Megapixels

[tragiccomic]

I have a Canon EOS Rebel 1000D and it is 10 megapixels. I took some outdoor scenic photos and uploaded them to a website. The website requires that the photos have at least 4 megapixels. I was told that my photos have less than 4 megapixels. If my camera has 10 megapixels does that mean that my pictures  will automatically have 10 megapixels or does it depend on the individual photo itself? Having trouble with the whole megapixel thing and hope someone can explain.

Thanks,

Amy

[hsbn]

Depend on the image settings, photos can be less than 10Mpx. What is the image setting on your camera? What's the JPG size?

[hsbn]

Here are some JPG settings on your camera:
(1) Large/Fine :
3888 x 2592 pixels ~ 10Mpx
(2) Large/Normal :
3888 x 2592 pixels
(3) Medium/Fine :
2816 x 1880 pixels ~ 5Mpx
(4) Medium/Normal:
2816 x 1880 pixels
(5) Small/Fine :
1936 x 1288 pixels ~ 2.5Mpx
(6) Small/Normal :
1936 x 1288
So if your image setting is small then your photo will only have 2.5Mpx which is less than the 4Mpx requirement that you need. All of this assuming you don't crop your image after capture also.

[ebiggs1]

A web site said you need 4 MP file size?  I find that odd.  4 MP form a cell phone is not the same as 4 MP from a EOS 1D.

Although each may have the required 4 MP, they would not even be comparable.

[Skirball]

It's also possible that you used a program for post processing and inadvertantly downsized on export.

The Megapixel thing is pretty simple, sorta.  The sensor in a digital camera is made up of an array of millions of little wells that capture photons and count them.  Each one of these equates to a pixel on the screen when viewed at full size.  The total amount of all these wells is know as the camera's resolution.  Your camera's sensor is 3888 wells wide by 2592 wells high, for a total of 10 million+ pixels, maximum. 

Although computer monitors continue to grow, the average monitor still isn't half that size.  So people downsize them to fit monitors and speed up downloading times on the internet.  There's no need to send full res files unless you plan on giving them to someone to print.  Conversely, I don't put up full sized images of mine on the internet so that others can't take them and print them without my permission.   I put up my photos on photosites and social media sites at a maximum of 1024, which in 2:3 aspect ratio is about 0.7 megs.  Plenty for the internet.   Compressed they can be half that size.   I'm not sure what website you're working with, but I'd think twice if anyone told me that I have to submit pictures that are 4 MP or larger.