Announcement

Collapse
No announcement yet.

Mini 4.6k FW 4.2

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • #31
    Originally posted by jonesyjones View Post
    Tim Schumann from Blackmagic on another forum said "Black calibration shouldn't be required on a frequent basis but should be carried out if you feel your black levels need resetting. This is not something you should need to carry out on a daily or even weekly basis."
    Re-Calibrate if the operating temperature of the camera changes in temp of 10 degrees or greater....temp is more important than time.

    Ohh yes, almost forgot...ignore the fanboys and cheer squad as they have cost BMD an absolute fortune in sales through denials, which as we know is a river in Africa.

    Imagine how many cameras BMD would have sold, if they listened to feedback and chased down the bugs from day one !!
    Last edited by AndrewDeme; 12-23-2016, 07:43 PM.
    Lotsa Zeon thingos with thousands of cute cores...enough is never enough

    www.andrewdeme.com
    http://www.youtube.com/andrewdeme
    www.facebook.com/andrewdeme
    http://www.linkedin.com/in/andrewdeme

    (I reserve the right to edit, modify or delete any content I create anywhere at anytime...it probably wasn't that good anyway)

    Comment


    • #32
      Yes true, however, BM Ursa and the Irsa Mini have a fairly efficient cooling system, and while they are operating after initial warm up, they keep their temp fairly constant. But, as you indicstrd, if you go from a room temp situation to a cool or cold outdoor temp, then a Blsck Calibration might be a good idea.
      Cheers

      Comment


      • #33
        Originally posted by Denny Smith View Post
        Yes true, however, BM Ursa and the Irsa Mini have a fairly efficient cooling system, and while they are operating after initial warm up, they keep their temp fairly constant. But, as you indicstrd, if you go from a room temp situation to a cool or cold outdoor temp, then a Blsck Calibration might be a good idea.
        Cheers
        These cooling systems are not say like my Nest Thermostat and accurate to .1 degree......they instead operate their cooling on a 'power level', which is why changes in ambient temperature create the need to re-calibrate.
        Lotsa Zeon thingos with thousands of cute cores...enough is never enough

        www.andrewdeme.com
        http://www.youtube.com/andrewdeme
        www.facebook.com/andrewdeme
        http://www.linkedin.com/in/andrewdeme

        (I reserve the right to edit, modify or delete any content I create anywhere at anytime...it probably wasn't that good anyway)

        Comment


        • #34
          No comment
          Cheers
          Last edited by Denny Smith; 12-24-2016, 05:57 PM.

          Comment


          • #35
            Gee, a lot of sanctimonious experts here on black balance in Blackmagic cameras.

            Have a read again of what Tim Schuman, the Ursa Mini product manager said...

            Blackmagic, like Arriflex, use solid state cooling (or even heating) to maintain a very stable and very consistent operating temperature.

            Blackshading is very sensitive to thermal changes which is why you have so much variation on cameras that don't do active cooling like RED or Sony.

            RED are fan only based. They spin the fans faster to draw more air, sometimes to the detriment of sound even. On an Alexa, the fan's spin at a constant rate to draw heat away. Like on an Ursa. The fan's aren't what is cooling the camera, the peltier or solid state refrigerator is.

            Both Alexa and Blackmagic use a peltier chip and in the Alexa this maintains a consistent operating temperature range within + or - 0.5 deg c no matter what the ambient temperature is. The internal temperature is maintained as the external temp changes.

            If you can maintain the same temperature no matter what the ambient temperature is, then you can also do very very consistent black performance / noise performance.

            However, what seems to happen specifically in the case of the Ursa Mini 4.6k sensor is that after some time the initial calibration drifts. The raised blue channel or the mismatched green channels (cross hatching) then cause other issues.

            So no, it's not like a RED where you have to do the blackshading after an ambient temperature change. No its not like a RED cause it's done in a a few seconds.

            No. It's not like a RED. It's like an Alexa.

            Hopefully Blackmagic will technically explain this instead of me. But here's what's in the Alexa manual.

            "The ALEV III sensor has a horizontal pixel count of 3.5K resulting in true 2K resolution. It covers the full Super-35 format and it provides a latitude of 14 stops and a base sensitivity of 800 ASA.

            The sensor temperature is kept stable by a Peltier element to ensure optimum image quality under all operating conditions."

            And...

            "ALEXA has a Peltier element that keeps the image sensor at a stable temperature. This is important to achieve constant image quality. Under some occasions, the camera might not be able to keep this temperature, or it might take some time to reach the correct level. This can be the case right after booting, or with very hot or cold ambient temperatures.

