gazaly
05-02-2007, 09:45 AM
What is Megapixel?
Megapixel is a unit that measures the resolution in optical devices (i.e., the number of dots the image will have), especially in digital cameras. The value in megapixels is found by multiplying the image’s width by its height. For example, an image with resolution of 1280x1024 has resolution of 1,310,720 pixels or 1.3 megapixel. On the chart below we present the most common resolutions. As you can see, there are some close estimates: cameras with 1.9 megapixel are sold as having 2 megapixels.
http://i98.photobucket.com/albums/l252/gazaly786/cam1.jpg
The thought, “the higher the camera resolution, the best the camera quality” is a myth. It is far from being true. Image quality depends on several other factors, such as the camera lenses, the sensor that captures the image, and the processing the image goes through (every camera processes the image after capturing it in order to “fix” color levels, white balance, etc). It is easy to find cheap 3.2-megapixel cameras in the market with lower image quality than that of 2-megapixel ones made by famous manufacturers.
How Many Pictures Can I Store in One Memory Card?
A very common question for those who are willing to buy a digital camera - or just bought one and want to buy a new memory card is knowing which capacity the memory card should have.
It’s a question we can’t answer for sure, because the pictures are stored in JPEG format, which uses data compression and which final size depends on several factors. But we can have a general idea. On the table below we show the average size of a picture taken in several different resolutions and how many pictures fit in a card depending on the resolution used. Therefore, a camera with 3 megapixels with a card of 64 MB will store around 53 pictures. Notice that those values are estimate.
http://i98.photobucket.com/albums/l252/gazaly786/cam2.jpg
Most Common Terms
* Due to the great variety of options, buying a digital camera nowadays is a hard task. On the previous pages we talked about resolution and how many pictures we can store in a memory card. Below we will see the main characteristics you need to know about those equipments.
* Zoom: There are two types of zoom, optical and digital. The optical is the “real” zoom, and a program inside the camera makes the digital. In general the total zoom announced is the addition or multiplication of the two types of zoom. For example, in a camera with 3x optical zoom and 2x digital zoom, the enlargement of up to 3x is made by the camera lens itself; from then on the enlargement is made by software, where the result may be not so good.
* Red eye reduction: When on, it reduces the famous problem of some people appear with their eyes red.
* White balance: Allows you to adjust the light intensity of the scene to be pictured according to its “temperature”, if it’s using hot or cold light, correcting the light in the picture to prevent it from looking too blue or too orange. We usually can configure that option in “auto” (AWB, Auto White Balance) or according to the light used, as daylight, cloudy, fluorescent, tungsten, or flash. More advanced cameras have a manual control for that feature, where you can “teach” the camera (by taking a picture of a total white or gray card at the place to be pictured) how the light at the site is.
* CCD: It means Charge-Coupled Device and it’s the name of the technology used by the digital camera sensor in charge of converting the image, which is analog, into digital information.
* Nightframing: Allows you to see, on the camera LCD screen, the image you are about to picture, even if the place is totally dark. For that feature, it uses an infrared sensor. The picture is taken using flash and is captured as a regular picture.
* Nightshot: Allows you to take pictures in the dark without turning the flash on. In most cameras, this happens by increasing the time in which the camera shutter stays open. Sony cameras (and also digital camcorders) use the “infrared nightshot” (IR nightshot) feature, which is different but get the same name, so be careful not to mess everything up. Infrared nightshot illuminates the subject using an infrared light (sensor) and that’s why the picture is taken in black and white or gets a greenish tint, in order to provide a more accurate and realistic feeling. With this system, it’s usually possible to capture only very close subjects (up to 10 feet away).
* Flash level: in some cameras you can adjust the flash level. If the flash leaves the pictures too bright or doesn’t illuminate the subject well, you can change the adjustments and try to solve the problem.
* SLR: Means Single Lens Reflex, where you can see the image through the same lens that will take the pictures. This system is available in professional and semi-professional cameras and not available in cameras designed for the regular user.
* Histogram: Cameras with more increments count with this feature that displays through graphics on the screen the number of areas of over and under exposure your picture will have. The "x" axis in the graphic indicates the brightness (the left side means "dark" and the right side means "bright"), and the "y" axis indicates the number of pixels at that tone in the image. This feature is good for, among other things, checking out if your picture will become too bright or too dark. Through the exposure adjustment you can eventually correct this problem, that is, by making sure the graphic doesn’t get too much to the left (image too dark) nor too much to the right (image too bright).
