All is possible

Author: carlomacchiavello Page 6 of 18

The difficulty in seeing beyond what we think we see

Those who work in a certain way have to deal today with a running world where the phone does everything from photography to video, post-produces it, applies filters and uploads it to youtube. This is all fine if you stay in the mobile realm and see from the same the finished footage, whereas if not, many complications may arise.

I am a proponent of the convenience of using any means possible to accomplish our purpose, but it is important to know the medium well, its limitations and how to handle them. Modern cell phone cameras (from 5-6 years ago) can capture video with very good quality, it is just a matter of not neutering their capabilities, the same thing happens with many cheap cameras.

Myth 1: but I am seeing it well here on the cell phone
Most tablets and cell phones rework images such as contrast and color to make them “prettier,” often saturating colors according to brands more red and blue, more orange and green, etc.
Some cell phones like my Z5 also apply some kind of realtime motion re-processing like some telvisors, so seeing a video on the cell phone means nothing about its quality

Myth 2: On the camera monitor you can see it well.
There is no camera that has a monitor that is adequate as a number of dots to the footage being captured, the footage is scaled and softened by the scaling, so you can’t really see the image for what it is at all, but only for what its translation is, plus most cameras you can change the color temperature, contrast, brightness of the monitor and so what we see is only distant relative to the original footage

Myth 3: It looks good on the monitor, it’s recorded well
except that if we are reviewing footage, most cameras show the through signal, not the recorded signal, so if there are recording or compression flaws we cannot see them until we review the material. There used to be professional cameras that allowed viewing with “deferred” so what you saw was actually the recorded, but today we see the through signal so the risk of not seeing defects or not realizing how poor the image is is very high. Also consider that even a cell phone has a more than decent sensor, but from there to what is recorded there is a gulf, for example my sony Z5 has a very good sensor, but it records very bad compressed jpgs, and in videos it applies (we don’t know why) a contrast mask on the fullHD footage that massacres monstrously the softness of the images and the real detail, you have to use external apps to record the real quality of that sensor otherwise you might get the impression that the images are low level.

Myth 4: why do you have to take up so much space with movies in xyz codec, h264 looks good, actually better h265 so it takes up less space.
very compressed formats like h264 and h265 have so many limitations, the more compressed they are the less detail they record, and the less you can process the movies. If you don’t have to do color correction, if you directly edit the footage without doing anything, maybe you can use a very compressed format, but as soon as you have to do a minimum of post, the inconsistency between frames of compressed formats shows its limitations, if I have to lower the brightness of a sky I will see blocks of colored cubes appear, because the codec expected to see those details, if we try to open the shadows a little we will see many elements moving in the shadows, not as grain, but as blocks changing shape, from green color to magenta, preventing such processing.
The compressed format also has nefarious effects on movement, if we are shooting very detailed images, such as trees with moving foliage, water, a meadow, a girl’s hair in the wind, if we exceed the limits of the capture buffer we can see compression artifacts in the moving elements.

Myth 5: Why do I have to use log, protune, these footage getting ugly and then make it right, better to capture it right now

Log capture is a way to capture better and preserve all the information in the footage, if you have to do postproduction of the footage the log will make the brighter highlights burn less, and there will be more detail in the shadows.

It’s not a matter of capturing badly to see well, it’s capturing as well as possible to extract as much information cleanly from the image that has its limitations. For this reason they are introducing logging even in less expensive cameras, and in some cell phones, for example iPhones from 7 onwards with the Filmic Pro app you can use the log profile to capture better information.

Usually those who complain about this type of capture have never had to deal with postproduction in a serious way and therefore have not seen what the limits of manipulating compressed footage and/or without a capture log curve are.

Myth 6: On my television set, this file looks better
proportional to the first myth, but more extensive, so much so that I devoted an entire article to it…. The amount of processing that a modern TV performs is so extensive that it requires much explanation as to why each TV is different and more or less destructive on images.

