The Typical indoor Lighting setup

Posted by gajini on 12:30 AM comments (0)

The wrong lighting can cause your primary subject to be underexposed or overexposed. Light is the most important thing in digital photography and video recording. A good lighting can get a pro looking image or video out of a low budget camera and in bad lighting, video or image shot by a pro with an expensive camera also looks as if taken by a newbie.

If you're setting up lighting for indoor shots, there are four different light sources you need to keep in mind :

1. The Fill Light
True to its name, a fill light fills the scene with ambient light, and doesn't cast any shadows. In the daytime, the sun is your fill light-sunlight bounces around your house lighting up everything, so you don't have to bother about lighting ever nook and cranny. In the evening or at night, you can use a fluorescent lamp as the fill light.

2. The Key light
This is the light that will lay emphasis to the details on the main subjects of the scene. The key light is the brightest light in the scene, and it's what you'll be using to play with shadows and high lights, and you should invest a lot of time in setting this up.

3. The Background Light
This light is placed behind the subject to soften any unwanted shadows.

4. The Rim light or Kicker
This one is optional. The rim light is also placed behind the subject, and it adds definition to the subjects' edges. In the case of humans, it shines through hair (or on bald heads) for a halo-like effect.

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Introduction to Aperture

Posted by gajini on 12:27 AM comments (0)

As like other settings in digital cameras, most of the people always put aperture settings in Auto mode. Like other settings, with some experiments, you will be able to adjust aperture according to the conditions and what type of shots that you want to take. Unlike white balance and shutter speed, aperture make a lot of difference in images.

Aperture - definition
The diaphragm on the lens is the mechanism which enables the hole through which the light passes to change size. The hole is called the aperture. When the diaphragm is completely opened, the aperture is large, and it lets a huge amount of light thorough. When the diaphragm is closed to the size of a pinhole, the aperture is tiny, and it lets only a little bit of light through. With this in mind, you want to close the aperture on a bright and sunny day so as to not let too much light come through to the film or photo sensor. On a dark or dreary day you want to open the aperture so as to let as much light through as possible in order to get a good photograph.
Aperture settings, called f-stops, are determined by the manufacturer according to the focal length of the lens.

While the shutter speed controls the speed at which light is admitted, the aperture controls the amount of light that will reach the CCD. This can be imagined as black window that opens and closes continuously very fast (shutter) and a curtain (aperture) behind the window that controls the strength of the sunlight entering the room (CCD). The wider the aperture, the more amount of light that reaches the CCD.

If you are taking close-up then you should try increasing aperture as it will increase the Depth of field. Depth of field is the portion of image that is in focus. If aperture is large then, your subject will be in focus with background little blurred (because it is out of focus) which is very good for taking portraits or close-up shots which concentrates only on a single subject and not on the background.

In the above image, the spider is only in focus and not the background. The depth of field is high in this image that means aperture is very large.
If you increase aperture, depth of field will increase and if you decreases aperture, depth of field will decrease.
Taking the shots by increasing the aperture can also be helpful in low light conditions.

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Introduction to Shutter speed

Posted by gajini on 12:26 AM comments (0)

Shutter speed - definition
The time for which shutter remains open is known as shutter speed. For example, if shutter speed is 4 sec, then shutter will be open for 4 sec or you can say that the image will be captured after 4 sec (when shutter closes). Thats why while using low shutter speed, people are advised to use a tripod because till shutter remains open camera should be as still as possible. The range of shutter speed will vary according to model and make of camera.

In a camera, the shutter opens and closes to control the amount of light reaching the film. The longer it is open, the more light reaches the film. In a dark dreary place, you need the shutter to stay open longer to allow more light to reach the film. On a bright and sunny day, you need the shutter to stay open for a shorter time so as not to allow too much light to enter into the camera. Manually adjusting shutter speed can really be helpful in improving your photographs.

If you are shooting outside in moonlight or in a place where light is not sufficient, then you should increase your shutter speed to admit sufficient amount of light to camera which will make image more clear. If you are shooting in broad daylight or in more than sufficient light, then you should decrease your shutter speed otherwise your image will be very bright.
You should capture high speed motion in the fastest shutter speed that your camera provides.
 Lowering your shutter speed can create blur effect to show motion (which is sometimes very good).
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ISO in Digital Cameras - Introduction

Posted by gajini on 5:59 AM comments (0)

Most of the Digital Camera users don't know about ISO or are confused and many who know don't care about it and leave it on "Auto Mode" so that camera can automatically adjust settings according to conditions. But digital cameras don't take correct decision at all times and also sometimes they are very easily fooled by the light conditions and then your image go underexposed or overexposed or blurred.

ISO can really improve quality of images if used correctly. At first, you might face some difficulties in changing the ISO settings according to condition but with some practice you can master it and then it will all be very easy and in no time you can improve your photography skills.

