2 years ago
How to make a video call?
Making a video call using Skype for Android is very easy. To do this, follow these steps:1. Sign in to Skype.
2. Select the Contacts tab.
3. In the contact list, find and select the person you want to call via video.
4. To start a video call, select Video Call.
How to switch between front and rear cameras?
Select from the following video options:
Front Camera: Switch to the phone's front camera.
Rear Camera: Switch to the phone's rear camera.
Turn off video: Stop broadcasting video (but you will still see the video image of your interlocutor).
If the video camera icon is not displayed, tap the screen to bring up the call bar.
On devices under Android control 2.2 (Froyo) you can only make video calls from the rear camera.
How do I activate Skype video calling on my Android phone?
To make video calls to people in your Skype contacts list, you may need to manually enable Skype video calling(depending on your Android phone model). To do this, follow these steps:
Sign in to Skype.
Select Settings.
Select the Activate video calling checkbox.
If you don't see video calling settings, it means your Android phone unfortunately doesn't meet the minimum technical requirements for video communication via Skype.
If on your Android phone If one of the following applications is installed, you will not be able to use video calling:
Skype mobile™ for Verizon
Skype to Telkomsel
Skype on 3 phones
How to change video calling settings?
Video calling settings allow you to change privacy and call quality settings.
To change video settings:
Sign in to Skype.
Select Settings.
Scroll down the window to the Activate video calling section.
You can set the following parameters:
Receive calls...: Select which categories of users you want to receive video calls from. If you do not want to receive video calls from strangers, select the appropriate setting.
Technical Details: Select this option to view the technical details of the call.
Video Quality: Select the video quality. The higher the quality, the more data will be transferred during a video call.
Answer calls automatically: Select this option to enable automatic answering of video calls.
How to ensure the best video quality?
The quality of video communication depends on technical specifications the network being used. The faster the data connection you use, the better the video quality will be. We also do not recommend running simultaneously a large number of other applications, as they will use your phone's resources.
Can I organize or participate in a group video call (video conference)?
Unfortunately, Skype for Android does not support group video calling. You can take part in group call, but only in voice mode: you will not be able to broadcast or receive video.
Shooting video with DSLRs ( DSLR ) - cameras became available relatively recently. This function first appeared in the Nikon D90 camera, released in August 2008, and appeared about a month later Canon EOS 5 D Mark II , who already knew how to shoot FullHD -video (1920x1080). By the way, despite the fact that Canon 5D Mark II was practically a pioneer; it was this model that became the most popular SLR camera used in professional video shooting.
The list of various videos, clips, films where a DSLR was used for shooting is very wide. Those who watched the well-known TV series “House M.D.” at one time probably heard that the last episode of the sixth season was filmed on CanonEOS 5 DMarkII . There is information that SLR cameras were also used in some episodes of other series, for example in the series “24 Hours”. Some scenes are successfully filmed on DSLR -cameras and in films. You can note the films “Captain America: The First Avenger”, “Iron Man 2”, “Black Swan”, “Finding Sonny” (the film was entirely shot on a Canon EOS 5D Mark I I ). And these are just some examples professional use. On the Internet, on popular video hosting sites youtube, Vimeo you can find just a lot of very attractive videos shot by enthusiasts and professionals. There are entire sections with training videos on the features of shooting with SLR cameras ( http://vimeo.com/videoschool/archive/dslr ).
Just great amount videos shot with cameras, constantly participates in various festivals and competitions.What is the secret of such success, because it was originally planned that video shooting would become only a kind of additional function SLR camera and certainly not a professional’s tool?
Decent arsenal
In our reviews of photo and video cameras, I have repeatedly drawn your attention to the importance of such a parameter as the physical size of the matrix (not the resolution in megapixels, but the size). The larger it is, the more equal parameters, the image quality will be higher. So, the size of the matrices in SLR cameras is completely in order. (In Fig. 1 you can see the difference in matrix sizes SLR cameras different classes and the matrix of a top-end household video camera - as you can see, the difference is very big.) But it is necessary to make some very important remark.
