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Black Shading Tips

Blair S. Paulsen

Blair S. Paulsen

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I have shot a ton of material on RedOne #19 and only do the black shading routine when I install a new build. Lately I have been hearing anecdotal reports of people doing multiple black shades during the course of the shoot day, some even suggesting that as the temperature of the sensor changes this is necessary.

Physics suggests that the thermal state of many electronic devices does impact performance parameters. So:
1) How great of a temperature variation is necessary to impact RedOne/sensor results?
2) Are there changes should we be looking for?

Questions:
How often do you black shade?
Is the thermal issue a red herring?
Is there a risk of black shading "too much"?
Is there any guidance from the Red Team about how often one "should" re-shade even if everything seems fine? (in other words, are there subtle issues that black shading addresses that might be hard to spot on set, sort of like changing your oil and filter even if the car is running well)
Is Black Shading only indicated when installing new firmware or trying to resolve issues?

Other than extreme ambient conditions I have never had an issue. I have not personally seen temperature induced variations on set. Just trying to keep my powder dry...

Cheers - #19
 
Great questions- I hope someone from Team Red chimes in with an official word. Here is my $0.02:

For the first year I had my camera I only black shaded when I did a firmware upgrade. And I experienced no problems. For the last year or so my 1st AC has been black shading the camera prior to each days shoot in the environment that we are shooting in. And I still have not experienced any problems. The thinking behind this change was a recommendation from others who work on a Red shoot here in town (The TV Show Leverage). While I shoot a lot with Red, I can't say I shoot as much as a crew shooting a TV show with multiple Reds going at the same time. It seems to work for them, and it has not bit me yet.

The one thing I do know, is that it is best to reset the black shading to the defaults before doing a new black shading. Otherwise the new calculations will be based on the old calculations which may end up compounding black shading issues. So it is best to reset first.
 
As far as I know there are no counter-indications to properly done black shading. i.e. You can't hurt the camera with black shading.

You only need to do it when there is a major change to the setup or a problem. Firmware change, 3D beam splitter mounts, underwater housings- that sort of thing.

I've heard of people re-doing black shading when changing environments. I suppose if the environment change was extreme enough I'd give it a whirl. I don't usually do that though.

I usually perform a black shading before starting any project. I try to black shade once per week if I have a continuous shoot that long or longer.

The operating theory there is that on a long shoot problems or changes I may not have noticed (due to operational pace or simply gradualism of the change) can be accounted for.

That is almost certainly maintenance overkill.

So, you may have noticed the caveat "properly done." If you don't do a black shading that is supposed to be "bad." I don't know why exactly as I've never had a problem. The point is that the chances of a failed black shading have to be balanced with the amount of over maintenance you do.

I know these are probably not the definitive answers you need, and you can probably only the your "real" answers from the RED team. Since I haven't seen anything from them though, here is my 2 cents.
 
I -however- have noticed that when you are shooting under high temperatures IR pollution (I guess...) made me wonder about the need for a black shading... I mean that, even putting an IR filter in front of the camera, the IR pollution was there ... the only option left for me to try was to make a black shading, thus solved the problem. People at RED, any idea?
 
I had one black shading go awry, and it was unsettling. Re-did it and everything was fine. But I only black shade after a firmware upgrade now.
 
Do it:

On every firmware upgrade.
Before every rental.
Once a week on longer gigs.
If the temperature is 15deg C higher than the temp is was shaded at
If you see fixed pattern noise.
 
So Cali, have you seen FPN from cameras that heated up significantly during the course of a hot day? I am willing to err on the side of caution for obvious reasons but it would be great to know about anything specific I should be watching for.

Perhaps my eyes are not as good as I thought but I have never seen any difference between morning shots and afternoon shots even on hot sunny days. Is all this thermal stuff 99% FUD?

Cheers - #19
 
So Cali, have you seen FPN from cameras that heated up significantly during the course of a hot day? I am willing to err on the side of caution for obvious reasons but it would be great to know about anything specific I should be watching for.

Perhaps my eyes are not as good as I thought but I have never seen any difference between morning shots and afternoon shots even on hot sunny days. Is all this thermal stuff 99% FUD?

Cheers - #19
 
As I know the C-MOS Sensor need an exact operating temperature, thats the reason why the sensor block is mounted on a peltier-element. If you have drastic temperature differences it makes sense to do it. So we do a black shading every shooting day when the cam is ready on set. This is a little bit often I know, but a safe way I think so. Also checking the recorded picture after the cam is rebooted after the shading.
 
Black shade every morning of shoot... but very important after using timelapse setting in the camera, since some "burning" pixels could bring artefacts. The black shading bring every pixel to normal black. There was a post 2 years ago about that...
 
Thanks for reminding me.

Once, I think it's over 2 years ago now, a cameraman with open I eyes saved a day by asking "why is the picture so grainy - we don't have 9db with Red, do we?". We then did a black shading and all was well again. This happened out of nothing.

Never had that issue again.

Every morning black shading the camera makes you better sleep.


Hans
 
I had this exact question, Blair. Thank you for asking it first.

The question is, can a black shading go bad? That is, if properly done, is it possible for a black shading to fail and then not be able to notice it using only the RED's LCD or EVF?

My greatest fear with this camera is that I'll be shooting with the RED and then find that there is something in the image of every shot 1 pixel wide on the 4K file that can't be seen on set through the LCD or EVF. It's never happened to me, but I have heard of this sort of thing happening to others, and it terrifies me. Accordingly, I tend to almost never black shade, as I'm more fearful of something happening during the shading than spontaneously without the shading. Is this just another irrational fear from my deep-seated paranoia of all things technological?

:-)

RED. . . what's the official word on this issue? We're all ears. . . ah. . . eyes.

Stephen
 
So, I did well to do black shading when I noticed problems with IR .. it would be nice to have the official word from the people at RED.
 
Okay, RED Team. . . where are you on this????

The big questions: WHEN do you recommend a black shading? And, just as importantly, can a black shading go awry? And, if so, how would we know on set prior to viewing the bad 4K footage in the studio?

Thanks.

Stephen
 
I think there is no way to harm your camera with a blackshade.

Unlike other cameras, the RED has no memory for the sampled data, which means it can always recognize dead pixels and interpolate them, so we wont see them. At least thats what I know from talking to the technicians from several rental houses, when I had that question.
Therefore I do a blackshade every new shooting day. But there is always the chance of getting vertical stripes or artefacts out of nowhere... But in my case they were always visible on set already. Quick blackshade, everything was fine again :)
 
Always heat your camera to the temperature at which you will be shooting before a black shading. If you cap the lens and turn on FCe, you can get a quick glimpse at whether or not your black shading is appropriate for your camera's given temperature.
 
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