ISO

ISO is related to sensitivity of image sensor. It defines how sensitive your image sensor is sensitive to light. If you decrease the ISO value, then your sensitivity of the sensor will decrease and vice-versa. If you are photographing in broad daylight or in a place where there more than sufficient light and your image is overexposed then, you can try lowering ISO number which will make you camera sensor less sensitive to light or you can try increasing ISO number in darker places which will make your camera sensor more sensitive to light which can be helpful in darker places.
digital camera pic ISO 80
The above image is taken at ISO 80 under a light bulb (not sufficient light).

Digital camera pic ISO 400
The above image was taken at ISO 400 under same light conditions.

Changing the ISO is useful in low light situations or to get the best quality images. Dropping the ISO number to least possible value, say, ISO 80 will get the best quality out of the sensor. However, this requires a well lit up scene and is best for studio light setups or broad daylight. On other hand, for darker places, increasing the ISO number will help but images sometimes turn out grainy. For best results in such cases, a good balance between ISO, aperture size and shutter speed is required.

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Problem in playing a video file? Find the missing codec

Posted by gajini on 10:02 AM comments (0)

A codec is a technique (compression algorithm) used to reduce the size of a video file. When a video is coded with specific codec and it is not present or properly installed on user's machine, the video won't play at all, or it won't play properly.


To help solve this, you can use one of these codec analysis tools:-

1. VideoInspector:- Analyses most containers (AVI, Matroska, MPEG and more) and gives download link for the missing codecs.

2. Gspot:- A pioneer in troubleshooting video applications, Gspotr is a very useful tool despite being lacking in some features.

3. MediaInfo:- An open source alternative to Gspot.

4. AVICodec:- A useful application mainly for the AVI container format.

The above mentioned software can be downloaded and run to analyse a video file. However, some caution serves well while installing any codec, since certain ones are known to be incompatibilities with some media players.

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Beginner's guide to different video formats

Posted by gajini on 10:58 PM comments (0)



Before knowing some video editing or digital photography tips one should have some basic information about popular formats in which a video can be recorded and distributed.

Here's a low-down on all Format jargon you are likely to encounter.

RECORDING FORMATS

1. DV (Digital Video)
The DV format is the video format standard used by MiniDV tapes. It supports uncomplicated editing, transfer over FireWire, and better quality video than the earlier analouge formats.

The raw DV data stream can be transferred over FireWire to a PC using software such as Windows Movie Maker. A 60-minute MiniDV tape is about 13-14 GB in size and takes about an hour to transfer. The files are stored in .dv and .dif extensions. However, most Windows-based programs do not support direct DV playback. But QuickTime Player, VLC Media Player and Mplayer supports direct DV playback.

2. MPEG (Motion Pictures Expert Group)
The MPEG standards define various video and audio encoding standards. Depending on the media type, video recording is recorded in one of the three defined standards: MPEG 1, MPEG2, MPEG4.

Camcorder recording media and their associated encoding scheme are as follows:-

MicroDV - MPEG2
DVD-R, DVD-RW, DVD RAM - MPEG2
Flash Memory - MPEG1, MPEG2 or MPEG4

3. High Definition (HDTV)
High Definition TV (HDTV) offers very high quality picture resolution and colour fidelity while supporting the movie theatre style aspect ratio of 16:9 compared to the 4:3 ratio of normal TV.

HD video camcorders record onto the same MiniDV tapes as standard video, but use entirely seperate video compression technology. But there is a drawback also. Editing a HD video is much more complex. To overcome this problem, high-end video editing softwares now support conversion of HD video into an intermidiate format for editing purposes.

Distribution Formats

Once you've recorded your video you can distribute it in any of the formats discussed belowdepending on the distribution media, resolution quality, as well as the size of the resulting video file.

1. AVI (Audio Video Interleave)
AVI is not a format, but rather, a container framework. This means AVI can "contain" other video codecs. This is one of the oldest video container formats and supports nearly all available video codecs.

There is a strong support for this format especially in filesharing communities due to its compatibility with Windows Media Player.

2. ASF (Advanced Systems Format)
Similar to AVI, ASF is also a container format and can be encoded with virtually any of the available video codecs. ASF is positioned as successor to AVI. ASF is ideal for streaming videos.

3. QuickTime (MOV)
MOV or QuickTime is also a container format that can contain specific codecs including the DV codec. QuickTime has an ability to seperate audio/video data from metadata such as track lists, subtitles, etc. This makes it very amenable to editing. To create QuickTime movies you need the QuickTime Pro video editing software. .mov files can be played using the QuickTRime player which is available as a free download.

4. WMV (Windows Media Video)
It is usually packed in an ASF container, especially for distribution over Internet. It also supports High Definition Video encoding onto standard DVDs in a format known as WMV HD.

5. MPEG (Motion Pictures Expert Group)
MPEG 1 - Originally designed to achieve video quality equivalent to VHS, this is one of the most compatible formats being supported by almost all computers and VCD/DVD players.

MPEG 2 - It is used to encode video and audio for variety of distribution channels including direct broadcast satellite , cable TV.

MPEG 4 - It supports all the features of MPEG 1 & 2 and have some other features also. QuickTime and Ipod video are some of the popular systems that use MPEG 4.

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