The fact is that in SLR cameras, not the entire matrix is used when shooting video. Moreover, manufacturers do not disclose information about which part is used (groups of pixels, lines), how video pixels are formed, etc. However, even such partial use of the most powerful matrices of SLR cameras is enough to provide good detail. FullHD -video and high sensitivity when shooting in low light.
I also definitely want to note that the size of the matrix affects the depth of field of the imaged space (DOF). With a large matrix, the depth of field can be made very small, for example, in a facial portrait, leaving the eyes sharp and the ears blurred, thereby achieving volume in the image. Good effect can also be obtained by blurring the background and foreground, leaving only the main subject of the frame in sharpness.
Let’s also not forget that for SLR cameras there is simply a huge fleet of all kinds of lenses: from wide lenses to telephoto lenses, from simple budget models with basic focal lengths to high-quality fast prime lenses (see photo). In general, DSLR cameras simply provide the greatest opportunities for creativity. The main thing is to be able to use all this to achieve the desired result. It is not surprising that even professionals liked them so much. By the way, professionals also note the low cost of such equipment. A set costing under ten thousand dollars consisting of a full-frame ( FullFrame ) a high-end SLR camera, several necessary lenses and additional equipment considered a very affordable alternative. For example, some specialized digital cinema cameras can cost tens of thousands of dollars ( ARRIAlexa - $60,000, SonyF65 - $65,000, RedOne - $25 000), and the cost of a camera kit with additional equipment can reach hundreds of thousands of dollars. In addition, many note that SLR cameras, even with a lot of additional equipment (microphone, mount, remote screen, etc.) turn out to be very compact, which can be very useful when shooting certain scenes.
By standards household use, sums of several thousand dollars, of course, will seem prohibitive. But also with more affordable “cropped” cameras (matrix size APS—C ) with the right approach, you can also achieve good results.
Not so simple
Why didn’t the video shooting mode appear in DSLR cameras right away? The thing is that this mode in such cameras is to a certain extent alien. For many, the basics of the design and operation of a DSLR camera have long been known, but for beginners, I would remind you that DSLR cameras contain a mirror, hence the name. This mirror is located in front of the matrix and in normal mode covers it with itself and re-reflects the incoming rays to the viewfinder, with the help of which sighting is carried out. During photography, the mirror rises and rays of light fall on the matrix. The fact is that in normal mode (when the mirror is lowered), the rays are reflected not only into the viewfinder, but also onto special phase focusing sensors, which provides fast “mirror” autofocus. IN regular cameras There are no such sensors, and focusing is carried out by the light-receiving matrix itself. During video shooting, the mirror remains raised and the phase sensors do not work, and focusing has to be done by the matrix. The whole difficulty is that DSLR — cameras and their lenses are designed to work specifically with special phase autofocus sensors, and an attempt to rebuild this entire system for matrix focusing is quite complicated.
As a result, autofocus has appeared in video mode, but the quality of its work in many cameras is far from ideal. Moreover, sometimes it turns out to be so slow that it becomes very inconvenient to use. In new models, manufacturers are trying to improve this parameter, but you can’t count on fast, simple autofocus, as in conventional household video cameras. If you want to achieve good result, you will most likely have to use manual focusing. Don’t forget about the relatively small depth of field when shooting with DSLRs, so you’ll have to rotate the focusing ring a lot. (*note at the end of the article)
But, as often happens, many rules have exceptions. In its latest DSLRs, the company Sony I used a very interesting technology. In these cameras the mirror is translucent and does not rise at all. Due to this, it was possible to implement very fast autofocus when shooting video. By the way, we have just one such model in our test, so we will dwell on this topic in more detail in the description of the camera itself.
Summarizing everything said in this block, it can be noted that shooting video with SLR cameras is a rather complex activity that is not suitable for all users. For simple everyday tasks, a regular household video camera will be preferable. They are also not very suitable for reportage shooting. But if you approach the matter intelligently, with preliminary preparation, the result can be excellent. For enthusiasts DSLR -video can really provide a large field for activity and experimentation.
