Misc notes

main
Jeff Moe 2023-03-01 16:08:43 -07:00
parent cea7a66c16
commit 116056aa4e
3 changed files with 68 additions and 2 deletions

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@ -24,15 +24,48 @@ Blackmagic Design hardware.
\item [FFMPEG]
\item [Handbrake]
\item [OBS Studio]
\item [Darktable]
\item [Rawtherapee]
\item [Gimp]
\item [Shotcut]
\end{description}
\end{mdframed}
\section{OBS Studio}
Notes.
I have the Blackmagic connected to OBS Studio live via USB to HDMI converter. Before I was re-encoding it and restreaming it to OBS. In this case, I have it on the OBS machine itself, a panda board. So Camera -> HDMI -> USB -> panda -> OBS Studio -> stream out. This way the latency is near realtime-ish too. Works quite well, for the bit I've tested.
This Blackmagic 6K, being able to use any lens, and can stream out 1920x1080, is the best "webcam" setup I've used.
It's also good for a lot of other reasons, of course. But with the image quality detail directly from the sensor, and being able to use "any" lens, is so nice.
This is cam -> hdmi -> usb -> computer -> obs -> restreamer (lan) -> owncast (wan)
\section{Kdenlive}
kdenlive can read Blackmagic 3D LUT files.
Cool, so if something was shot with "Film" setting, I can load it in KDE, apply a LUT filter, load the Blackmagic Film to Video LUT and it all looks magically nice.
Using kdenlive a bit. Happy to see that Blackmagic LUTs work, kind of like magic as name says.
But the LUT conversions provided are all Film to XYZ. So it may be best to shoot in Film mode to begin with, for most flexibility.
As there are four (maybe 5) LUTs available for Film -> Video etc conversion.
On "gamma" one that looks spectactular.
kdenlive can read the Blackmagic .mov files, but not .braw.
\section{Unorganized Notes}
\begin{description}
\item I think the BRAW format is a video HDR format (e.g. takes each photo at multiple exposures).
\item Natron can import BRAW, but requires propietary sdk bits.
\item Audio streaming via HDMI from camera works too.
\item I can tether via the camera and Darktable via USB.
\item But no live pic. Maybe cuz HDMI at same time (?).
\item Ya, USB-C is USB PTP, but no live view.
\item Can't copy images via PTP either. At least it sees it; sort of a start.
\end{description}

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@ -18,7 +18,6 @@ Blackmagic Design.
\input{Cinema6kBody}
\input{Cinema6kScreenshots}
@ -39,6 +38,14 @@ Blackmagic Design.
\item Which I think is to run their proprietary software, but not certain.
\item It eats thru crappy offbrand batteries real fast. Like less than hour, not recording, just poking thru menu.
\item I just pushed the spreadsheet with every Main Menu Settings option, and options for all other physical buttons.
\item Connecting blackmagic via USB-C, creates a /dev/media0 device, not sure what to do with it yet.
\item Power cord in that came with unit works.
\item Trying to think of best way to document a menu tree. Right now I have it in a spreadsheet. That works ok for note taking. Maybe dot.
\item The Blackmagic HDMI out doesn't work with many HDMI devices, whether direct or pass thru.
\item One drawback to this camera is how much power it draws. Using it outside in the cold got less than 10 min of video in less than an hour. This with LCD at 100% because it is very hard to see outside... It has accessories like eyepieces, but these make it even bigger, heavier, and draw more power.
\item I tried using a monopod and video, but it really needs a tripod to keep a good steady image.
\item Zoom can also be increased by changing how much of the sensor to use.
\item So shooting at 1920x1080 gives options to use 6K, 5.7k, or 2.7k area of sensor. Using 2.7k gives most "zoom".
\item It has a lot of options for what to display on LCD and what to display on HDMI, controlled independently.
\end{description}

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@ -36,6 +36,22 @@ Dynamic range.
\end{mdframed}
\section{CinemaDNG}
Notes.
So CinemaDNG is the "open" HDR-like video format. Blackmagic was using it in their earlier cameras.(edited)
But they got a patent threat, so switched to their proprietary .braw, and removed support for CinemaDNG.
Patent threat may have come from "Red" (camera brand).
Or maybe Adobe.
So if you want to take a "HDR"-like photo with a DSLR, you take a picture "normal", then down a step, then up a step, for example.
But this means there can be movement between the shots, even if the camera is programmed to take the shots quickly.
With the Blackmagic internal hardware, all steps (13 of them in fact) are all taken in one shot.
Their old cameras with that feature + CinemaDNG could be a good combo.
Not sure if kdenlive etc can do CinenaDNG though.
Taking a pic with 13 steps all in one shot. wowza, that's pretty cool.
So later, you can just go in post processing and set light how you want, it is very detailed, etc. It would pixelize dark areas that are brightened, or example.
\section{Unorganized Notes}
\begin{description}
@ -60,5 +76,15 @@ Dynamic range.
\item And just better detail overall.
\item Canon has HDR still photo built into the camera. Or on other cameras you can just do 3 (or whatever) then use software such as darkdable to make the final image.
\item The Blackmagic has HDR Still Image, .dng, that rawtherapee can read, but nothng else i tried can.(edited)
\item For use with a libre toolchain, the older generation to the 6K series is better for recording video.
\item Because it can do the CinemaDNG that in theory can by read with free software.
\item Even their cams that at 10+ years old are still quite good, if the hunt isn't for megapixels, but image quality.
\item The v2 series cameras all appear to use the newer proprietary Blackmagic RAW format.
\item The DNG files, both the CinemaDNG and supposedly the braw files, are series of tiff files, or similar. This is how ffmpeg handles them, afaict.
\item The sensor on the Blackmagic can take multiple exposures in a single shot.
\item This makes for a better picture with more detail, better in dark areas, etc. in general.
\item With the .braw format and the proprietary app that reads it, you can access all of these layers.
\item So, for instance, if one part is too blown out, you can select that area and get a darker version of it, as taken by the camera, not kludge later with an algorithm. So the picture is much better.
\item With kdenlive, iit can only read the .mov format of Blackmagic. So there is no way to access these other exposure layers.
\end{description}