Confusion over megapixels vs. megabytes

The size of a digital image in megapixels is purely the number of pixels composing the image, ie X pixels wide by Y pixels high. The quantities in Megabytes are Picture (Image) File sizes - the size of the file will depend upon the Picture Quality setting you have on the camera, and the format that the camera takes the pictures in. So-called RAW images are unprocessed and contain the maximum possible picture information - the image files are therefore very large. Some pictures are internally processed in the camera to provide TIFF or JPEG image files, for example. TIFF stands for Tagged Image File Format, an attempt at an Industry standard. TIFF files may be compressed using Lossless Compression, to reduce the file size somewhat. TIFF files may also contain JPEG files! JPEG stands for the Joint Photographics Experts Group - JPEG image files may be compressed to varying degrees to reduce their overall size.

John, I to have just purchased a 14.1 megapixel camera for my wife. Don't be too confused as pixels in a digital camera applies to the quality and sharpness of the picture you have taken. If your camera is like mine you can also change the size of the megapixels 14.1, 12.1, 10, etc. The lower the megapixel of the shot you take the less sharpness and quality, although not significantly. Megabytes refer to the size of the snapshot and does not convert to megapixels except that the higher the megapixels the greater the megabytes. You surely do not want to have photos with a megabyte size of 14. This would eat up memory in your computer rapidly and make them almost impossible to download and e-mail.
Doug G

hello lee,
well,u just have to understand that megapixels and megabytes are both completely differemt things.a pixel refers to a dot in a million.so a photo with 1 megapixel indicates that that photo is made up of 1 million dots.14 megapixel indicates it is comprised of 14 million dots(giving it better quality).megabytes refesr to memoey storage i.e. the amount of space taken in the memory to store your information or in this case,the photograph.so,dont worry taht your 14 mp camera takes pics for just 1.8 megs.its still as good as it is .it has better imaging techinques tha your old kodak

Lee,

Somewhere in the setting of your camera is a place to set the resolution of the pictures you are taking. The higher the resolution, the larger the size of the picture file saved. I went to the Nikon website and looked at the technical specs for your camera. They are:

4320 x 3240 (14M)
3264 x 2448 (8M)
2592 x 1944 (5M)
2048 x 1536 (3M)
1024 x 768 (PC)
640 x 480 (VGA)
4224 x 2376 (16:9)

You are going to have to read the manual and find that setting. If all else fails, call Nikon tech support.

John,
Megapixels is the measurement of how many thousands (Mega) of pixels is in the CMOS sensor that the camera uses to take the picture. It is more complicated than that. But for this discussion, that's all you need to know. Megabyte is the size of the picture as in taking up space on your SD card or hard drive.
Here is how to take the largest photos possible. Look in you Nikon's user manual. Find how to change the size of the photo you're taking and change it to the largest setting possible. Then find out how to change the quality settings on your camera. You want to change that setting to the highest quality setting possible. You should see a difference in the Megabyte size of your photos.
Also here are some things that can make a big difference. The more colors that are in the picture the larger the size the picture will be. Say you take a sunset photo, it will be a larger size in Megabytes than if you took a photo of anowy mountains on a cloudy day. Also try keeping your ISO setting down at 100 or 200. And use your camera set on shutter or aperature priority instead of totally automatic. I have learned by doing that using the camera on automatic will usually result in smaller Megabyte photos. But in any case, if your camera is 14 Megapixels, then all of those megapixels are being used to take the picture. It is the other things I've described that contribute to Megabyte size. I hope this helps you to understand the digital camera a little better.

Hi John M,
You have purchased a Nikon camera with an instruction manual. If you read the manual all will become clear.
br Dave

The following specs on the size of the processed image to a JPEG come directly from the Nikon website: 4320x3240 (14M), 3264x2448 (8M), 2592x1944 (5M), 2048x1536 (3M).

The number in the parenthesis (e.g., 14M) is the size of a file captured when the preceeding size (e.g., 4320x3240) of the image is chosen. Not owning that camera, I can't tell you how to change to those various sizes of image capture, but it is usually done via a menu.