In order to evaluate in practice the features of shooting video with SLR cameras, we have selected several models of different classes that are common on our market. The most popular model acted as a high-end full-format camera Canon 5D Mark II , to evaluate the video capabilities of DSLR cameras primary class we have chosen the model Nikon D 5100. The picture was perfectly complemented by an extremely interesting model with not quite standard capabilities. Sony SLT—A 65. In general, the field for assessing the features of shooting with SLR cameras turned out to be very good. Read more about the video mode of each model below.
In the picture you can see big difference between the sizes of matrices used in SLR cameras (relatively speaking, the yellow rectangle is high-end cameras, the red rectangle is mid-range and entry levels), and top-end consumer video cameras
The arsenal of lenses for SLR cameras is very large, which expands the field of possibilities and experiments when shooting
The design of a typical digital SLR camera (example Canon EOS 5 D Mark II)
Branded sores
Moire can appear when shooting objects with a “regular” structure, for example, on fabrics with a pronounced texture, brick walls, grids, etc. Screenshot taken from a video shot on a DSLR camera
DSLR cameras are indeed capable of producing generally very high-quality video, but in DSLR -The video also contains some not entirely pleasant moments.
The most typical unwanted effects that appear on video recordings from DSLRs are moire and rollingshutter. Rollingshutter http:// ru. wikipedia. org/ wiki/% D0% A0% D0% BE% D0% BB% D0% BB% D0% B8% D0% BD% D0% B3_% D1%88% D0% B0% D1%82% D1%82% D0% B5% D1%80 ), both of which are due to the nature of DSLR camera matrices and their use for video. The figure shows an example of the manifestation of moire (the screenshot was taken from a video shot on a DSLR camera). Moire appears not only in videos from SLR cameras; this effect also occurs in recordings from conventional video cameras and in photographs. Just on DSLR -video it may appear more often.
Rollingshatter is a defect associated with the peculiarities of reading data from the light receiving matrix. In KPOP ( CMOS) matrices, which are used in almost all modern SLR cameras, information is not read from the entire matrix at once, but line by line, line by line in sequential order. When you quickly move the camera horizontally, a situation arises where objects become slightly distorted, for example, vertical pillars become slightly tilted. This happens due to the fact that during the time of reading information from the matrix, the position of the object in the frame has time to change.
Rollingshatter affects not only DSLR cameras, but also any other cameras with CMOS matrices. There are some video processing techniques to eliminate this effect, but some solve the problem by limiting the use of scenes where this effect can clearly manifest itself.
Interlacedvs Progressive?
Among high-definition video formats, many cameras still have 1080 shooting mode. i with interlaced scanning (much more common in camcorders rather than SLRs). Letter i(I nterlaced) in format names indicates interlaced scanning, and p (Progressive) - to progressive. My advice for choosing a video format is quite simple: try to use progressive scan video modes exclusively. The fact is that modern devices display, whether LCD or plasma TV, computer monitor (even CRT), projector displays a progressive image. When playing video with interlaced scanning on such devices, conversion will occur, which, by the way, does not occur without loss of quality. In addition, such videos are less suitable for editing. I recommend choosing a shooting format with progressive scanning, even if it is not so fast, for example, 1080 modes are available i50, 1080p 25 or lower resolution (720 p 50). By the way, it’s not a fact that the video is in 1080 format i 50 will be more detailed than 720 p50, because FullHD mode 1080 i 50 is “inflated”, since each frame does not have the full resolution of 1920x1080 pixels, but twice as low vertically - 1920x540 pixels.
What shooting speed should I choose?
Some cameras allow you to switch the TV standard, which allows you to expand the choice of recording speeds when shooting video
In videos Cin25FPS.MTS and Cin50FPS.MTS located on the disk, you can see the difference in the smoothness of the video when shooting at 25 and 50 fps.