Why are Blackmagic cameras ever accused? 

Unfortunately, the web tends to be always provocative, accusatory, and it always seems that the world is full of flaws.

The funniest thing is that people who don’t own a product tend to blame the product itself. It happens with phones between Ios and Android, between photographic brands, and videos.

I wonder why many people often accuse the short lived batteries the Blackmagic Design Cameras, which are unusable cameras, that it’s impossible to work or shoot videos in that way …
just over 40 minutes and if we also attack an external drive just over 30 minutes … what stuff … really unusable …

To have a full HD display always active, a sensor that captures in raw 13 stops of dynamic range and maybe also feeds an external SSD and more …

the ingenious Vizzini would say inconceivable … Er …

All this in a world where all the other cameras shoot for hours with the same battery, right? Or, not? 

 

  • How long does the battery of an Osmo Mobile? 
    35 minutes (Dji Site Specifications)
  • How long does the battery of the Osmo Action? 
    Up to 34 minutes (Specifications Dji website) .
  • How long does a GoPro without using wifi? battery last? 
    up to 60 minutes (GoPro website specifications)
  • How long is the average battery of a photo camera that makes videos at the highest quality?
    65-80 minutes depending on the use of the camera, autofocus, stabilization etc ( On the official sites you will find only the number of shots and not the duration in video ... they are photo cameras)
  • How long does the gh5 battery last when recording in 4k intraframe? 
    64minutes (75 if you use the patona green, i had it)
  • How long does the Dji Osmo Pocket last?
    up to 140 minutes (According to specific site recording in Fhd), perhaps one of the few machines optimized for consumption, battery size, performance on camera and gimbal. 

It is curious that no one ever asks a question, such as how it is possible.
that the other cameras, not having to feed huge displays like that of the pocket4k / 6k, not having to record such large amounts of data, not having to power an external disk, last as long or less than the pocket itself …

 


Covid19 – 5 – phone to Webcam

The Covid19 forced the world to accelerate so many procedures, forced the technology reticents to adapt, to learn what by laziness they avoided, unfortunately this created a thousand problems not only for those who were not ready, but also for those who were ready not to be equipped at home to manage connections for school, work etc.

Not everyone has a good webcam, and it’s useful to have it for both smartworking and OnLine lessons, but good webcams (according to specifications) cost hundreds of euros and often the video quality is not as amazing as they are described, while nowadays we all have in our pocket a discreet or great room in our Smartphone.

Going to the Kinoni website you can download the driver to use your smartphone as Webcam, after installing the connected app on your iPhone or on your Android. Without spending a penny you can use the free app to do the tests and if you see that it is the optimal solution you can as less than 10 euros buy the paid app with more control, resolution up to fullHD, use phone audio, etc.

From the site you download the driver Desktop
https://www.kinoni.com/

To test, you can use the free app IOS

https://apps.apple.com/us/app/epoccam-webcam-for-mac-and-pc/id449133483

To use all the features there is the full IOS 8.99 app

https://apps.apple.com/us/app/epoccam-webcamera-for-computer/id435355256

To test, you can use the free app Android

https://play.google.com/store/apps/details?id=com.kinoni.webcam2&hl=fi

To use all the features there is the full android 5.99

https://play.google.com/store/apps/details?id-com.kinoni.webcampro&hl-fi

 

I pay for it, it’s definitely more reliable

This post comes from the fact that I do not know what to do while I am observing a semi-infinite list of files to convert, in an openSource program because the commercial programs that I pay almost 1000 euros per year subscription for the umpteenth time have resubmitted the bug of the VBR…

In short, when compressing video files with technologies derived from the logic of the gop, group of picture, you can define a tot of data per second, constants (so value / n frames per second) or variable value according to the content (Variable Bit Rate), now all recording systems use this second option because it optimizes quality, space occupied, device management in general.

for some years (from 2015 in particular) a well-known suite has a recurring bug that randomly disappears and reappears, so if we take a VBR file, we put it on a timeline, or we do convert it in a batch format the resulting file will have the audio that will go out sinc in a completely random way, because it seems that there is some problem to keep the synchronous audio video between frames and images. Even if you export only the audio and reimport the resulting wave, it will no longer be synchronous with the original files.