Without getting too 'geeky,' the number of pixels captured by the sensor in a digital camera like those above (14M), is subject to many variables caused to the settings in your camera, each of which will reduce the number of pixels in the file you copy to your computer.

The 1st variable is the size of the image in pixels listed above--the larger you set the pixel capture size to be (4320x3240 vs 2048x1536), the more pixels are available at the time of capture.

Next is the amount of JPEG compression you have set in your camera. This is usually something like Super Fine, Fine and standard. These refer to how much the image will be compressed after it is captured, in the process of creating a JPEG image.

If the RAW image before processing into a JPEG were 'dumped' directly onto the memory card, it should contain about the same number of pixels as in Nikon's chart info shown above (14M).

If that same RAW image data is 'developed' or 'processed' in-camera with the camera's settings for size, amount of compression, white balance, sharpening, color space, etc., as it is in most point and shoot cameras, the size of the resultant image available to your computer will be dramatically reduced. Reduced file size is a good thing and a bad thing.

The 'good' is, the images can be dramatically smaller, thereby taking up less room on the memory card and your computer's disk drive, are easier to send via email, and if they were captured properly, they will be perfectly usable for most purposes.

The 'bad' is, in order to make them smaller, the algorithim for creating a JPEG image (developed by the Joint Photographic Expert's Group hense JPEG) literally requires throwing away both pixels and color information, resulting in a less than possible printed result.

A few models of each manufacturer's line-up can capture in RAW and save the information on the memory card without any lose due to in-camera processing. As a professional photographer, every image I capture is in the RAW format--not only my professional cameras, but even my 2 point & shoot models--a Canon G10 and a Canon S95.

Capturing in RAW is analogous to capturing an image on film and later developing and printing from that negative. The size, amount of compression, white balance, sharpening, color space, etc., are not changed in-camera, so they can be manipulated and 'tweeked' in software running on your computer.

Capturing in JPEG format as most P&S cameras do, is anagolous to taking a photo on a Polaroid camera--once the image is captured and processed, there is little room for 'tweeking' after the fact.

Summary: change the settings in your camera to the largest image size possible, in the super fine compression mode, and you will have the most information in each image file as is possible. Better yet, buy a Nikon camera which allows RAW capture.

First of all, it's impossible to have a 14MB image even if you set your camera to 14.2MP.

Although your camera can take pictures up to 14.2MP, it is probably set to only 5MP which is why you are only producing pictures about 1.8MP in size. You need to find the settings to choose 14.2MP.

I checked my 14.2MP Sony Cybershot camera and here are roughly the file sizes that I get at different megapixels:
14MP -> 3-5MB
11MP -> 2-3MB
10MP -> 2MB
5MP -> 1.5MB
2MP -> 0.6MB

Note that the big variation in file size of higher resolution pictures depend on the complexity of the subject and background. It doesn't vary much at lower resolutions.

Aside from the wealth of technical info above, there are only a few practical things you need to know about MP and megabytes.

Your question is somewhat odd, but I guess the underlying motivation behind your question is how to get better image quality.

You need more MP only if you do large prints or need to photograph something with very fine details. Having more MP on a compact camera is not a good thing because it increases noise level in low lighting conditions (esp when high ISO is used). You camera has more than enough MP, perhaps too many on a compact camera. So for good photo effect, make sure you have enough lighting, avoid using high ISO if possible (try to keep below ISO 400), use flash or external lighting in low ambient lighting situations.

As many have pointed out, JPEG has high compression and so end up with smaller files. On the other hand, higher end cameras have the option of RAW or other less compressed formats with larger file size. Less compressed formats give you more room to process the images with less loss of quality and details. One example will be the RAW format will allow you to correct wrong exposures or adjust color temperature much better than JPEG. But if you don't like to process your own photos, or only do the minimal cropping and red eye fix, then there is not a lot of advantage using less compressed formats. To make it simple, you should pick the highest quality format from your camera setting (or choose RAW if available, but you will need to process your photos). And remember that each time you save a JPEG file, there is some loss of quality and details, so avoid repeatedly saving a JPEG file too many times. And always edit a copy of your JPEG file instead of using the original. If you use Photoshop, use layers to do the editing.