Typically, DSLRs as well as camcorders provide a choice of video recording speed. Cameras intended for sale in Europe can shoot at 25 or 50 fps (format PAL ). And cameras intended, say, for the US market, and these can be absolutely identical to European models, shoot at a speed of 30 or 60 fps (format NTSC ). This is due to the standards used in the countries for which the camera is intended.
It is curious that some SLR cameras, including the models present in our test Canon 5 D Mark II and Nikon D 5100, allow you to select formats PAL/NTSC manually. When changing PAL to NTSC the speed is set to 30 fps instead of 25 and 60 instead of 50 (if the camera supports this speed, Canon 5 D Mark II and Nikon D 5100 - not supported).
In principle, in most cases this mode will be preferable, since it allows for slightly smoother playback, but our use of this mode (speed 30 or 60 fps) has one feature associated, oddly enough, with the frequency in the networks alternating current, which is 50 Hz. Fluorescent and incandescent lamps flicker, although this is almost invisible to the human eye. So, if you shoot at 30/60 fps in bright artificial lighting and 50 Hz supply networks, flickering may appear in the video. For clarity, we specially shot short videos where this effect becomes clearly visible (files on hi—TechDVD , LampFL25FPS.MOV and LampFL30FPS.MOV - shooting under fluorescent lighting at 25 and 30 fps. LampNakal25fps.MOV x and LampNakal30fps.MOV - shooting under incandescent lighting at a frequency of 25 and 30 fps).
When choosing between recording speeds of 25 and 50 fps (30 and 60 fps), in our opinion, it is necessary to give preference to the higher speed. During playback the difference becomes clearly visible. We placed two videos on the disk (Cin25FPS.MTS and Cin50FPS.MTS, by the way, in the recordings you can hear the sound of autofocus operation, read more about this in the camera review Sony SLT—A 65 on the following pages) taken with the same camera in the same conditions, but they put different speed. Try to reproduce them and judge the difference yourself. In addition, if you edit a video with an output frequency of 25 fps from videos shot at a speed of 50 fps, for example, if you want to post a video on a video hosting like YouTube, Vimeo , Where maximum speed playback is 30 fps, then you will have a certain frame reserve, which will be useful if you apply the effect SlowMotion.
A fairly common situation is when the camera shoots video in 720 format. p , that is, with a resolution of 1280x720 and progressive scanning, with a frequency of 50 (60) fps, and in 1080 format p (FullHD 1920x resolution 1080, progressive scanning) with half the frequency of 25 (30) fps. Which mode to prefer: more a high resolution or a higher shooting frequency? Here the question is individual, but, in my opinion, in in this case advantage for 720 format p50 (720 p 50). The loss of resolution cannot be called catastrophic, but you will have a smoother video or a margin of frames for the effect SlowMotion.
Such issues are completely resolved by cameras that allow you to shoot in 1080 format. p50(1080p 60), on this moment There are few such cameras, but their number is constantly growing.
Video shooting at 24 fps is also widely used in cameras. It is used to give videos a “cinematic” effect, because movies are shot with such frequency. Try it, maybe you will like this mode too.
Additional equipment
rig.jpg (photo in insert) There is a lot of additional equipment for filming and DSLR -video, moreover, it could be ka To simple, including homemade, devices, as well as complex devices for professional use
If they take the matter seriously, users sooner or later begin to think about additional accessories for the camera. The built-in microphones in DSLR cameras are often not of sufficient quality. In addition, the built-in microphones also record a lot of completely unnecessary sounds. For example, sounds of autofocus drives, clicks of switches, sounds of operation optical system stabilization. An external microphone will help you out of all these troubles. Moreover, it can be not just an external microphone attached to the camera itself, but also remote lavalier microphones.