:yes: :yes: :yes: :yes: :yes: :yes: :yes:
Megapixel is a unit that measures the resolution in optical devices (i.e., the number of dots the image will have), especially in digital cameras. The value in megapixels is found by multiplying the image’s width by its height. For example, an image with resolution of 1280x1024 has resolution of 1,310,720 pixels or 1.3 megapixel. On the chart below we present the most common resolutions. As you can see, there are some close estimates: cameras with 1.9 megapixel are sold as having 2 megapixels.
http://i98.photobucket.com/albums/l252/gazaly786/cam1.jpg
The thought, “the higher the camera resolution, the best the camera quality” is a myth. It is far from being true. Image quality depends on several other factors, such as the camera lenses, the sensor that captures the image, and the processing the image goes through (every camera processes the image after capturing it in order to “fix” color levels, white balance, etc). It is easy to find cheap 3.2-megapixel cameras in the market with lower image quality than that of 2-megapixel ones made by famous manufacturers.
How Many Pictures Can I Store in One Memory Card?
A very common question for those who are willing to buy a digital camera - or just bought one and want to buy a new memory card is knowing which capacity the memory card should have.
It’s a question we can’t answer for sure, because the pictures are stored in JPEG format, which uses data compression and which final size depends on several factors. But we can have a general idea. On the table below we show the average size of a picture taken in several different resolutions and how many pictures fit in a card depending on the resolution used. Therefore, a camera with 3 megapixels with a card of 64 MB will store around 53 pictures. Notice that those values are estimate.
http://i98.photobucket.com/albums/l252/gazaly786/cam2.jpg
Most Common Terms
* Due to the great variety of options, buying a digital camera nowadays is a hard task. On the previous pages we talked about resolution and how many pictures we can store in a memory card. Below we will see the main characteristics you need to know about those equipments.
* Zoom: There are two types of zoom, optical and digital. The optical is the “real” zoom, and a program inside the camera makes the digital. In general the total zoom announced is the addition or multiplication of the two types of zoom. For example, in a camera with 3x optical zoom and 2x digital zoom, the enlargement of up to 3x is made by the camera lens itself; from then on the enlargement is made by software, where the result may be not so good.
* Red eye reduction: When on, it reduces the famous problem of some people appear with their eyes red.
* White balance: Allows you to adjust the light intensity of the scene to be pictured according to its “temperature”, if it’s using hot or cold light, correcting the light in the picture to prevent it from looking too blue or too orange. We usually can configure that option in “auto” (AWB, Auto White Balance) or according to the light used, as daylight, cloudy, fluorescent, tungsten, or flash. More advanced cameras have a manual control for that feature, where you can “teach” the camera (by taking a picture of a total white or gray card at the place to be pictured) how the light at the site is.
* CCD: It means Charge-Coupled Device and it’s the name of the technology used by the digital camera sensor in charge of converting the image, which is analog, into digital information.
* Nightframing: Allows you to see, on the camera LCD screen, the image you are about to picture, even if the place is totally dark. For that feature, it uses an infrared sensor. The picture is taken using flash and is captured as a regular picture.
* Nightshot: Allows you to take pictures in the dark without turning the flash on. In most cameras, this happens by increasing the time in which the camera shutter stays open. Sony cameras (and also digital camcorders) use the “infrared nightshot” (IR nightshot) feature, which is different but get the same name, so be careful not to mess everything up. Infrared nightshot illuminates the subject using an infrared light (sensor) and that’s why the picture is taken in black and white or gets a greenish tint, in order to provide a more accurate and realistic feeling. With this system, it’s usually possible to capture only very close subjects (up to 10 feet away).
* Flash level: in some cameras you can adjust the flash level. If the flash leaves the pictures too bright or doesn’t illuminate the subject well, you can change the adjustments and try to solve the problem.
* SLR: Means Single Lens Reflex, where you can see the image through the same lens that will take the pictures. This system is available in professional and semi-professional cameras and not available in cameras designed for the regular user.
* Histogram: Cameras with more increments count with this feature that displays through graphics on the screen the number of areas of over and under exposure your picture will have. The "x" axis in the graphic indicates the brightness (the left side means "dark" and the right side means "bright"), and the "y" axis indicates the number of pixels at that tone in the image. This feature is good for, among other things, checking out if your picture will become too bright or too dark. Through the exposure adjustment you can eventually correct this problem, that is, by making sure the graphic doesn’t get too much to the left (image too dark) nor too much to the right (image too bright).
:yes: :yes: :yes: :yes: :yes: :yes: :yes: