11 votes
Accepted

Digital cameras see black scrolling lines when filming light from my desk lamp

Cheap (to make) LED lights will flicker at twice the mains frequency. There are many ways of overcoming this in the design of lights, such as using a larger smoothing capacitor (which makes the light ...
Pete Kirkham's user avatar
9 votes

Digital cameras see black scrolling lines when filming light from my desk lamp

The reason is very simple. LED's are not constantly turned on, but flicker at a very high rate, usually due to fluctuations in your powerline. Your video camera records at a fixed framerate and as ...
LPChip's user avatar
  • 191
7 votes
Accepted

SDI - serial digital interface

General SDI vs. HDMI Information SDI is easier to connect to other professional equipment than HDMI. It is an all purpose signal, as opposed to HDMI that was originally intended only to connect to ...
Michael Liebman's user avatar
5 votes

What are Grey Balls used for?

Yes, they are used for adding visual effects in post. The mirrored ball is for creating an environment map or reflection map. These maps provide the same lighting from the real scene to the virtual ...
user1118321's user avatar
  • 2,156
4 votes

Why do cinema cameras cost too much?

Look at it from a data rate point of view: a GH4 records 4K at 100 Mbps. A RED Carbon Fiber WEAPON records at 300MBps. That's 24x the data rate. Look at how very much more expensive it is to ...
Michael Tiemann's user avatar
4 votes
Accepted

Why use different camera angles?

Different angles are used for many reasons. Wide and/or long shots are used to establish the setting where the video is being shot. Medium shots are used to show the relationship between people and/...
Richard Crowley's user avatar
4 votes

What is causing these horizontal lines moving vertically up the whiter portions of the video?

You seem to have a flickering light source that is out of sync with the camera's rolling shutter. Traditional lights You should first verify that you are filming in 60/30/24 fps in regions whose power ...
Duvrai's user avatar
  • 803
4 votes

Digital cameras see black scrolling lines when filming light from my desk lamp

LEDs are a very fast reacting light source, far faster reacting than incandescents or even flouresecents. So if the current through the LED varies rapidly the light output will vary equally rapidly. ...
Peter Green's user avatar
4 votes
Accepted

Camera flash produces unwanted artifacts on the video

This is actually a collateral effect of the concept of rolling shutter. Most video devices do not expose all the frame area at once. They expose starting from one side and (up or down) and move from ...
Rafael's user avatar
  • 1,182
4 votes

What is the minimum camera requirements to create professional quality videos?

The camera only plays a part in what makes a good, clean image. The most important parts are Lighting, Lenses and Knowledge of the person operating the camera. If you film in a dark location and have ...
Florian Claaßen's user avatar
3 votes
Accepted

How to get the Cinematic look

There are a few important things to consider: Lighting is perhaps the most important aspect to creating a filmic image. A lot of filmmakers like to use natural light such as Innaritu on The Revenant. ...
Alex's user avatar
  • 809
3 votes

Why do cinema cameras cost too much?

The image processing of cinema cameras is done with fairly inexpensive FPGA chips, that doesn't explain a 50.000€ price difference between I.e. a gh4 and a arri Alexa. The FPGA chip used in blackmagic ...
Hans Meiser's user avatar
3 votes

Why do cinema cameras cost too much?

You are probably comparing cameras that record compressed 4k video with cameras that record uncompressed video, i.e. RAW footage. The ARRI ALEXA and RED Epic belong in the latter category. The ...
MoritzLost's user avatar
  • 5,412
3 votes
Accepted

What are Grey Balls used for?

The grey balls are actually used like the grey cards but with added lighting data cause they are spherical and refer to the surrounding light sources better, they usually reflect 18% of the light and ...
Reuben Tilahun's user avatar
3 votes
Accepted

How to record HDMI video with USB?

You already stated your options and you only have one that would work: you need a frame grabber. A frame grabber is a specialized chipset that does a very specific task. Sometimes such devices are ...
user3643's user avatar
  • 2,244
3 votes
Accepted

How do I replace my organisation's event video camera?

