Thread: BLACK SHADING For Dummies & Experts

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  1. #11  
    Senior Member Doug Beatty's Avatar
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    Quote Originally Posted by Nick Pasquariello View Post
    I have a followup question. On a recent shoot, an AC and I were looking at two Epics, and seeing that the temp was yellow on one (as well as a full 5 degrees Celsius different than the other, despite having had more than an hour of warm-up time each, and same fan settings), decided to blackshade. (Core temp difference could have been due to differing firmware, the cooler one was running the latest v4 stable release, and the warmer one was running the latest v5. [Oh, and for the curious, blackshadeing time between the two firmwares took exactly the same amount of time])

    Anyway, the question: during the blackshade process, the fans run high, and as the camera is shading, the core and sensor temps cooled down considerably. If the sensor is cooling as it's blackshading, (and I'm talking 5-8 degrees Celsius here), is it really getting a good read? And is the shade calibration map based on . . . the temp at the start? Middle? Seeing as how we were shooting interviews, with low fans, I can't imagine that a calibration map while fan is BLASTING on high would be much use 15 minutes into a shot with fans on absolutely minimal . . .
    I noticed the exact same thing when setting my fans to APQR. I have the core temp target set to 70 and fan speed at 25. After ten minutes the camera tends to hover around 40/70. Rolling a 2-3 minute clip, the sensor temp creeps up to 43-44 and I get the yellow T+ warning. Cutting brings the temp back down to 40.

    I tried rolling for 5 minutes to let the sensor heat up and then immediately blackshading, but the fans cooled the sensor back down after erasing the first pass and the new calibration was basically the same as the original.

    I don't think it's possible to record at 25% for more than 2 minutes on the V1 fans without getting a warning, but I'd rather stay in the yellow than up the fan speed during takes.
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  2. #12  
    Senior Member Ketch Rossi's Avatar
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    Yes great post and very detailed explanation, good job Mark!!

    Only thing I like to add is that when doing a Black Shading, while this is to be done more so specifically to the need of having the camera record at location temperature, hence the need to Black Shade at given temperature is a must, however one must not confuse the temperature SURROUNDING the camera, with the CAMERA actual temperature in that particular surrounding temperature int hat given environment...

    Also it is most important that Black Shading is done, NOT only in suggestion to Mark's great post, were you would run the camera for several minutes while recording "NOTHING" just so to favorably reach the optimal camera temperature, before Black Shading, but it is also VERY important that if shooing the entire scene at MAX Frame Rate for that given resolution, which for me it is easy... ALWAYS MAX, was 5K now 6K... So if you are doing the same or what ever rez you choose but are shooting max FPS, then set the camera to this FR first, then run a quick 10 minutes recording at that speed...

    WHY?

    Because recording at such HIGH frame rate, runs the camera hotter... So if shooting at that FR, then you better also Black Shade in accounting for that temperature reached by the camera during the shoot.

    Then when done shooting HFR, let the camera rest a few, then repeat the Black Shade after recording 10 minutes of the new probably 24p recording FR, as the camera will run cooler.

    Black Shading now is so much faster, even on Dragon, and there is NO excuse to not know what you are supposed to do, and not taking the time to do it, Film cameras used to be and still are a HUGE pain in the rear to set up and run, Alexa same thing, so why not take few extra minutes to do things right for the beets Image results?


    BTW, the new Fan Kit do not make a difference even with DRAGON... They make a BIG difference!!


    One last thing that gets brought out a lot as well is "How do I know when do I need to do a Black Shading"?

    And the answer is simple, and it has been said many times thru the years, every time you bring the camera in to a very different OPERATING TEMPERATURE settings, which is a combination of LOCATION TEMPERATURE and CAMERA running temperature, you should do a BLACK SHADING.

    I do this even when on the same location all day, as some times when shooting Sunrise, and then Sunset, the temperature can change by a LOT, and while at times depending on time of year and location, it does not, when it does I keep an eye on it, and BLACK SHADE accordingly.

    Again, keeping in mind all above said by Mark and myself, and apply accordingly including the Frame Rate and all camera settings.
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  3. #13  
    Senior Member Karim_Nassar's Avatar
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    very informative thanks a lot
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  4. #14  
    Quote Originally Posted by KETCH ROSSi View Post

    One last thing that gets brought out a lot as well is "How do I know when do I need to do a Black Shading"?

    And the answer is simple, and it has been said many times thru the years, every time you bring the camera in to a very different OPERATING TEMPERATURE settings, which is a combination of LOCATION TEMPERATURE and CAMERA running temperature, you should do a BLACK SHADING.

