Why is the file size reduced so much?

[meganhurtphotography]

Hi, I'm using a Canon Mark II and shooting in raw. I view the image in bridge, then open it in the raw editing plugin that comes with photoshop. After I adjust what I want in the plugin, I open it in photoshop and save as a Jpeg with a 10 quality (That's what number WHCC tells me to save it as). But I've just noticed that the image goes from a 22 megapixels to a 2 megapixels after this process. I don't know why the MP is so low, and how do I keep it big but still in jpeg for when I want to print large prints? 2MP just seems really low to me considering it started at 22.
Thanks, Megan

[IABoomer]

I'm going to assume you mean MB (megabytes) not MP (megapixels) since you're talking about file sizes.

RAW files are, as their name implies, the full raw data from the sensor. There's (typically) no compression to this data, so that makes the files really big in terms of MB.

Once you export to JPEG, you're using a compression system which keeps the majority of pixel data, but not all of it. The file will still have the same dimensions (4000x3000, for example), but the way the content of each pixel is stored is different. That's why JPEG files might only be 2 MB compressed.

You should still be able to make large prints from the JPEGs. If you're trying to eke out the very last bit of goodness from an image, you might check with the printer to see if they will take uncompressed images like TIFF files.

[jdepould]

^ what boomer said.

On a totally unrelated note, maternity is misspelled on your home page.

[meganhurtphotography]

Oh and I did mean megabytes... and thanks for the catch!