Blackshading--WHY?

[Kenneth C Merrill]

One of the big reasons I ordered a Raven is because I really hate black shading. I was under the misconception that the DSMC2 bodies can do a sort of auto calibration based on your exposure time and working temperature. I've just realized now (after some research) that this is not the case. While DSMC2 cameras can calibrate multiple exposure times at once (awesome!) they cannot handle varying temperatures without another black shade (bummer). So I have a couple of questions.

1. What kind of tolerances do these cameras have? If I go from a 90 degree environment to a 65 degree environment, will I be screwed without a black balance? With my Scarlet MX I'm seeing the yellow or red "T" even with a variation of about 15 degrees.

2. Why in the world do we have to do this on Red cameras? I've been on plenty of shows with the Alexa, and we never blackshade or anything like that with the Alexa. What is it doing that the Weapon/Scarlet-W/Raven does not?

 

[PatrickFaith]

I keep the fan setting on auto at 37 (and I do the bs at that temp), so that Black Shade seems very stable between 35 F to 92F. I think the bs is more important if your drastically changing the shutter/fps, which I hardly ever do since I am 99% of the time at 24 fps / 180 shutter. If your in hotter environments you might want to put the auto fan speed higher then bs at that, then you can focus on the creative part and not mess with bs.

 

[Luca Volpe]

Just a question: if you keep the fps base project and you change the fps at lets say 60(vary speed) do you need to do the bs?
thanks

 

[Kenneth C Merrill]

Just a question: if you keep the fps base project and you change the fps at lets say 60(vary speed) do you need to do the bs?
thanks

The only things that affect your blackshade are temperature and exposure time. Since changing the frame rate would entail changing the exposure time, yes you would need to blackshade again. But from what I understand, the new Auto Blackshade feature will do a calibration for multiple exposure times at the camera's current temperature. In that case you would just need to bring the camera up to temp, do an auto BS, and you could switch between 24 and 60 all you want. It's when the temperature changes that you might have an issue.

My big question here is really why we even have to worry about this. Sony and Arri seem to have it figured out...

 

[Christoffer Glans]

I haven't done an auto black shade on mine yet, but the theory is to do an auto-cal in different temperatures so that if you shoot in cold weather, you have one auto-cal set and if you shoot in-doors or in "normal" temperatures you have another, then one in hot temperatures like non-air cooled studios or deserts. You really would only need to have three sets of auto-cals to choose by and... how many times would you really choose between those?

 

[PatrickFaith]

The only things that affect your blackshade are temperature and exposure time. Since changing the frame rate would entail changing the exposure time, yes you would need to blackshade again. But from what I understand, the new Auto Blackshade feature will do a calibration for multiple exposure times at the camera's current temperature. In that case you would just need to bring the camera up to temp, do an auto BS, and you could switch between 24 and 60 all you want. It's when the temperature changes that you might have an issue.

My big question here is really why we even have to worry about this. Sony and Arri seem to have it figured out...

hmmm... You don't respond to me, then you belittle red on a obvious question that can be easily googled. Might be your not ready for RED.

 

[Phil Holland]

One of the big reasons I ordered a Raven is because I really hate black shading. I was under the misconception that the DSMC2 bodies can do a sort of auto calibration based on your exposure time and working temperature. I've just realized now (after some research) that this is not the case. While DSMC2 cameras can calibrate multiple exposure times at once (awesome!) they cannot handle varying temperatures without another black shade (bummer). So I have a couple of questions.

1. What kind of tolerances do these cameras have? If I go from a 90 degree environment to a 65 degree environment, will I be screwed without a black balance? With my Scarlet MX I'm seeing the yellow or red "T" even with a variation of about 15 degrees.

2. Why in the world do we have to do this on Red cameras? I've been on plenty of shows with the Alexa, and we never blackshade or anything like that with the Alexa. What is it doing that the Weapon/Scarlet-W/Raven does not?

1. DSMC2's entire ventilation system and general thermal architecture are different from DSMC bodies. Higher tolerances and better cooling are part of what the new system does well. It's hard to know exactly what ranges a given calibration will play well with, but I've had warm days into cool nights that worked fine. Extremes variations are really what you need to be on the lookout for.

2. RED's Sensor Calibration process is part of the procedure to capture the highest quality possible images out of the camera. Arri's method of Defect Pixel Correct (DPC) and Black Balancing come in the form of image processing via hardware. It's a different technique than RED, Sony, and Panasonic utilize.

My big question here is really why we even have to worry about this. Sony and Arri seem to have it figured out...

Sony has APR, or Auto Black Balance on the F55.