    I do this even when on the same location all day, as some times when shooting Sunrise, and then Sunset, the temperature can change by a LOT, and while at times depending on time of year and location, it does not, when it does I keep an eye on it, and BLACK SHADE accordingly.
    But - as much as LOCATION TEMPERATURE can and will effect your your Core Tmp and ultimately your Sensor Temp - it does not ALWAYS. I've jumped between environments with a difference of 20 degrees F - and maintained Core and Sensor Temp - and MOST of the time I can just make a minor adjustment to the target temp of the fsn setting and hit my CalMap temp.

    There is no penatly for black shading more than you need to - except the 13 minutes (Dragon) that you loose - but don't think just because you move from the sound stage to outside and it's 20 degrees cooler that you need to re-blackshade. Make sure you understand your CAL: T/E meter detailed in my first post on this thread and also on the DSMC Operations Manual that too many people fail to read - and pay a little attention to it. If you understand all of thses things - you might find that you need to black shade less often than you currently do.

    The new fans are key to making all of this work easily and efficiently. I find it is VERY easy now to maintain and control core temp and fan loudness if you spend a little time and get to know your fan settings.

    The CAL: T/E indicator is going to tell you - and if you look at the filename of your current CalMap - you will know what temp it was created at as well.

    Ketch makes a good point with his suggestion of setting the camera to the primary framerate you think you will shoot at as higher framerates or HDRX will increase Core Temp faster - but remember - the blackshade does not care about what framerate you shoot at - only the EXPOSURE TIME (shutter speed) and the SENSOR TEMP (effeted by the CORE TEMP - which you control with FAN SETTINGS).
    Last edited by Mark L. Pederson; 01-23-2014 at 04:28 AM.
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  5. #15  
    Senior Member Ketch Rossi's Avatar
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    Correct Mark... ;)
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  6. #16  
    Senior Member Jason Kraynek's Avatar
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    anyone have the best practice for covering the camera w/o blocking the fans and spilling the light from the lcd while black shading? Last night i hat a winter hat over the lcd- I'm sure theres a better way. (though it was a cool hat and all)
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  7. #17  
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    thanks!!!
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  8. #18  
    Senior Member D Fuller's Avatar
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    Quote Originally Posted by Mark L. Pederson View Post
    Okay … there’s WAY too much confusion and incorrect information floating around about Black Shading. Today I even read a post on CML by someone who was talking about a recent Dragon shoot where the camera was warning that “it was going to overheat” - when in fact - it was just the CAL T/E indicator was just telling him that his sensor temp was slightly different than the temp the camera was blackshaded at!! Oh my.

    I'm 100% convinced that lots of folks shooting RED are shooting lots of footage with a non-optimal back shade and many don't even know it. Let’s end this madness now.

    Here’s a guide to Black Shading - OFFHOLLYWOOD style.




    Let’s start by focusing on the TWO factors that effect a CalMap - beyond the obvious fact that a CalMap is specific to the actual individual sensor that you calibrate - in other words you would not load on CalMap made on one Epic into a different Epic.

    #1: EXPOSURE TIME (aka Shutter Speed)
    #2: SENSOR TEMP

    When you create a CalMap by blackshading - you can save the file into the camera and/or onto the SSD so that you can copy it to a hard drive and save it. Currently, the latest firmware only lets you hold ONE user created CalMap in addition to the factory default inside the camera. But you can create and save as many CalMaps as you want with different Exposure Times and Sensor Temps onto SSDs - copy to hard drive - copy back to an SSD and load into the camera. Hopefully - soon - we will be able to hold 4 or so CalMaps so that we could switch to another one instantly - wouldn't that be bad ass? :)

    When you look at actual CapMap file - the naming convention works as follows:

    example: 48_45C_20140108080645

    The first digits are the EXPOSURE TIME aka Shutter Speed - in this example 48 for 1/48th of a second. Forget about “Eqivalent Degrees (180 deg., etc.) since that is calculated based on framerate and shutter speed. This is one reason I avoid Equivalent Degrees and like to keep my GUI on Shutter Speed fractions of second as they are absolute.

    The second digits are the SENSOR TEMP in celsius. In this example 45C.

    The next digits in the filename are the DATE (year/month/day) - 2014/1/8 in this example.

    The next digits in the filename are (HH/MM/SS) relating to the 24 hour clock in the camera just to differentiate equivalent calibrations at different times.

    Your back shade CalMap file only cares about Exposure Time - it doesn’t actually care at all about Frame Rates. Sure, when you increase or decrease frame rates you can be forced to increase or decrease your Shutter Speed - but if you black shade with camera at 1/60th of second at 23.98fps with Sensor Temp of 40C - it would be the exact same CalMap as if you black shaded at 1/60th of second at 50fps with Sensor Temp of 40C and the filenames of both CalMaps would start with “60_40C_” - so ... it's all about Shutter Speed and Sensor Temp.

