am I the only one without huge blackshade issues on the Epic? :)

Shot GS Tungsten - worked like a charm

Swapped between 120 and 24
Worked like a charm

I am probably just a very lucky guy.

Blackshading is important, for sure, but don't make that an issue on level with the R1 startup times. Cause it isn't.

Lights are more important than blackshading, even when you shoot GS...

It's better to have enough tungsten than too little HMI.

LOL

G
 
Gunleik Groven said:
Hm... Am I the only one without huge blackshade issues on the Epic? :)

Shot GS Tungsten - worked like a charm

Swapped between 120 and 24
Worked like a charm


I am probably just a very lucky guy.

Blackshading is important, for sure, but don't make that an issue on level with the R1 startup times. Cause it isn't.

Lights are more important than blackshading, even when you shoot GS...

It's better to have enough tungsten than too little HMI.

LOL

G
Click to expand...

I asked Deanen about Black Shades & he said it's only necessary at extremes of exposure like 1/1000 so in normal shooting you dont need to re do.

I did some Green Screen tests to 'destruction' a couple of weeks ago , my conclusions:-

Add 1/4 blue to tungsten
Rate the sensor nearer 500 ISO, as the headroom is not usually necessary in a green screen scenario.
Use a low compression 5:1 or less.

I am not going to publish any material & YMMV.

Many people will be happy with 800 ISO & 10:1 compression, however if your looking for the VERY BEST, following my advice will get you in the ballpark. I am happy to Own an Epic, for Greenscreen it's as good as it gets if you know what your doing.
 
This sounds like a case of accidentally underexposing because the gain for the 3 channels was set high. Blackshading is important, but this seems like a pretty open and shut case. 99% of exposure problems come when someone sets and extreme look on the camera and then they make poor decisions because of what they see on the monitor.

An extreme example of this would putting the camera into REDLogFilm and then stopping the iris down for a "good exposure" I've never heard of anyone doing it yet, but I'm pretty sure it will happen someday. A less extreme example is when people turn the ISO up, and then stop down. It's not RED's fault and it doesn't mean Epic/Scarlet are bad, it means that you have to use the additional exposure tools that RED has put in the camera.
 
Stephen Williams said:
I asked Deanen about Black Shades & he said it's only necessary at extremes of exposure like 1/1000 so in normal shooting you dont need to re do.

I did some Green Screen tests to 'destruction' a couple of weeks ago , my conclusions:-

Add 1/4 blue to tungsten
Rate the sensor nearer 500 ISO, as the headroom is not usually necessary in a green screen scenario.
Use a low compression 5:1 or less.

I am not going to publish any material & YMMV.

Many people will be happy with 800 ISO & 10:1 compression, however if your looking for the VERY BEST, following my advice will get you in the ballpark. I am happy to Own an Epic, for Greenscreen it's as good as it gets if you know what your doing.
Click to expand...

Fits well with my findings.

I just want to get the message through that it is better to have enough tungsten, than to cripple the other channels as well (green and red).

If you're in controll of everything, there's nothing wrong at shooting at 320, when you don't need the headroom. GS shots are typically the most high contrast ones...

But as you say

YMMV

Cheers

G
 
So HERE is a photobucket link to a still from the video.

Sorry it's not a video and sorry it's a JPEG I've not got much hosting abilities. So everyone seems as split as I do whether it's black shading issue or just plain underexposed. I suspect a combination of both. Operator error will always happen and I suspect a lot of the blue noise is due to 800iso under tungsten but I also think it might be left unkeyable due to black shading issues.

Even if black shading is not to blame it scares me that this is something which has no instructions from Red on what to do.

I too have no desire to have to black balance every morning. If it takes 1 minute it's a pain but 12 minutes is horrendous. 12 minutes of on-set time every day? After the camera has warmed up for an hour? No way. I'd rather the 2 minute start up of the Red One. Is this what we can expect the whole time or will it be solved in future builds? For the time being I'll be putting a massive sticker on the camera saying "Black Balance or Else". From the sound of things it's not like it can even be done in the kit room before the camera goes out.

If it's a time thing can the camera have an alarm on it. If it's a temp thing can the camera please tell us when it is so hot it needs to be black shaded. If it's a shutter and frame rate thing can the camera please prompt each time the settings are changed? What if you're shooting a documentary? ("Can you please ask that elephant to stop giving birth for 12 minutes I need to black shade the camera now the sun has come out?")

At the very least can the User Guide say in big old letters that Red recommend a daily black shading, instead of being tucked away on a message board, and that's from someone who check reduser most days. The shoot had a DIT on it who I did not supply or know, they are used to Red One footage but not Epic. Should they have known to watch out for this sort of thing?

If it's operator error or black shading error makes little difference I guess; currently I'm looking at at supplying a reshoot which, at a minimum, will require free of charge camera, lenses, lights etc costing a good couple of thousand for the day. At worst if we decide it's a camera issue it'll cost the full £10k budget of the promo not to mention the waste of time and effort of everyone who was involved in the original shoot.

Ben
 
It says the address isn't valid...

A single r3d frame would be much more informative.
You could mail it to me, and I could host it...

Cheers

Gunleik

gunleikgroven at gmail dot com
 
Problem is simple.... This is seriously underexposed. I think I can get a usefull result for a 1080 delivery, though...

It wouldn't have hurt with some additional lighting coming not from the front, either...

But I can key it ok and get rid of the noise...

next!

:)
 
You underexposed by roughly a stop. This would be due to the gain being set to 1.8. At REDcode 12:1 [necessary for 120FPS], the consequences are exacerbated.

No shading problem that I can see. The settings on the camera were simply incorrect and it led you to underexpose.
 
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benedictspence said:
Even if black shading is not to blame it scares me that this is something which has no instructions from Red on what to do.

I too have no desire to have to black balance every morning. If it takes 1 minute it's a pain but 12 minutes is horrendous. 12 minutes of on-set time every day? After the camera has warmed up for an hour? No way. I'd rather the 2 minute start up of the Red One. Is this what we can expect the whole time or will it be solved in future builds? For the time being I'll be putting a massive sticker on the camera saying "Black Balance or Else". From the sound of things it's not like it can even be done in the kit room before the camera goes out.

If it's a time thing can the camera have an alarm on it. If it's a temp thing can the camera please tell us when it is so hot it needs to be black shaded. If it's a shutter and frame rate thing can the camera please prompt each time the settings are changed? What if you're shooting a documentary? ("Can you please ask that elephant to stop giving birth for 12 minutes I need to black shade the camera now the sun has come out?")

At the very least can the User Guide say in big old letters that Red recommend a daily black shading, instead of being tucked away on a message board, and that's from someone who check reduser most days. The shoot had a DIT on it who I did not supply or know, they are used to Red One footage but not Epic. Should they have known to watch out for this sort of thing?

Ben
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I would love to hear more details about when black shading needs to be done in Epic. And is it the same in Scarlet as well? While filming wildlife, there is no chance of reshoot. One often witnesses different conditions warm sunshine and then cloudy or moving into shade in the forest. Especially, since in India we don't have huge open grasslands like Africa.
 
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