The longer answer to much of this is maintaining high quality pixels, in the case of RED a lot of high quality pixels, as well as examining and counter acting the fixed noise pattern. I've met more than one individual who has never Black Shaded their camera nor paid attention to the temperature and exposure notifications. While you can do whatever you want, don't be that guy. Run a Sensor Calibration ahead of a shoot during prep or at the beginning of the week or month. Whatever floats your boat. If you suddenly are in the arctic, you should likely do that again. Then if you find youself back in Death Valley, yep it's a great idea. And somewhere between the heat and cold environments, there's firmware updates. After you install a firmware, you should run a Black Shade.

 

[Gene Sung]

I haven't done an auto black shade on mine yet, but the theory is to do an auto-cal in different temperatures so that if you shoot in cold weather, you have one auto-cal set and if you shoot in-doors or in "normal" temperatures you have another, then one in hot temperatures like non-air cooled studios or deserts. You really would only need to have three sets of auto-cals to choose by and... how many times would you really choose between those?

Would this work?

If someone who really knows what they are doing like Phil Holland or even Red, were to offer a set of good Auto Black Shades I would gladly buy it off them.

ABS in a walk-in refrigerator to simulate cold winter, another for mild Autumn temperatures, my S-W came with a stock 40 Celsius which I am assuming is for the average room temp, then a final ABS done in a dry sauna to simulate shooting in the hot desert?

The camera stores 4 profiles and it seems like BS would be much less an issue as you just have to pick one of the trusted ABS done by a Red technical expert then a majority of shutter speeds and temps are covered.

 

[Kevin DeOliveira]

Would this work?

If someone who really knows what they are doing like Phil Holland or even Red, were to offer a set of good Auto Black Shades I would gladly buy it off them.

ABS in a walk-in refrigerator to simulate cold winter, another for mild Autumn temperatures, my S-W came with a stock 40 Celsius which I am assuming is for the average room temp, then a final ABS done in a dry sauna to simulate shooting in the hot desert?

The camera stores 4 profiles and it seems like BS would be much less an issue as you just have to pick one of the trusted ABS done by a Red technical expert then a majority of shutter speeds and temps are covered.

This does sound like a good idea, but I'm pretty sure the black shade need to be specific to YOUR sensor. The last thing you want is a mismatch between the calibration and your camera, which would look horrible.

Somebody chime in of Im wrong here.

 

[Gene Sung]

This does sound like a good idea, but I'm pretty sure the black shade need to be specific to YOUR sensor. The last thing you want is a mismatch between the calibration and your camera, which would look horrible.

Somebody chime in of Im wrong here.

ahhhh... Got it. That makes sense. Well, I'm going to find a walk in fridge today, LOL.

well, if this would work, once I learn how to Black Shade correctly (just got my S-W), I'll probably do something like this.

well, Auto Black Shade sounds awesome EXCEPT it says it can take up to 1 hour. On set, that could be a real issue, which is why some pre-made Auto Black Shades would be awesome.

if Red could somehow get Auto Black Shading to around 10-15 minutes, this would be a much smaller issue.

 

[Phil Holland]

ahhhh... Got it. That makes sense. Well, I'm going to find a walk in fridge today, LOL.

well, if this would work, once I learn how to Black Shade correctly (just got my S-W), I'll probably do something like this.

well, Auto Black Shade sounds awesome EXCEPT it says it can take up to 1 hour. On set, that could be a real issue, which is why some pre-made Auto Black Shades would be awesome.

if Red could somehow get Auto Black Shading to around 10-15 minutes, this would be a much smaller issue.

A couple of tips. Auto Sensor Calibration is a god send. Especially on commercial projects. Here's how it went down for me for yesterday's car shoot.

- Day before the shoot, setup camera and run the Auto Sensor Calibration.
- Next day, shoot. We filmed afternoon until about 5:30am btw. Camera temp was stable though the change of warmish day through cool night.
- Likely won't run another calibration this week.

If you find you are out of whack on set for a specific shooting environment. Look at the shutter speed you guys are using and run a single Sensor Calibration at that temperature and shutter speed. That doesn't take an hour, but is short of 10 minutes. I haven't even had to do this, but I think it's actually around 6-7 minutes typically, but it will depend on shutter speed.

I've had months since having Weapon where I've only ran one Auto Calibration for the whoooooooooole month.

I always prep and test camera first before any gig. There's where you'll find the time to whack out the calibration.

 

[Gene Sung]

Hi Phil,

How long does an Auto Calibration actually take on average?

The "This might take 1 hour" warning pops up and that what kind of freaks me out, so I'm wondering what the actual time is.

 

[Steve Sherrick]

Gene, be careful about old information. There have been previous firmware/builds where the process took longer, but as it stands now, it's more in line with what Phil is telling you. I would follow his lead on this one.

 

[Malik Tigrine]

The longer answer to much of this is maintaining high quality pixels, in the case of RED a lot of high quality pixels, as well as examining and counter acting the fixed noise pattern.

