Any of you gearheads know how to convert megapixels to megabites? Like If you turn out a 10 MP file, how big in MB's?

FYI: I was reading here about large digital files, 144 gigapixel. I have been turning out 65 MP files for long time. A 6x6 negitave, shot with Hasselblad is the same as a 65MP file. Digital has some ways to go to match film.

Long live film shooters!

Exposed

 

You can't really convert MP to MB directly. It depends on the file type and compression used. RAW and TIFF are lossless formats and therefore don't have compression. The file sizes are a lot larger as a result. JPEGs can have a wide range of file sizes for a given number of MP depending on the amount of compression you permit (in photoshop this is controlled by the "quality" level on a scale of 1 to 12 when you save a file).

Here are some numbers from my own experience

6 MP RAW file is about 5 MB
6 MP TIFF file is about 10 MB
6 MP JPEG can range from 4.5 MB to 800k depending on compression

I have also done interpolation on 6 MP files for printing. If you interpolate from a 6 MP file to print 16x20 you would export a 80-100 MB TIFF file.

 

David's guidelines are right. With JPEGs, you really can't say since different pictures compress better than others. Take a picture of fluffy clouds and another with lots of blades of grass using the same amount of JPEG compression on both and you'll see a big difference in file sizes.

For TIFFs, each pixel has one each of red, green, and blue values, each 8 bits (one byte), so you end up with 3 bytes per pixel or 3 megabytes per megapixel. A 10 MP picture, in TIFF format, should be 30 MB.

RAW is strange because the camera directly stores what comes off the CCD with no conversion to pixels. Almost all digital cameras store one of red, green, or blue values for each photosite and the post-process RAW converter, running on your computer, converts that to pixels with a process called de-mosaicing. At that point you end up with three bytes per pixel after the software tries to figure out what they should be but, before that, assuming 12 bits per photosite (as most DSLRs have), you end up with 1.5 bytes (12 bits) per "pixel" (photosite, actually). For example, a 10 MP uncompressed RAW file will usually be about 15 MB.

Mark

 

Along the lines of electronic photography is this interesting site about very high resolution (gigapixels) digital images and how they were produced:

http://www.tawbaware.com/maxlyons/gigapixel.htm

Rick