Photo Megpix Question?

I have WORKED MY BUTT OFF getting shots to submit for some various contests. I don't have money for an expensive camera. I am using a Kodak z812IS this is an 8 megapixl camera w/ 12 times optical zoom Schnieder Kreuznauch lens
I keep it set at the highest quality - of 8 Megs.
The contest stipulates the original photo has to be at least 3 Megs. Seems like that should be just fine with an 8m camera set to the highest quality.
I still have shots in the camera. When I REVIEW the photos IN the camera - and look at SIZE it says 8 M - or thereabouts.( it has them as JPEG this camera does not do RAW)
HOWEVER-when I download them and go to view them in Photoshop. THERE THE SIZE Says 1meg or 2 megs etc. Tight shots of faces, etc say under 1M even tho they totaly fill the frame.
Is it the case that virtually NONE of my photos qualify since they show under 3 megs? Or did that just mean that it has to be taken with a camera that is at least a 3Megapixel camera?
Please help !

Megapixels is not directly related to file size when compression is used. Furthermore, Jpeg is a lossy compression so file sizes will be even more unpredictable. In RAW or uncompressed TIFF formats, there is a more direct relationship between megapix and file size. In fact, uncompress images are about 3 times the megapixels in mega-bytes. That means your 8Mpixel camera would generate a 24MB uncompressed TIFF. Not to worry. If you contest stipulates megapixels and allows jpeg submissions, you should be good to go. Don't worry about the file size. I would suggest you use the lowest compression setting your camera allows (usually designated as "Fine" mode or some such).

OK, there are Megapixels and Megabytes. The two are totally unrelated. JPEG is a format that compresses the size of the image by using formulas to eliminate the data.

For instance, if a tight shot of the face, much of the skin is probably alike, and thus the data does not need to be duplicated for every pixel after being compressed.

The real question is this. If the contest stating that the original photo must be at least 3 megapixels or at least 3 megabytes?

The file size has to be 3 MB or larger.

8MP is a pixel count ... when you say you keep the camera at 8 megs, do you mean that the image files are actually 8MB? Unless you are shooting in RAW (which you camera does not support) the largest image file you may be producing while might be over 3MB (megabytes not MegaPixels) the only way to know for sure it to look at the file size using your file manager. One of the things that affects the size of the file, has to do with many things, including the quality of the analog to digital converter electronics.

Your last sentence shows that you have Megapixels confused with megabytes. Google them and see what you learn.

My 12MP camera produces 6MB JPEG/11MB RAW files
My 10MP camera produces 4MB JPEG/9MB RAW files
These are average file sizes because they very on the number of blue pixels stimulated during each shot.
They are both DLSR's, so the individual pixels are going to be larger than ones on P&S sensors that are about 15 times smaller than a DLSR's

You have a nice camera and lens combo, however you are getting a tad confused between mega-pixels (the size of the chip IN the camera) and mega-bytes, the size of the file the camera can produce, it's picture...

In your camera's Menu, under Setup you should have the ability to switch from Jpg to Tiff. Tiff will give you very large files because there is no compression, as in a jpg. However, there should also be a 'size' setting too. How they word it I don't know for I don't have that camera in front of me, however it may be quoted in size - 3000x2000 or 2000x1200 and down or something like that, or they may use Large. Medium and Small. In the JPG setting you often have compression levels using the same - Fine, Medium and so forth. Always pick the Fine setting for compression.

Jpg Fine is the least compressed but your actual file size will be 2.5 to 3.5 mega-bytes when the camera is set for the 'largest' image, in the 8mega-pixel mode. JPG's compress strangely and the less color and or detail (or both) the image file can be quite small. That's why just a close up of a face will be a smaller file than a full body shot.

I really believe your requirements are being met because the requirements for the contest refer to the chip size of the camera, with 3 mega-pixels being the smallest they want for quality. I would make sure ALL my camera settings are set to deliver the least amount of compression, if shooting JPG's, or if you have a Tiff mode to think about shooting there if making prints. The jpg Fine can and will make good prints, but it is also a function of the printer interface (the program) and some do a better job than others.

My "newest" D-SLR is almost always shot in the '6 mega-pixel' mode and it and the older ones I have are able to do 16x20's and 20x24's that look - real good and most of the time I'm in JPG Fine. For printing I use a program called Qimage and I print on a Epson 7600 wide format printer. In RAW they really shine and I use Adobe Lightroom for the RAW processing and convert to Tiff's..