No matter what camera you use, how much MP or megabytes your camera have, there is nothing better than good photographic technique. You should spend some time learning about lighting, exposure, color temperature (white balance), aperture/shutter control, etc. Spending time learning good photographic techniques will benefit you much more than torturing yourself to undertand the technical details and geek jargons. Photography is an art, which exist before the digital age. The basic principles of good photography has not changed. Having some technical knowledge is good but don't fret over it.

What format are you savubg images in?

TIFF will give you a very large image. On a 14MP camera a few images would use up your dstorage. JPEG compresses images. The default is usualy mild loss-less compression. 14MP will be about 1 Megabyte. Change it if you require better storage usage. Changing to TIFF RAW will usually speed the camera system up a bit as it doesn't have to compress the images.

A 14MP picture could take up to 100Mb to store. (That is Mega-BYTES not Mega-BITS) A 4Gb flash will hold about 35 100Mb pictures or about 3900 1 Mb pictures.

The pixels are the "dots" that make up the image. A kilopixel is nominally 1000 pixels. A megapixel is nominally 1000 kilopixels, or one million pixels. 14.2 megapixels is 14.2 million pixels in the image.

Each pixel contains data, and that data is stored in bits. Eight bits equals one byte. A kilobyte is 1024 bytes (1024 = 8x2 8 times). A megabyte is 1024 kilobytes, or 1,048,576 kilobytes.

So pixels relate to the physical image size on screen, while bytes relate to the image file size on disk. The two are always different

A typical 24 bit colour, 14.2 megapixel, lossless compresed RAW image file is about 20 megabytes. However, if it is in JPEG format is will be compressed by discarding data (irretrievably) and the compressed file size will depend on the level of compression - the higher the compression the lower the quality, and vice versa. It could be considerably smaller than the RAW file size depending on the

You can see that megapixels and megabytes are two different things and the relationship between them is variable. The prefixes "kilo" and "mega" are used frequently in all sorts of measurements. For example, megawatts, megavolts, megatons, megabytes, kilogrammes, kilopascals, kilometres, kilowatts, kilobytes. Their usage signifies millions and thousands respectively, and it's perfectly correct.

Megapixels (MP) of a cemera are not directly related to the Megabytes (MB) or file size of the image. Thus 8 MP camera will not take a 8 MB photo, it just doesn't work that way.
Most digital camera allow for you to take images at different sizes & qualities (S,M,L & Basic, Normal, Fine & Raw) The S,M,L refers to size of the image (800x1,000 pixels) Where quality refers to the number of pixels per image (6, 8 or 10MP). The larger the size & higher the quality equals a larger file. Though each image you take at any setting will not be the same size. (You can take 5 different pictures at the same settings & each image would have a different file size (MB) It has to do with the amount of data (detail) in the images.
In short the answer to your question. First check the settings of your camera. If your camera is set to Basic or Normal you are not using all of your Megapixels and unless you plan on making large prints there is little need to. If you simple post most of your images online there is no need to either b/c most online photo albums resize the image any way & if they don't and you have a limited a limited amount of storage space you will reach your limit that much faster. Not to mention the average monitor is only 72 dpi, so if you have an image that is 3x5" but at 300 dpi it will apear much larger on a monitor.
There is much more to it, but that is the short of it all. Good luck & enjoy your new camera.

Megapixels refer to the product of the length x width in pixels in a photo

megabytes refer to the space, volume, or bandwidth occupied by a digital file.

They both are digital, meaning the arithmetic is computed using powers of 2 (i.e. 0, 1, yes, no, Boolean arithmetic) but they represent entirely different entities. Yes, megapixels are stored as digital files measured in megabytes but megapixels are a strictly mathematical product of length x width.

Hi John,

The easy way to understand this is:-

Mega-pixel = The size of the page.
Mega-byte = The thickness of the book.

Mike.