    On the GUI you will see “TEMP: XX/YY” where XX = Sensor Temp and YY = Core Temp.

    Most of the time the Core Temp will be warmer than the Sensor Temp - as the Sensor is closer to the fan/cooling chamber that the Core (guts) of the camera where the processing happens.

    The Sensor Temp is effected by the Core Temp - Core Temp gets warmer = Sensor Temp gets warmer, Core Temp gets cooler = Sensor Temp gets cooler. Think of it as the Sensor Temp “reacts” to the Core Temp.

    Your FAN SETTINGS control the CORE TEMP. So, your “Target Temp” you can set in Adaptive and Adaptive Quiet Record is the Core Temp you want to the camera to level off at and stay at. Adaptive and Adaptive Quiet Record, with the new updated fans, are amazingly fast and efficient at maintaining a target core temp. I stay away from AUTO and MANUAL fan modes.

    The "CAL: T/E" indicator just below the TEMP indicator on the GUI displays the relative change in the temp and exposure times to currently loaded CalMap. The T (Sensor Temp) and the E (Exposure Time) are GREEN when you are “all good”. If one turns Yellow there’s a slight change - if one turns Red there’s a significant change. A + or - will appear to indicate if the Temp or Exposure has increased or decreased.

    DO NOT PANIC if your T turns Yellow during a shot. You are most likely totally fine. However, I try to stay in the green and you should too - and specifically if you are shooting low light - where you might fight the noise floor - you want that Sensor Temp on the money with your CalMap if you want the cleanest image off the sensor. Think of Yellow as "pay attention" and consider a fan adjustment, shutter spped adjustment - or ... re blackshading or loading a pre-created CalMap that more closely matches the T or E.

    If you make a slight adjustment to your TARGET TEMP in your fan settings - you typically will see the Core Temp quickly adjust and the Sensor Temp following. So, as opposed to re-calibrating if your T turns Yellow to get Green on the T in the CAL: T/E indicator - adjust your TARGET TEMP.

    You will see that you can swing the Exposure Time (shutter speed) quite a bit without getting a Yellow warning. But bottom line - that CAL: T/E indicator is gonna let you know when you are pushing it a little - or pushing it too much.

    ALWAYS black shade when you update or re-install firmware and throw out any saved CalMaps you have if you archived any.

    Note that with Dragon especially, it takes a bit of time to warm up the camera. So, best practice is to get your camera crew (or yourself) to power up the camera as fast as possible - ideally while they are building it - so it’s reached it’s Core Temp target and your Cal: T/E gives you all green before you need to roll. If I’m in pinch - I stick in a mag and just let the camera roll non-stop for a couple minutes - I find that it brings the camera up to temp faster. Then I just re-format the card.

    You can pre-create CalMaps for different Sensor Temps by adjusting the Target Temp in the fan settings - let the Core Temp settle to the Target Temp and create the CalMap storing it to the SSD. Then increase or decrease the Target Temp - rinse and repeat. This way, you can have a few CalMaps at different temps and/or extreme shutter speeds so you can load them into the camera from an SSD in a second as opposed to re-calibrating for 13 minutes.

    I hope some of you find this post helpful.
    Mark, you're a mod. Please make this a sticky!
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  9. #19  
    Quote Originally Posted by Jason Kraynek View Post
    anyone have the best practice for covering the camera w/o blocking the fans and spilling the light from the lcd while black shading? Last night i hat a winter hat over the lcd- I'm sure theres a better way. (though it was a cool hat and all)
    Best practice is to remove the lens and put the metal body cap on - that said - many times folks will blackshade with the lens on - so close the aperature - put on a lens cap - and ideally throw a heavy piece of black duvatine (you should keep a 3' square in your kit anyway) over the lens/lens cap because SOME plastic lens caps are actually NOT 100% opaque and some light gets in and your CamMap will be wonky.

    You don't need/want to cover the camera! Just stop ALL light from coming into the sensor.
    Last edited by Mark L. Pederson; 01-23-2014 at 07:18 AM.
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  10. #20  
    Senior Member Jason Kraynek's Avatar
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    Quote Originally Posted by Mark L. Pederson View Post
    Best practice is to remove the lens and put the metal body cap on - that said - many times folks will blackshade with the lens on - so close the aperature - put on a lens cap - and ideally throw a heavy piece of black duvatine (you should keep a 3' square in your kit anyway) over the lens/lens cap because SOME plastic lens caps are actually NOT 100% opaque and some light gets in and your CamMap will we wonky.

    You don't need/want to cover the camera! Just stop ALL light from coming into the sensor.
    good idea. i have a Canon TI mount and the cap is plastic so throwing a spotted down prime on with a cover would make the most sense. thanks sir
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