Posts Tagged ‘blackmagic

17
Apr
15

Blackmagic cameras stuck / dead pixels problem: no solution offered!

Blackmagic Design has launched and promotes it’s 4K “Production Camera” as a professional camera for professional cinema production. That you can’t expect the world from a 3K US$ camera; i totally agree, but selling a camera under that flag, with an inferior image sensor is – at the least –  an insult to professional filmmakers and everyone else who has spent his or her savings on the “BMPC”.

What is the problem here? It’s simple… Every BMPC has clusters of dead or stuck pixels, that show up as specks on the image. Some cameras have a few, but EVERY camera i personally tested had dozens of stuck pixels.The pixels can have any shade of gray or appear colored. The intensity of stuck pixels can be anything from black to full 100% IRE.

All BMPCs i’ve either owned, rented or lent had a few defective pixels with an intensity that made them show up in the picture, even if well exposed – e.g. full daylight and at the standard 400ISO. Stuck pixels like that will be visible in lower-mid ranges of the image. Because those pixels have a fixed position: the larger the screen, the more obvious they become in moving images.

I have recently screened a test DCP at a local cinema, where the stuck pixels showed up as little holes in the projection screen. Around four of the stuck pixels in my BMPC show up in low-mid skintones (approx. 30-50% gray) and are easily recognizable on any monitor or TV set.

Is the BMPC the only camera that has a sensor behaving like this? No! Even the Alexa and the Red Epic Dragon have many stuck or dead pixels. Why don’t we see them? Because these cameras use a technique called Black Shading or Defective Pixel Mapping, where a dark image is analyzed and misbehaving pixels are marked as “don’t show this one, copy it’s values from a neighbor”. Blackmagic Design cameras are lacking this option, or – at least – it’s not working well.

Blackmagic Design is not very supportive, does not recognize the problem and is very secretive about the whole subject.

Claims are denied, questions are not answered. If you inquire about pixel mapping in their cameras, or ask when such pixel mapping will be incorporated in an upcoming firmware release, you’ll get either ignored or receive a standard answer, along the lines of “send us the camera and we will investigate” – conveniently avoiding a decent answer.

People who have sent their cameras in, did either got their camera returned in the exact same condition or received a new camera that had the same problem, only with the same kind of stuck pixels in different places.

Some people report that the stuck pixels get worse or less worse over time, when the sensor heats up during use. That makes things even worse and makes the sensor totally deserves the title “loose canon“.

I was planning to shoot a documentary feature with the BMPC. I bought the camera in november 2014. Since then there was not a single firmware update that addressed the BMPC. So there is no solution offered by Blackmagic Design and i find that extremely disappointing AND has made me decide NOT to use the BMPC. Period.

Black Magic has a whole range of automatic answer emails present if you complain about this issue. One of their standard defenses is claiming that the have told you that the BMPC is not a low-light camera. First of all, nobody told me, (on the contrary: during IBC 2014 the BMPC was hyped to me as a true Scarlet replacement – LOL) but this has nothing to do with it. Defective pixels appear in well lit 400ISO pictures. ALWAYS. Each picture – even with minimal contrast – has gradients from dark to light, right? So does Black Magic Design mean that i should only shoot bright scenes and objects? Don’t be ridiculous!

Dear Black Magic Design, you sold me a “production camera” that is lacking basic pixel mapping in it’s software. Even low budget and outdated cameras such as the Panasonic GH2 have this functionality.
Please, either refund my camera or fix the issue. Stop hiding behind default excuses and requesting investigation, because we all already know what the problem is.

If you Google on the subject, or browse Youtube, Vimeo or their own BM forum, you will find A LOT of unhappy BMPC owners with the same problem or worse (even though Black Magic Design claims the problem doesn’t exist).

DO NOT believe any article that claims to have a method of removing the stuck pixels! Some people claim that rolling back and re-installing firmware versions fix the problem. It’s nonsense and probably has to do with the heating up of the sensor during the “fixing ” process.

Before you all go out buying the new Blackmagic Design Ursa camera (4K sensor), you will encounter the same problem. The 4k version of the camera (the only one you can probably afford) has the same sensor and the same problem. Ursa users are equally flabbergasted that their cameras have stuck pixels and no decent pixel mapping; and that for a camera that sells for double the price of a BMPC!

To conclude… I am a cameraman for around thirty years now and i have never been more disappointed about a camera, and i have owned quite a few! It’s the arrogance and total lack of support from the manufacturer that pisses me off. Calling this device a Production Camera is absolutely bollocks

I hope Blackmagic Design comes up with a solution between now and a month or two max, and restore my faith in their product(s). I was informed about the new upcoming Ursa models long before anyone else, but i still decided to give the BMPC a change last november, because i have a job to do! I was planning on buying an Ursa later this year, but the experience with the BMPC has changed my mind – for now…

Martin.