A significant problem when shooting video is camera shake. This is even worse in DSLR cameras. And the fact that in addition to simply holding the device, you often also have to rotate the zoom and focus rings. In addition, the form factor of SLR cameras is sharpened, rather, for convenient viewing using an eye viewfinder, but when shooting video you have to use exclusively the screen and, accordingly, holding the camera becomes not so convenient. The most common solutions are various tripods. However, they significantly limit freedom of movement. Among enthusiasts DSLR -video widespread received a variety of DSLR rigs (DSLR— rig, Camera Shoulder Rig). The photo shows one example of such a rig. They come in a wide variety, from simple models costing several tens of dollars to ebay , to advanced devices for professionals costing up to $1000 and above. Some craftsmen make such devices from scrap materials. A funny example is a video where enthusiasts make DSLR rig made of wood! http://vimeo.com/11435910http://athan.se/diy-shoulder-rig/
There are also many accessories that allow you to use the viewing screen more conveniently..
If you need to switch from one camera to another during your intended animation, this can be done through compositing. For example, let’s assume that we are faced with the task of inspecting a landscape scene, that is, first we need to cover it close-up, and then view it in more detail. This automatically means that it is better to carry out a close-up inspection through a camera with wide angle lens(10-15 mm), which will allow you to assess the scale of the scene. At the same time, such a camera should not be used for detailed inspection, since its use leads to strong distortions (fish-eye effect), especially obvious at the edges of the scene. Therefore, for a detailed inspection, it is wiser to switch to a camera with a normal lens. Open or create a custom landscape scene and create two cameras for it: the first for a long view with a focal length of 15 mm, the second for a near view with a focal length of 50 mm (Fig. 66 and 67).
Open the window VideoPost and add three events to it: the first two are of type SceneEvent and represent views of the scene from the first and second cameras, respectively, latest event belongs to the type ImageOutputEvent and is required to obtain the final animation (Fig. 68). Increase the number of animation frames to 400. Set the event duration Camera 01 - from 0th to 210th frames, and events Camera 02 - from the 190th to the 400th frames. Please note that we have provided a certain interval of frames in which both cameras seem to be operating - this will allow for smooth switching from one camera to another. For an event ImageOutputEvent specify the duration from frames 0 to 400.
Rice. 68. Window VideoPost with three base events
In the perspective window, set the view from the first camera and, in the automatic key generation mode, create a set of key frames, simulating a gradual approach of the camera to the scene being viewed. These settings are made in the interval from the 0th to the 200th frames - that is, when the inspection from the first camera should be carried out (Fig. 69). Exit the automatic key generation mode and set the perspective window to the view from the second camera. Then create keyframes for it in the same way, which would provide a more detailed view of the scene. This operation is carried out in relation to 200-400 frames (Fig. 70). After this, for a correct transition from one camera to another, the corresponding events should be mixed. Select lines Camera 01 and Camera 02 and set their mixing method CrossFadeTransition(Fig. 71) with a duration from the 190th to the 210th frames. Click the button ExecuteSequence, set the visualization frame interval from 0 to 400, and you will get a full-fledged inspection of the scene, in which the viewer will first be presented with an overall picture of an impressive landscape in size, and then individual elements of the landscape will be shown more closely. Some frames of such an inspection are presented in Fig. 72.
Rice. 71. Mixing events by method Cross Fade Transition
Video with splash screen
In the last lesson, we created an animation of a laser beam moving along the contours of a letter (Fig. 73). Let's use the module VideoPost in order to use this animation to create a demo video with a splash screen playing before the start of the laser beam animation. According to the plan, the screensaver will begin with the display of a black screen, on which at first some inscription will appear in a kind of halo along the letter, then this inscription will gradually fade out, after which the animation itself will begin.
First, let's prepare auxiliary images. Open Photoshop and create a new file the same size as you specified earlier in VideoPost when creating a moving laser beam. Fill it with black and save it under the name BackBackground.png(Fig. 74). Add a caption to the center of this image and save it under the name BackgroundText.png(Fig. 75).