Do you mean that the ALEXA and the F55 don't need to maintaining high quality pixels?

Why RED doesn't take the same way? (like ARRI/Sony blackshading technologies)

 

[Gene Sung]

Gene, be careful about old information. There have been previous firmware/builds where the process took longer, but as it stands now, it's more in line with what Phil is telling you. I would follow his lead on this one.

Thanks Steve. Actually, The "Up to 1 hour" warning is what comes up on the Red Scarlet-W with Auto Calibration, not from an older thread.

I'll try it on an off day and time how long it takes. I know some people have mentioned 30 minutes, which might be do-able. Unfortunately, I'm not working on shoots as big as Phil, so lower budget means less time / more compressed schedule.

 

[Kabilen Mullaithilaga]

Questions re: Auto Sensor calibration and single sensor calibration.

Suppose you do auto-sensor calibration over night, getting it ready for the next days shoot.

You are unsure about weather (stupid climate change).

You shoot at 24fps for the most part, wait till the end to shoot fast action sequences that need 120fps or even 300 fps.

Do I need to do a single sensor calibration or auto sensor calibration between the change from 24 to 120fps? How about at the end of that day's shoot?

Suppose, due to lighting, I want to do all the fast action 120 fps scenes first, then should I do either single sensor or auto sensor calibration before I move to 24 fps. Then later that night do a full auto calibration?

Am I spoiling the system by doing so many calibrations?

Also, suppose due to compression ratios, I want to test out the many high frame rates + resolution combination... Should I do either single or auto calibration in between each and every change?

Again am I spoiling the system?

BTW, I am relatively new to RED (rented before, never did calibrations then) and I'm getting a Raven now, for the sake of longevity of my equipment, if someone can thoroughly answer that, it would be much appreciated. Thanks in advance.

 

[Tom Gleeson]

The Sky is falling

The Sky is falling

Kabilen,

I have been running a DSMC2 camera now for many months and the black shade (BS) issue is a non issue. When you do a FW upgrade do an auto black shade and that's pretty much it. Be sensible if it's winter and don't do your black shade in an overly heated room but remember there is a dynamic cooling system in the camera so it can easily cope with temperature variations. You could argue that maybe a winter BS and a summer BS may make some sense or you get that gig to the Sahara or the Antarctic.

I am not suggesting you don't do a black shade but I have shot with either the T or E lit up yellow in the camera and assuming you have a well exposed image I cannot see the difference.
Some people see things in a binary world and if something is not optimal it therefore must be a disaster and be bad. Just do a sensible black shade roughly approximate to your likely temperature conditions(is it summer or winter) and leave it at that. If you want to do more BS in your hotel room in your time there is no damage done but to hold up a shoot for multiple BS is just BS.

 

[Kabilen Mullaithilaga]

Kabilen,

I have been running a DSMC2 camera now for many months and the black shade (BS) issue is a non issue. When you do a FW upgrade do an auto black shade and that's pretty much it. Be sensible if it's winter and don't do your black shade in an overly heated room but remember there is a dynamic cooling system in the camera so it can easily cope with temperature variations. You could argue that maybe a winter BS and a summer BS may make some sense or you get that gig to the Sahara or the Antarctic.

I am not suggesting you don't do a black shade but I have shot with either the T or E lit up yellow in the camera and assuming you have a well exposed image I cannot see the difference.
Some people see things in a binary world and if something is not optimal it therefore must be a disaster and be bad. Just do a sensible black shade roughly approximate to your likely temperature conditions(is it summer or winter) and leave it at that. If you want to do more BS in your hotel room in your time there is no damage done but to hold up a shoot for multiple BS is just BS.

Thanks Tom,
I was just reading the stuff from the sticky in the "crucial ordinance."
Got to page 4 before I got tired of reading and mind started wandering.
Normally, I don't usually pixel peep... But I wonder how much FPN can be seen and identified by the general public.
Most of my stuff is done in low light, and at night... But I don't like to crank up the ISO, I bring enough lights (and sometimes a generator) depending on the shoot and location.
i guess I can settle with being in the yellow. Set it to dynamic not auto?

 

[Kenneth C Merrill]

Hey everyone! Thank you so much for your replies. It's been super helpful hearing more perspectives on this, especially since I don't have any experience with DSMC2. It's good to hear that black shading may not be nearly as big a deal as it is with DSMC1 cameras. That definitely puts me in a better mood about my Raven pre-order.

I will say (in case anyone higher up is listening!) that I wish Red had implemented something like Arri's automated DPC. I don't know much about the internal workings of either camera, but if automated black shading were an option, I would pay for it!

 

[Neil Dearman]

I was talking to a RED tech on Guardians of the Galaxy Volume 2 and he said they only black shade the camera one time and then never do it again. I still do the wait 15 mins and then black shade both my REDS (one a Weapon and one a Epic Body).