Firstly, that camera has a 29 minute 59 second recording limit. If your speaker goes for longer than this it may not be suitable. Apparently this is due to some countries charging higher import duties ...
stib's user avatar
  • 13.7k
3 votes

How does shutter speed affect the video?

A high shutter speed can make individual frames look more crisp but make large motion look like it is stuttering. e.g. fast panning looks like it is flickering or jumping A low shutter speed can make ...
GiddyUpHorsey's user avatar
3 votes
Accepted

How does an optical viewfinder on a film camera work?

There are three ways that film cameras do this: Using a rangefinder, i.e. a viewfinder that doesn't actually view through the lens. Common on cheaper consumer format cameras such as super-8 Using a ...
stib's user avatar
  • 13.7k
3 votes
Accepted

How to realistically add planet in the sky using 3d camera tracker and avoid overlapping with objects in the foreground?

If the blades are rotating, and the camera is moving, you need to create a good foreground layer with anything the planet is supposed to be obscured by. So from the image it looks like it will be ...
tomh's user avatar
  • 7,757
3 votes

Best hidden camera rig techniques

I've been on guerrilla shoots where they had a GoPro peeking through an O on a protest sign, held at head height like the protester isn't actually protesting right this minute. Also, I've seen a ...
Tetsujin's user avatar
  • 616
2 votes

What is good software for camera recording under Linux?

OBS (Open Broadcaster Software) is multi-platform (OBS is widely used in video game streaming). I haven't tried it yet myself for multiple cameras, but I know it supports at least one (as many ...
Xavier's user avatar
  • 21
2 votes

Reference Request: Camera Movements

Mic shot looks like a dolly back tilt to track the subject. This is a compound movement that is natural to do with a hand held camera but more challenging when using a digital camera. Try tracking ...
3pointedit's user avatar
2 votes

What is the cheapest camera I can plug external microphone to?

If anyone is still looking for a similar setup that won't break the bank, I'd go with a laptop mounted cam - I have a Logitech HD Pro Webcam C920 which can be mounted on a tripod, too. The quality is ...
Silvia's user avatar
  • 21
2 votes

BMPCC + rafcamera arri b to mft + optar 1.2/12mm = vignetting

I'm not familiar with the setup you described, but does that adapter have some sort of iris control built into it? I have the adapter pictured below and it doesn't allow the BMPCC to adjust the ...
Manly's user avatar
  • 290
2 votes
Accepted

how can we shoot tv show so "tarak mehta ka ulta chasma" it will look like "house of card"?

I see four basic differences (in what I believe is the correct priority order): Lighting. The lighting on Kevin Spacey is classic three-point lighting with warm fronts, a 2:1 key/fill ratio, and ...
Michael Tiemann's user avatar
2 votes

Are movies recorded on film?

Yes, many big budget features are "still" shot all or partially on film. Here's a list of a number of movies shot on film for 2014: Reasons vary, but many consider film to have a particular reality ...
integris's user avatar
  • 390
2 votes
Accepted

Camcorder vs. not a camcorder and separate audio and video recording

Terminology In theory, a camcorder is a video camera that also records video. A long time ago, this was an important distinction, since movie cameras (which are analog and record to film) and other ...
MoritzLost's user avatar
  • 5,412
2 votes

Why do cinema cameras cost too much?

In addition to the points above, keep in mind that cinema cameras also have a host of features not found in cell phones and lower-end cameras, such as removable lenses, better autofocus, better bodies ...
user1118321's user avatar
  • 2,156
2 votes

which are the good camcorder or DSLR to make video tutorials or MOOC to show on wide screen using projector?

The SONY HXR NX1 is a staple of capturing professional-grade content that can be produced on its own or incorporated into other productions. Yes, there are higher-end cameras, but this is a solid ...
Michael Tiemann's user avatar

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