The embarrassing fact is that instead a whole series of free/opesource products do not have this problem. And the only solution suggested by the same company is to convert to a DI format or even the same compressed format and then edit it…

When I was paying for the perpetual license, the encoding and decoding codecs were licensed by the German MainConcept and these kinds of problems did not exist, today they update every 6 weeks the software, every three times there are notable bugs like this.

Solution 1 : Use software that uses its codecs to convert to a Di format that does not generate the defect

Solution 2: Leave the suite and move to more stable products

Solution 3: Sue that company for a series of work-related damage [ah dimenticavo, non lo può fare nessuno, perchè durante l’installazione se si leggessero le righe piccole si saprebbe che il software viene fornito as is, e l’azienda non è responsabile di malfunzionamenti, danni derivati da problemi del software etc etc]

If you can, follow route number 2, otherwise look for one of the many ffmpeg interfaces and solve with it the problem of conversion.

 


Covid19 – 4 – Battery Tips

The batteries we normally use with computer and filmaking are based on lithium-ion technology, a technology that has seen so many evolutions in recent years.

There are many myths and legends that are grounded only in the first versions of lithium-ion batteries, modern batteries have fewer problems than previous technologies, but of course they have time limits of life and a maximum of charges and recharges, so good use of batteries and good maintenance is a good habit to maximize the yield and especially the lifespan of batteries.

Without going into the technician, a battery is charged when it has a potential difference between positive and negative of a certain value.
The battery expresses its potential in Volt and amps, so when it needs to be charged it will apply some voltage and a certain amperage to restore this difference in potential.

During the charging phase the device / battery “asks” the charge and the charger “offers” the power charge up to its maximum charge value in Volt/ Ampere.

The life of a battery

The duration of the ability to retain and dispense the charge is determined by a number of factors:

  • number of charge cycles – download performed
  • temperature at which the battery was subjected
  • Fast charge vs slow charge
  • battery age (years since battery creation)
Number of charge cycles

Batteries have an almost finite number of charge and discharge cycles, which normally outpace battery life, so we don’t have to worry about how many times we’re going to charge a battery. A common number of cycles is around 1000 cycles up to 8000 charging cycles for some high-quality batteries. Assuming you use the battery every day, charging it every day you could charge it for about 3 years without affecting the battery.

The heat is his enemy

The heat generated by the charge/discharge or the heat outside the battery-powered device battery, affects the quality of the chemical elements contained inside the battery and their ability to work.

Many people treat batteries badly, abandon them in the cold, in the heat, and all these operations have a clear impact on both the performance and the duration of the battery charge.

Fast Charge vs Slow Charge

When we load a 12v battery we can use a 12v 1 amp power supply or 6v 2 amps, the difference between the two cases is that with a larger amperage we can accelerate the charge, but this generates more heat, which is not good for the battery and could give damage to the wiring. So using fast charging could wear out the battery’s ability to retain power. I use the conditional because this wear is determined more by heat generation than by chemical damage, so it depends on the situation, the charging system and the management of the charge. Many chargers contain charge control chips that monitor the situation and handle the outgoing amperage.

Battery age

The only real flaw in lithium batteries is that they have a limited lifespan, so it’s important to know the date of battery production because as time goes by the capacity will go down physiologically, so even when we buy batteries for the devices it is important to check the date of production.

Conservation

So summed up to properly store a battery the best strategy is:

  • Make a refresh of the charge every 4-6 months.
  • Store in a cool, dry place.
  • Don’t let the battery drain at 0%.
  • Up to 40% charge can be left.

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