Hello,

this is oly because the picture is in JPG compressed format.
The ratio between the ative resolution in Megapixels and the file size in Megabytes depends on the compression settings.
The smaller the file, the larger the compression ratio.
JPG is a lossy compression algorithm.
Higher compression setting implies more data loss.
Owever the picture could not be as darker as it would (I'm not sure that this sentence makes sense in English :S)because the native sensor resolution is far away from being the only thing to take into account.
Another very important key point is the lens optical resolution, and as far as this feature is concerned, compact cameras are most of time fit with medium to low resolution lenses.
Using RAW format is an alternative, but it makes sense only when we're talking about reflex cameras with high optical resolution lenses. It's a nonsense to talk about RAW format with compact cameras.

The pictures made by the camera are generally stored in the working-memory first in raw format. At that time the picture may take even more memory to store the real color. Professional cameras allow to export the pictures in this, lossless format. However, to allow to make more pictures, they generally - as the second step - convert them into a compressed format (jpg or other), which results slightly worse quality, but much less size in bytes. In an amateur-usage that doesn't matter, but if you want to use it to make large-size prints, you may need the raw-format. Cheaper cameras doesn't store raw format at all, they immediately compress it to jpg.

One million pixels, refers to the resolution of a digital imaging device (monitor, scanner, video camera, still camera, etc.). For example, a five-megapixel still camera captures a picture composed of 5,038,848 pixels, each pixel containing a red, green and blue color dot. Such an image would have a 2592x1944 resolution: 2,592 pixels across, 1,944 pixels down.

It's pretty simple. Mega = million, Pixel = individual dot of image, Byte = 8 digital bit hunk of data. Your new camera has 14.2 million dot positions, (pixels) on the sensor. Early PCs were 8 bit machines, meaning they worked with 8 bit or 1 byte (or 2 nibble as 1 nibble =4 bits of data)) words of data, Today PCs work with 32 and 64 bit words or 4 & 8 byte words. When your camera takes a picture it processes it into and saves it as a file. The file size will vary with the details of the image. That's because it usually saves it as a compressed file, usually a jpeg file (file extension =.jpg). Essentially that means the file records the details of all identical "dots" in the image as a single entry in a lookup table in the file with the lookup table entry # recorded for each identical dot position in the image. That uses less bytes of data than separately recording all the details of the dot(s)for each dot position. The more different smaller bunches of identical dots in an image, the bigger the file it'll be saved as. The fewer bunches of identical dots in the image the smaller the file.
All file sizes are referred to in bytes (or megabytes = million bytes) of data.
So it boils down to Megapixels = the # of dots in the picture and Megabytes = the # of "bytes" of data in the file the camera records the image as.

Demystifying Megapixels, Resolution, photo size, photo megabyte


There are some common words you will see again and again as you delve into digital photography; Megapixel, Resolution and DPI megabyte.
What do each of these mean?

Megapixels

Megapixel basically means one million pixels. A pixel is a small dot that contains a piece of your finished picture, similar to a puzzle piece. When you put each of these pixels together, they form a picture. Like the picture of marigolds above, you can see that the first one is clear. In the second picture, we have shown how it is formed of millions of tiny pixels. Our eyes process an image as a whole, where as a computer and a digital camera break each image up into pixels.

The more megapixels per image, the clearer and sharper it becomes. Digital cameras today range anywhere from 2 megapixels to 20 megapixels for each picture taken.

These settings will affect the quality of your image and the file size of each image.

Resolution

Resolution refers to the size of the image that your camera will produce. This is normally referred to as megapixels, which we discussed above. You will normally see cameras advertised as having a 1600 x 1200 resolution. To figure out the amount of megapixels that will give you, you multiply the dimensions. For example:

1600 times 1200 = 1.92 million pixels or 1.92 Megapixels. This would commonly be rounded up and referred to as a 2 megapixel camera.

As this amount goes higher, you will notice a much sharper image. We have provided the following examples below. Please look closely at them and you will be able to see the difference each level makes.

1024 x 768 resolution = .78 megapixels

1839 x 1461 resolution = 2.61 megapixels

3200 x 2400 resolution = 7.8 megapixels

DPI - Dots Per Inch

DPI means Dots Per Inch. This is what your printer will recognize when it prints your image. Your computer monitor is configured to view items at PPI, or Pixels Per Inch. This can cause a great disparity when trying to get what looks like a great image on your screen to come out looking just as good on your printer.