Tags: #bmpc #bmc4k #blackmagic #ursa @BlackMagic_BMD #pixels

(Ps. this is a general example of the stuck pixels problem in the BMPC. Footage is not my own. I have lost the energy and appetite to do more tests and publish my own findings here for now.)

General example of stuck pixels General example of stuck pixels

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25
Oct
14

I downgraded from Red Scarlet MX to Blackmagic Production Camera, but it feels like an upgrade!

Martin Beek https://livecrew.nl I’ve thought long and hard about my next move, camera-wise. My Red Scarlet MX was eligible for upgrading to an Epic for 9000US$, or upgrading to a Scarlet Dragon for 9500US$. I paid a small fortune for my Scarlet and adding another 9 grand meant that i could’ve better bought an Epic in the first place. IMHO, not much of a deal or “gesture” to Scarlet owners.

I decided eventually to sell the Scarlet now it’s still worth a few bucks. Emphasizing on “a few”.
I had to let it go a few weeks ago for 7200 euros including a cage, Redmote, two 64gb SSDs, 5″ LCD, sideSSD, etc.; the complete scarlet package plus tophandle and cage. That amount of money is peanuts, but hey, you know that it devaluates starting day one.

I decided to “downgrade” to a 3000US$ Blackmagic production camera, forMartin Beek https://livecrew.nl https://livecrew.nl/martinbeek having a camera around the place and have something to play with during the fall and winter. Bought myself a great Sigma 18-35 1.8 zoom and a cage with handles plus three 500GB SSDs. Still had enough money left to buy some extra audio gear, Vmount batteries and pay a few months of mortgage for the house! 😉

I thought i’d bought Martin’s next plaything and considered it to be a downgrade just to please my desire to own a camera.
I was almost shocked to learn that the 3000$ silly looking package produced way sharper and detailed images that my Red scarlet ever did! It has roughly the same dynamic range and s/n ratio, but seems to reveal much more micro-detail instead of bags of noise when blowing images up to 200%. VERY VERY IMPRESSIVE!

https://livecrew.nl/martinbeek Martin Beek https://livecrew.nl I shoot 24p exclusively in 4K on any camera – i rent highspeed cameras when i need them. So the Blackmagic production camera is a gift from heaven to indie filmmakers. For the price of renting a Red (don’t you ever think of buying one!) you can buy two or three BMPCs !!!  And, just to make this clear, i am not paid of sponsored by BM to tell you this! 😉

I’ll definitely shoot my next feature on multiple BMPCs, i swear!

Cons?

  • It needs bags of light (so buy a speedbooster or <=1.8 lens)
  • 400 ASA natively: use a ND filter and don’t switch to 200ASA (limiting DR)
  • 800 ASA is too noisy, just stick with the 400 ASA and crank the exposure up in post; it’ll look great!
  • No white balance. Just a range of Kelvins to choose from. Shoot a color card or WB card and adjust in post.
  • Internal battery wears down just below one hour. Buy one medium sized Vmount battery and you’re good for hours.
  • The BM CINEMADNG Raw codec is HUGE and will slurp your precious SSD gigabytes before you know it.
    BM HAS to device a way to adjust the compression level of the codec or come-up with something new, because this data-rate is outrageous. Recording just 12 minutes on a 500GB ssd is something i can NOT live with. Imagine shooting a feature film with this… My storage and backup costs would go through the roof! The Red Scarlet recorded 34 minutes of full 4K with low compression (1:6) on a 64GB ssd !

DSC_0133Pros?

  • Lightweight form factor, though very well build metal design – feels solid
  • Record prores and raw (Cinema DNG)
  • Super 35mm large sensor, great filmic shallow DOF with the right lenses
  • Comes with a fully licensed version of DaVinci Resolve (including dongle)!
  • Very nice skin color representation and silky smooth light transitions (just a personal / subjective opinion)
  • Low (audible) noise
  • full Canon EF lens communication and LANC (BeBop lanc controller will even control focus)
  • 4K SDI out
  • 12-35 volt input, so hookup any juice that doesn’t kill you 😉
  • Easy operation, easy menu’s

DSC_0130

My next project… Taking a scene shot with my Scarlet, and repeating it with the same lens on the same location and under the same lighting conditions and show you the difference!
Shooting some hi-contrast winter footage with the BMPC!

Cheers!
Martin.

27
Apr
11

GH2 HDMI recording AviSynth script update

Terrific news from DVXUser member Ralph B!

This is an update of the advanced script to convert footage recorded from the Panasonic GH2 HDMI output, using AviSynth, as posted on April 24, 2011, and it superceeds the original script. (see below for more info)
ADVANCED SCRIPT TO PROCESS 1080 24P FOOTAGE:

 
#change paths to point to your plugins:
LoadPlugin("C:\Program Files\AviSynth 2.5\plugins\TIVTC.dll")
LoadPlugin("C:\Program Files\AviSynth 2.5\plugins\FDecimate.dll")
LoadPlugin("C:\Program Files\AviSynth 2.5\plugins\mvtools2.dll")
#optional for Prores MOVs, uncomment if necessary:
#LoadPlugin("C:\Program Files\AviSynth 2.5\plugins\qtinput.dll")

# for AVI:
avisource("Your HDMI movie.avi")
# OR for ProRes movies, use (and uncomment) the following line and remove the avisource line above
# qtinput("Your HDMI movie.mov") 

function filldrops (clip c)
{
  even = c
  super_even=MSuper(even,pel=2)
  vfe=manalyse(super_even,truemotion=true,isb=false,delta=1)
  vbe=manalyse(super_even,truemotion=true,isb=true,delta=1)
  filldrops_e = mflowinter(even,super_even,vbe,vfe,time=50)
  ConditionalFilter(even, filldrops_e, even, "YDifferenceFromPrevious()", "lessthan", "1.3")
}

# 3:2 Pulldown Removal
AssumeTFF()
trim(1,0)
TFM(mchroma=false)
FDecimate(threshold=0.5)
AssumeFPS(24000,1001)

# Chroma Fix
FixBrokenChromaUpsampling()
converttoyv12()

# Fix Residual Duplicates
filldrops()

#Audio Delay
delayaudio(.07)

# Show the Metric for filldrops
# This is a diagnostic to determine the threshold "lessthan" in the ConditionalFilter
# To run, remove the # in the line below and put a # to the left of filldrops() 7 lines above
# ScriptClip(last,"Subtitle(String(YDifferenceToNext() ))" )

mvtools2.dll is here:
http://avisynth.org.ru/mvtools/mvtools2.html

Please read the original article(s) on this blog, AND read the uber-original article on:
http://www.dvxuser.com/V6/showthread.php?237584-HDMI-Capture-Problem-SOLVED-AviSynth-RULES!

THE ABOVE IS A SCRIPT FOR “AVISYNTH” AND ONLY RUNS ON WINDOWS PCs!! READ THE FIRST PAGE OF THE LINK ABOVE

19
Apr
11

Panny GH2 + HDMI + Recorder = BINGO!

UPDATE: Jorgen Escher has made a Quickstart ready-to-run archive. If the instructions below are above your station, don’t feel ashamed to jump to this post by Jorgen.  

!! Warning: ADVANCED ABRACADABRA STUFF AHEAD !!

Much debate has been going on on the web about the feasibility (can it be done) and the quality (is it clean?) of recording from the Panasonic GH2 camera’s HDMI output.

With the release of the Atomos Ninja (a sub 1000$ 4:2:2 Prores field recorder), and of course by using PC capturing cards such as the Black Magic cards, the GH2 HDMI signal can be captured without a problem.
But before you’all start whooping and cheering, let me warn you that – in order to get editable footage – there is a special workflow required.

Let us first look at the workflow before, during and after recording – let’s say “on the set”:

  • Make sure the camera is switched off and connect the HDMI cable to both GH2 and recorder, switch on the GH2 and then switch on the recorder.
  • Select the Cinema 24 mode (24H)
  • I advise to use the Nostalgic picture style with all controls dialed down for flattest picture
  • Switch off the Highlight indication (this is outputted through the HDMI while recording!)
  • Make sure to insert a memorycard since we will be recording HDMI and AVCHD (camera) simultaneously
  • Start the GH2 recording FIRST
  • Now start the recorder
  • Stop the recorder first after the shot
  • Now stop the GH2
If you record the GH2’s externally as described above, your footage will be recorded without signal breaks, frame skips and/or other damage.
Because the LCD of the GH2 (and the HDMI output) use a degraded picture in live view mode, pressing record on the GH2 prior to recording from HDMI is an absolutely must.
If you use the Ninja, you’ll end up with a 4:2:2 Prores (HQ) recording, but – bummer – that’s not what actually arrived at the recorder’s input. The HDMI signal from the  has been described by Barry Green as “screwed up 4:2:0”, but other tests by Jorgen Escher shows that it’s really 4:2:2 that has been deliberately crippled by Panasonic to make the camera less interesting for professional vido use. This “cripple” mainly exists of timing disturbances, applied to both the video timing (“field cadence”) as well as the timing of the separate chroma channels.
Despite everything, HDMI recording eclipses the AVCHD recording in many ways, such as:
  • More detail in shadows (less muddy blacks)
  • No compression artifacts
  • Better overall detail
  • Better color rendition
  • Different noise pattern (finer)
  • Less pronounced solarization (a.k.a. color-banding -> yes, this is an 8 bit camera)
Watch out for this drawback: the GH2 does not output sound on it’s HDMI! So you’ll have to use the sound from the AVCHD recording, or feed sound into your recorder.
But, without any special further processing of our footage, the following artifacts will be immediately noticeable:
  • A double or missing frame “hick-up” approximately every second
  • Red shift (red bleed)
  • Gamma shift (washed out) on mac
  • Sound we have a .7 second delay, throwing mouths out of sync

At first glance, the HDMI recorded footage is absolutely useless and it will scare the hell out of you if directly loaded into an editor.