            A red temperature icon indicates that the sensor temperature is too far off to guarantee a high image quality, while a white temperature icon indicates that image quality is still in the (very high set) quality limits required by ARRI. "

            Tropical mode is like having a separate high ambient temp calibration. That's why they say you shouldn't leave it in tropical mode all the time. Urban mythology is that it spins the fan faster. It doesn't. It sets the internal sensor temp at a higher maintenance number. From memory it's 35 deg c in normal and 40 in tropical. This is not ambient temp, this is internal sensor temp independent of the ambient temperature. Pretty sure it's in the manual if you want to look it up.

            Having two operating temps means two sets of blackshading.

            So again, look at what's Tim Schuman says and not use our understanding of blackshading on a RED to inform what happens on a camera that uses a totally different approach to sensor cooling.

            JB

            (edit - I've always laughed when a common problem listed on review sites like BHl is that Blackmagic cameras overheat. I've never seen it happen ever. The media will melt before the camera does.)

            Comment


            • #36
              Originally posted by John Brawley View Post
              Gee, a lot of sanctimonious experts here on black balance in Blackmagic cameras.

              Have a read again of what Tim Schuman, the Ursa Mini product manager said...

              Blackmagic, like Arriflex, use solid state cooling (or even heating) to maintain a very stable and very consistent operating temperature.

              Blackshading is very sensitive to thermal changes which is why you have so much variation on cameras that don't do active cooling like RED or Sony.

              RED are fan only based. They spin the fans faster to draw more air, sometimes to the detriment of sound even. On an Alexa, the fan's spin at a constant rate to draw heat away. Like on an Ursa. The fan's aren't what is cooling the camera, the peltier or solid state refrigerator is.

              Both Alexa and Blackmagic use a peltier chip and in the Alexa this maintains a consistent operating temperature range within + or - 0.5 deg c no matter what the ambient temperature is. The internal temperature is maintained as the external temp changes.

              If you can maintain the same temperature no matter what the ambient temperature is, then you can also do very very consistent black performance / noise performance.

              However, what seems to happen specifically in the case of the Ursa Mini 4.6k sensor is that after some time the initial calibration drifts. The raised blue channel or the mismatched green channels (cross hatching) then cause other issues.

              So no, it's not like a RED where you have to do the blackshading after an ambient temperature change. No its not like a RED cause it's done in a a few seconds.

              No. It's not like a RED. It's like an Alexa.

              Hopefully Blackmagic will technically explain this instead of me. But here's what's in the Alexa manual.

              "The ALEV III sensor has a horizontal pixel count of 3.5K resulting in true 2K resolution. It covers the full Super-35 format and it provides a latitude of 14 stops and a base sensitivity of 800 ASA.

              The sensor temperature is kept stable by a Peltier element to ensure optimum image quality under all operating conditions."

              And...

              "ALEXA has a Peltier element that keeps the image sensor at a stable temperature. This is important to achieve constant image quality. Under some occasions, the camera might not be able to keep this temperature, or it might take some time to reach the correct level. This can be the case right after booting, or with very hot or cold ambient temperatures.

              A red temperature icon indicates that the sensor temperature is too far off to guarantee a high image quality, while a white temperature icon indicates that image quality is still in the (very high set) quality limits required by ARRI. "

              Tropical mode is like having a separate high ambient temp calibration. That's why they say you shouldn't leave it in tropical mode all the time. Urban mythology is that it spins the fan faster. It doesn't. It sets the internal sensor temp at a higher maintenance number. From memory it's 35 deg c in normal and 40 in tropical. This is not ambient temp, this is internal sensor temp independent of the ambient temperature. Pretty sure it's in the manual if you want to look it up.

              Having two operating temps means two sets of blackshading.

              So again, look at what's Tim Schuman says and not use our understanding of blackshading on a RED to inform what happens on a camera that uses a totally different approach to sensor cooling.

              JB

              (edit - I've always laughed when a common problem listed on review sites like BHl is that Blackmagic cameras overheat. I've never seen it happen ever. The media will melt before the camera does.)
              Toxic criticism in the first sentence and off we go....marketing 101....go figure !

              If only I had some idea of what I was talking about....especially in relation to those ever so complicated solid state heat pumps...where are those high school students when you need them ?

              On another note, if only BMD considered the more consistent and stable water cooling option...ahh, that is for another post...but no doubt a 'cheer squad member' will need to approve first as the image has always been perfect, regardless of the number of times BMD have implemented fixes.
              Last edited by AndrewDeme; 12-24-2016, 02:56 AM.
              Lotsa Zeon thingos with thousands of cute cores...enough is never enough

              www.andrewdeme.com
              http://www.youtube.com/andrewdeme
              www.facebook.com/andrewdeme
              http://www.linkedin.com/in/andrewdeme

              (I reserve the right to edit, modify or delete any content I create anywhere at anytime...it probably wasn't that good anyway)

              Comment


              • #37
                Peltier coolers are better than water coolers, at the actual task of cooling. However they use more energy. They are the preferred option for multi million dollar telescope sensors, high end astrophotography, and all those fancy Arri Alexas. If it's what top notch imaging scientists use for the most expensive imagers in the world, mainly because of it's accuracy and speed to adapt, we should all be very happy that Balckmagic use them too. I didn't, but am very happy to hear it.