Switch to 3D Studio MAX, create a new scene and open a window VideoPost. Add three events to the queue ImageInputEvent and specify files as images for them BackgroundText.png, BackBackground.png And BackgroundText.png- for the top two events, set the duration from the 0th to the 30th frames, and for the bottom one - from the 29th to the 150th (Fig. 76). Link the top two events by assigning an event to them ImageLayerEvent with compositing method SimpleWipe(Fig. 77) - this will ensure that the black background is replaced by a background with an inscription that will appear letter by letter from left to right. Set for event SimpleWipe duration from frames 0 to 30. Highlight the bottom line BackgroundText.png FilterImages(button AddImageFilterEvent), indicate the effect Fade, click on the button Setup and make sure the effect is set to option Out(Fig. 78). For more convenient control of the results, even at this stage it is better to output the result to an AVI file, so add the image output event to the queue (button AddImageOutputEvent), click on the button Files, specify the file name with AVI extension ( Laser_new.avi) and its compression format (Fig. 79). Click the button ExecuteSequence, enable option Range and specify the start and end frames of the animation (in this case, frames 0 to 150). After generating the AVI file, view the result - at this stage you will see a letter-by-letter inscription appear on the black screen, which then gradually fades out (Fig. 80).
Rice. 76. The appearance of three events ImageInputEvent
Rice. 77. Linking events by method SimpleWipe
Rice. 78. Adding an event Fade
Rice. 79. Adding an event Image Output Event
Now we need to form a luminous halo around the inscription - for this purpose we will use the effect LensEffectsHighlight. It can only be applied to scene objects or materials, so create an auxiliary spiral object on the scene and make it renderable (checkbox Enable inRenderer in a scroll Rendring panels Modify) - rice. 81. Reduce the thickness of the spline (option Thickness) up to 0.05. Open the spiral properties window (command ObjectProperties) and install in the group G-Buffer for parameter ObjectID value 1. Add event to queue Scene(button AddSceneEvent), specifying a perspective window for visualization, set the duration of this event from frames 0 to 150. Move this event above the line Laser _new.avi. Highlight an event SceneEvent and add the event to the queue Image filter with effect LensEffectsHighlight(Fig. 82), click on the button Setup and make sure the effect is assigned to the object with ObjectID equal to 1. Immediately adjust the glare parameters - on the tab Geometry activate the parameter AltRays(responsible for alternating the length of the rays), and on the tab Preferences set for parameters Size And Points values are 25 and 7 respectively, and both parameters are from the group Distance Fade increase to 10 (Fig. 83). Run the event queue for execution and make sure that the result is far from the desired one, since now only highlights are visible on all frames (Fig. 84). To correct the situation, we first connect using the event ImageLayerEvent(method AlphaCompositor) lines SimpleWipe And Fade(Fig. 85), and then the line that appears after that AlphaCompositor- with string LensEffectsHighlight(Fig. 86). After this, the inscription will appear and disappear against the background of a halo of glare (Fig. 87).
Rice. 82. Window VideoPost after adding the event SceneEvent and assigning an effect to it LensEffectsHighlight
Rice. 83. Setting effect parameters LensEffectsHighlight
Rice. 84. View of one of the frames of the video after adding an event SceneEvent with effect LensEffectsHighlight
Rice. 85. First mixing method AlphaCompositor
Rice. 86. Second mixing method AlphaCompositor(event selection is on the left, window view after mixing is on the right)
Rice. 87. View of two frames of the video after setting up the blending method AlphaCompositor
Now all that remains is to connect the animation of the laser beam. Add an event to the queue ImageInputEvent and instead of the image, specify an AVI file with the corresponding animation ( Laseravi) - rice. 88. Set its duration from the 15th to the 451st frame. Highlight the top row AlphaCompositor and the line Laser.avi and set up their mixing according to the method CrossFadeTransition(Fig. 89) with a duration from the 150th to the 200th frame. This will ensure that at the beginning of the animation the display is weak, but gradually its brightness begins to increase and from the 200th frame it becomes maximum. Increase the duration of the event ImageOutputEvent up to the 451st frame inclusive. Click the button ExecuteSequence