An image that has 72 PPI will look fine on your monitor. Each inch of the image will contain 72 pixels. However, when you print that image, it will not be as clear. In fact, it may look choppy and distorted. When you print an image, it will be sized at approximately 25% of what you see on your screen. You will need to have a larger PPI in order to get a printed photograph that is true to size.

The best way to get a true print is to have your image sized at 300 DPI. This will ensure that your image will be the correct size when you print it.

Print Sizes

So what does this all mean in the final analysis? In order to get the best finished product, you will need to have a higher resolution, more megapixels and a high DPI. Unfortunately, this also means extremely large files and very large prints. How can you estimate the size of your images before you are ready to print?

Here is an easy reference guide to get you started:


Final Print Size Megapixels Image Size on Monitor
2.1" x 1.6" 0.3 640 x 480
4.25" x 3.2" 1.2 1280 x 960
5.3" x 4" 2.0 1600 x 1200
6.8" x 5.1" 3.0 2048 x 1536
10" x 6.5" 5.3 3008 x 1960
10.25" x 6.8" 6.3 3088 x 2056
13.5" x 9" 11.1 4064 x 2704

As you can see, if you wish to get an 8 x 10 print of a certain shot, you will need to have a higher megapixel amount to achieve good results. Otherwise, your finished print will have a coarse, or grainy look to it, instead of being a sharp image.

Each pixel of a megapixel camera is in fact a minute sensor and together they make up the charge couple device or CCD chip in your camera which captures the picture.
To capture and reproduce a color image, a way of measuring the specific amounts of red, green and blue that make up each segment or pixel of a scene is needed.
Knowing the exact amount of each primary color (red, green and blue) that makes up EVERY pixel segment of a scene allows the camera and computer to construct a full color image from a pallet of 16.7 million color possibilities. (More on this later.)
To separate and measure the amounts of red, green and blue in each element of the picture, most digital camera manufacturers place a Bayer filter array over the CCD sensor array with each sensor covered by a block of 4 colored filters two green one red and one blue. Each transparent red, green or blue filter allows only its own color to pass through and strike the picture element or pixel below. In this way, red, green and blue light components are segregated and recorded.
You will notice that there are two green for every one red and one blue filter per sensor, this is due to the human eye's bias for the color green. Our eyes are most sensitive to the color green. So to mimic our eyes and provide a bias to the color and intensity of light in the scene, camera manufacturers use 2 green filters to every 1 red and blue.

The color information gathered at each sensor is translated into a digital color code for each pixel. This code describes the color of that pixel in terms of an intensity of red, an intensity of green and an intensity of blue. Each color (r,g and b) has an intensity scale range of 0 to 255. So a specific pixel color code would look something like this red 102, green 153 and blue 204. This description is very specific color of blue and when you consider the number of possibilities with a range of 256 for each color. That's 256 times 256 times 256. Doing the math yields 16,777,216 possible colors at each pixel site -- usually rounded off in "photo-speak" to 16 million colors. The "number crunching" that takes place inside your camera is mind blowing when you consider 16 million possible colors at each of the millions of pixel locations on the sensor.

Note: Absolute photographic black is described as 0, 0, 0 -- no red, green or blue recorded. While pure white is assigned the values of 255, 255, 255 -- maximum and equal amounts of red, green and blue. Anytime the three colors are assigned the same numbers (e.g., 110, 110, 110) a shade of gray is the visual result.
These values are recorded by the camera as 8-bit values one 8-bit (or 1 byte) value for each red, green and blue, that hits a sensor or pixel

Megapixels make sense, but how does that relate to the size of the image file stored on the camera's data card?

These 3 digit values which describe the amount of red green and blue hitting each sensor or pixel are recorded by the camera as 3 bytes of data per sensor, one for red one for green and one for blue, the final image file size will therefore be three times the total number of sensors or megapixels used in your camera's CCD chip to record a picture scene.
In terms of a 10 megapixel camera, the final image file would be 30 megabytes in size (3 bytes per pixel x 10,000,000 pixel locations). This file size represents the UNCOMPRESSED information provided by combining the inputs from all the pixels on your camera's sensor.