                Thanks John
                James Iain Barber
                Editor, writer, director, shooter, yadda yadda.

                Comment


                • #38
                  Originally posted by John Brawley View Post

                  Have a read again of what Tim Schuman, the Ursa Mini product manager said...
                  )
                  Thanks John, your posts are always informative/ educational to me.
                  karlkimdp.com

                  Comment


                  • #39
                    Originally posted by JIB View Post
                    Peltier coolers are better than water coolers, at the actual task of cooling. However they use more energy. They are the preferred option for multi million dollar telescope sensors, high end astrophotography, and all those fancy Arri Alexas. If it's what top notch imaging scientists use for the most expensive imagers in the world, mainly because of it's accuracy and speed to adapt, we should all be very happy that Balckmagic use them too. I didn't, but am very happy to hear it.

                    Thanks John
                    There is a lot to be gained from well designed cooling and of course calibration...if curious, just borrow a FLIR Camera and point it down the throat of any camera and you will get the idea.

                    As for cooling, well it is a black art :-

                    http://www.andor.com/learning-academ...oling-to-scmos
                    Lotsa Zeon thingos with thousands of cute cores...enough is never enough

                    www.andrewdeme.com
                    http://www.youtube.com/andrewdeme
                    www.facebook.com/andrewdeme
                    http://www.linkedin.com/in/andrewdeme

                    (I reserve the right to edit, modify or delete any content I create anywhere at anytime...it probably wasn't that good anyway)

                    Comment


                    • #40
                      Originally posted by AndrewDeme View Post
                      Toxic criticism in the first sentence and off we go....marketing 101....go figure !
                      He called a spade a spade. Frankly, if you're so above it then it aught to behoove you to have a level headed response.

                      Comment


                      • #41
                        Originally posted by Alex.Mitchell View Post
                        He called a spade a spade. Frankly, if you're so above it then it aught to behoove you to have a level headed response.
                        Merry Christmas....
                        Lotsa Zeon thingos with thousands of cute cores...enough is never enough

                        www.andrewdeme.com
                        http://www.youtube.com/andrewdeme
                        www.facebook.com/andrewdeme
                        http://www.linkedin.com/in/andrewdeme

                        (I reserve the right to edit, modify or delete any content I create anywhere at anytime...it probably wasn't that good anyway)

                        Comment


                        • #42
                          Just as an experiment, I left my camera running for two days in my office that was a bit cool but comfortable! Didn't notice anything different on the screen. The BM Viewfinder was warm, but nothing to be concerned about. There was some slightly detectable warmth rising from the top vents on the URSA Mini 4.6K. It was quite stable, probably all very similar to what it would be if I had the camera running for an hour.

                          Comment


                          • #43
                            Originally posted by rick.lang View Post
                            Just as an experiment, I left my camera running for two days in my office that was a bit cool but comfortable! Didn't notice anything different on the screen. The BM Viewfinder was warm, but nothing to be concerned about. There was some slightly detectable warmth rising from the top vents on the URSA Mini 4.6K. It was quite stable, probably all very similar to what it would be if I had the camera running for an hour.

                            The warmer it gets the warmer it gets...is how Peltier Coolers work.
                            Lotsa Zeon thingos with thousands of cute cores...enough is never enough

                            www.andrewdeme.com
                            http://www.youtube.com/andrewdeme
                            www.facebook.com/andrewdeme
                            http://www.linkedin.com/in/andrewdeme

                            (I reserve the right to edit, modify or delete any content I create anywhere at anytime...it probably wasn't that good anyway)

                            Comment


                            • #44
                              I was able to use some of a suggestion from another forum and finally able to perform a black shade calibration that got it to show ISO 1600 to be as equally black as all the other ISOs in complete darkness.
                              https://forum.blackmagicdesign.com/v...=55468#p319206

                              I tried the above wih lens cap on the lens and it was not successful so lens cap on the body is needed.
                              I also have to set it to ISO 1600. I know others say about ISO does not matter when performing black shading and I cant offer any explanation why it should.

                              You may want to check. Place a cap on your camera body and watch the LCD screen in a very dark room. Then compare each ISO setting and see if the screen gets brighter especially ISO 1600 if there are FPN?
                              I finally got mine to look equally dark in all the ISOs. Thats said I have yet to see much different in real world use but this may show up in more critical comparison.

                              Comment

                              Working...
                              X