But here my personal heroes “Ralph B”, “PDR” and “GrgurMG” – senior members of the popular  DVXUser site -come to the rescue!
They have developed a marvelous script for a program called “AviSynth” that will process all your GH2 HDMI footage in 100% usable, editable 4:2:2 footage! All problems solved!
This makes the GH2 + Ninja combo a match made in heaven! Considering that we are talking about a sub-2000$ solution!

The pros of the workflow using the AviSynth solution are:

  • Fixes frame and field timing (cadence) inconstancies
  • Fixes color shifts
  • Fixes gamma issues
  • Fixes sound sync issue
  • Will do conversion to other codecs on the fly
  • If you’re using a Ninja, you want to backup or transfer your footage to another system anyway, so running it through AviSynth does not necessarily means an outrageous complication of your workflow.
  • Batch processing
  • A lot of AviSynth help, information, examples and fora to be found on the web

The cons of the AviSynth route are:

  • It’s a Windows based solution, so it should either run on a Windows PC or in a Virtual PC environment on your mac (e.g. VirtualBox = free). We now use a dedicated cheap Windows7 barebones system for the job.
  • You can not write the processed footage back to ProRes, because there is no PC/Windows ProRes codec that will write files – only read. The solution is to use either the build-in huffyuv lossless codec, Cineform (not free), AVCHD or the Avid DNxHD 4:2:2 codec (free). The latter has a MOV wrapper and can be imported directly in your Mac’s NLE.
  • You will have to download and install several programs and execute one or two by hand – if you’re a real PC novice, this will probably blow your brains out – as for the rest: you’re probably safe.

So, where do i get started?! Here: http://www.dvxuser.com/V6/showthread.php?237584-HDMI-Capture-Problem-SOLVED-AviSynth-RULES!

Remember the following important facts about AviSynth:

  • AviSynth is a non-visible running-in-the-background kind of tool, you install it and that’s it
  • You use a standard text editor such as Notepad to write or edit the script. You need to rename the file to have the .avs file extension.
  • The program that executes the script is a batch file that calls another program “called FFMpeg” that takes care of the creation of the output file
  • Do not be alarmed by all this, AviSynth, FFMpeg and the other tools are available with one-click installers and need no further attention when installed.
  • You will find a shopping list below with all download locations and installing instructions

As a Mac FCP user, i have altered the original script in the following way: removed the color correction because i don’t want any detail smoothing and added gamma correction. Here is the script we now use with the Ninja recorder footage:

LoadPlugin("C:\Program Files\AviSynth 2.6\plugins\QTSource.dll")  # change paths to your plugins location
LoadPlugin("C:\Program Files\AviSynth 2.6\plugins\TIVTC\TIVTC.dll")
LoadPlugin("C:\Program Files\AviSynth 2.6\plugins\FDecimate\FDecimate.dll")
QTInput("C:\Program Files\AviSynth 2.6\PROCESSING09.mov") # change to your input file location
AssumeTFF()
TFM(mchroma=false, pp=5)
FDecimate(threshold=0.5)
delayaudio(.07)
AssumeFPS(24000,1001)

# Chroma Fix - Optional, but highly recommended
FixBrokenChromaUpsampling()
ConvertToYUY2() 
# Mac users gamma correction
ColorYUV(gamma_y=-34, gamma_u=-34, gamma_v=-34)

# end of AviSynth script.
The batchfile i use for passing the AVS scripts (for each MOV file) to ffmpeg/avisynth looks like this:
for %%a in ("*.avs") do ffmpeg -i %%a -vcodec dnxhd -b 175M -an %%~na.mov
pause

Resulting in 175MBit DNxHD MOV files.

Still with me?

What you need to download and install on your Windows PC:

After installation of all the above, edit the script with Notepad or other text editor in such a way that all paths are pointing to the correct folders. You can also copy the necessary DLL files to one Plugins folder of your choice. File extension should be .avs
Finally, create a batch file (.bat) with Notepad or other text editor containing the batch file code above. File extension should be .bat
Run the .bat file. FFMpeg will start in a console window and reports any errors or progress. The resulting file will be named after the .avs script and will reside in the same folder as the avs script.
Phew…! That was heavy – but very worthwhile!
Many thanks to the magicians at DVXuser! Do not forget to check out the original script for non-mac users



twitter.com/martinbeek

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