Note: Technically, not all pixels on a camera's sensor are used to collect color information. Some serve other purposes in the recording process. So the 30 megabyte calculation above is approximate. You will often see two separate megapixel counts given for a specific camera's sensor. The first number is the actual number of pixels contained on the sensor, while the second is called the "effective" number of pixels. The second number (effective) is more representative of the number of pixels being used to measure and record the scene. Multiplying the "effective" number of pixels by 3 is closer to the actual uncompressed file size produced during exposure.

This is an important distinction because some form of compression will take place when you save the file. Saving files using the JPEG option on your camera compresses this data to save storage space. Depending on the amount of JPEG compression you specify (for example, "fine", "normal" and "basic" choices on a Nikon DSLR) the final file size will be progressively smaller. But when these files are opened on your computer, they will be expanded to the full, original rendition megabyte size of your image.

Here is the run down, megapixels is totally different than megabytes! megapixels is all those little squares on your computer monitor, that you can only see when you get very close to the screen, Megabytes is data, and how it is counted! No matter what size photo you take will match up the amount of data(megabytes)that will take up on your hard drive. Now what everybody else on this forum are talking about is compression some audio and video formats, take up more data(megabytes) then other formats. But will still not make megabytes and pixels the same! Alright I hope your not PUZZELED ANYMORE. Take care, and GOOD LUCK.

Hiya!

You've been swindled!

Hah! No, not really. You have a great camera.

I kinda would like one myself ;o)
The very simle reason is that you have your image size set very low.

Your Nikon 5600 has a setting to adjust the image size in pixels. The smaller the numbers the smaller the file size.
I'ma thinking you have your image size set to 1024x768. That's okay for computer-lookin' -at, but not for printing larger than (maybe) 3x5 inches.
That's what Nikon terms "PC" as in PC computer monitors. Set your image size to 4320x3240 and each picture will be about 14MB... great for making 20x30 inch posters of your cat hugging your dog.

Here's a rundown of your image settings:
(probably all .jpg, except the 14MB size, which might be .tiff - don't know, just supposing)
4320 x 3240 (14M)
3264 x 2448 (8M)
2592 x 1944 (5M)
2048 x 1536 (3M)
1024 x 768 (PC)
640 x 480 (VGA)
4224 x 2376 (16:9)

Holy Hat! You can take MOVIES at 30frames per second! In HD!!! )and smaller, too)
Movie file format: MPEG-4 AVC H.264
Audio file format: AAC stereo
HD: 1280x720p / 30fps
Standard TV: 640x480 / 30fps
Small Size: 320x240 / 30fps

It's great camera that you can carry everywhere!

Lets get a little scientific here and compare mass with volume: Two blocks, one sponge and one copper, of the same size we know they do not weight the same; the copper weighs heavier than the sponge but if you try both in a container they occupy the same amount of space. Now assume that you had half the size of the sponge as your block of copper, I can bet that the copper block would still weigh heavier. This is because in terms of "mass" copper has more than the sponge even at have size in volume. So now lets assume that your megapixels are a block of copper and your megabytes are the block of sponge. So we assume that pixels are in terms of mass and bytes in terms of volume. I hope this helps a little.

This (pretty wonderful) thread is getting out of hand.
Can we bring it down to Point 1: are we interested in shooting a great photo? Or Point 2: are we going to get all posey about megapixels?

Anybody who wants to follow Point 1 needs to read a manual about how to take photographs: which involves choice of lens, choice of zoom level, selection of light source, awareness of camera-shake - like old fashioned stuff which is true for a Leica II as much as for the latest digi Nikon.

However, if you are simply following the 'computer' press, you can be seduced into believing that megamissino pixels will make you into Cartier Bresson. They won't.

not entirely related to your question, this link provides a useful calculator for scan & print / display resolutions:

http://www.scantips.com/calc.html

I'm sure I once read that the camera receptor size affected the number of megapixels captured which produced a given picture file size - ie the bigger the receptor the more megapixels you need to produce a given file size. As the manufacturers offer bigger receptors you need more pixels to get the same file size.
andy

Pixels if for quality of pictures. The higher the pixel the more clearer and smooth the image gets. Bytes are for capacity of a hard disk.