Megabite Size?

Bramela · 11-08-2010, 12:10 PM

A very simple question, which may be very easily answered. I have to submit a photo to a competition venue by email.

It required the stipulation that the submitted photo be no larger than 2MB.

Now, I can read size of photo by pixels on either side, and I read that the photo shows size as 10.2 Megapixels.

How do I equate this into MB measurement, if somebody could give me a hint, thanks?

Ananta Androscoggin · 11-08-2010, 12:15 PM

They're talking about the file size, as you see in your directory (or in the "Get Info" window on a Mac).

8 bits makes for 1 byte

1024 bytes makes up 1 KB -- KiloByte

1024 KB (1,048,576 bytes) makes up 1 MB -- MegaByte

1024 MB (1,048,576 KB, or an awfully lot of bytes) makes up 1 GB -- GigaByte

And I don't even want to try the math for TB or anything higher. There were once people who thought the world would never need a cumulative capacity of over 5 TB worldwide total.

Bramela · 11-08-2010, 12:23 PM

Thanks for the quick reply, Ananta. I thought it would be something very simple.

Regards.

jolepp · 11-08-2010, 12:28 PM

I would keep on saving the original under a different name decreasing the JPEG quality until it is (slightly) under the limit: there is no exact rule for converting megapixels to megabytes as the compression ratio obtained depends on the contents of the picture as a whole as well as the JPEG quality used.

Adam · 11-08-2010, 01:09 PM

It's important to note that some people make the mistake of thinking that a megabyte is 1,024,000 bytes, (1024x1000) rather than the 1,048,576 as Ananta properly pointed out (this number has become known as a mebibyte, 20^2 or 1024^2). Others have started using 1,000,000 bytes for a megabyte. Therefore, when uploading to websites, always assume the worst-case scenario and set the cutoff at 1,000,000 bytes

Here on the forum, we go by the mebibyte designation in most areas.

**boriscleto** · 11-08-2010, 01:22 PM

Originally posted by Adam

It's important to note that some people make the mistake of thinking that a megabyte is 1,024,000 bytes, (1024x1000) rather than the 1,048,576 as Ananta properly pointed out (this number has become known as a mebibyte, 20^2 or 1024^2). Others have started using 1,000,000 bytes for a megabyte. Therefore, when uploading to websites, always assume the worst-case scenario and set the cutoff at 1,000,000 bytes

Here on the forum, we go by the mebibyte designation in most areas.

1,048,576 is a megabyte only in reference to computer memory (RAM), although Microsoft continues to use it in the Windows file manager. The IEEE, SI, and IEC have decided that Mega means 1,000,000 with exceptions. Apple, as of 10.6 Snow Leopard have changed to the new definition.

Ananta Androscoggin · 11-08-2010, 02:29 PM

The world just keeps dumbing-down . . .

11-08-2010, 12:10 PM	#1
Bramela Veteran Member Join Date: Jan 2007 Location: Newcastle Australia Photos: Gallery \| Albums Posts: 5,284	Megabite Size? A very simple question, which may be very easily answered. I have to submit a photo to a competition venue by email. It required the stipulation that the submitted photo be no larger than 2MB. Now, I can read size of photo by pixels on either side, and I read that the photo shows size as 10.2 Megapixels. How do I equate this into MB measurement, if somebody could give me a hint, thanks?

11-08-2010, 01:09 PM	#5
Adam Administrator Site Webmaster Join Date: Sep 2006 Location: Arizona Photos: Gallery \| Albums Posts: 51,594	It's important to note that some people make the mistake of thinking that a megabyte is 1,024,000 bytes, (1024x1000) rather than the 1,048,576 as Ananta properly pointed out (this number has become known as a mebibyte, 20^2 or 1024^2). Others have started using 1,000,000 bytes for a megabyte. Therefore, when uploading to websites, always assume the worst-case scenario and set the cutoff at 1,000,000 bytes Here on the forum, we go by the mebibyte designation in most areas. Adam PentaxForums.com Webmaster (Site Usage Guide \| Site Help \| My Photography) PentaxForums.com server and development costs are user-supported. You can help cover these costs by donating or purchasing one of our Pentax eBooks. Or, buy your photo gear from our affiliates, Adorama, B&H Photo, KEH, or Topaz Labs, and get FREE Marketplace access - click here to see how! Trusted Pentax retailers:

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11-08-2010, 12:15 PM	#2
Ananta Androscoggin Guest	They're talking about the file size, as you see in your directory (or in the "Get Info" window on a Mac). 8 bits makes for 1 byte 1024 bytes makes up 1 KB -- KiloByte 1024 KB (1,048,576 bytes) makes up 1 MB -- MegaByte 1024 MB (1,048,576 KB, or an awfully lot of bytes) makes up 1 GB -- GigaByte And I don't even want to try the math for TB or anything higher. There were once people who thought the world would never need a cumulative capacity of over 5 TB worldwide total.

11-08-2010, 12:23 PM	#3
Bramela Veteran Member Join Date: Jan 2007 Location: Newcastle Australia Photos: Gallery \| Albums Posts: 5,284 Original Poster	Thanks for the quick reply, Ananta. I thought it would be something very simple. Regards.

11-08-2010, 12:28 PM	#4
jolepp Veteran Member Join Date: Oct 2010 Location: Finland Photos: Albums Posts: 3,196	I would keep on saving the original under a different name decreasing the JPEG quality until it is (slightly) under the limit: there is no exact rule for converting megapixels to megabytes as the compression ratio obtained depends on the contents of the picture as a whole as well as the JPEG quality used.

11-08-2010, 01:22 PM	#6
boriscleto Loyal Site Supporter Join Date: Dec 2009 Location: North Syracuse, NY Photos: Gallery Posts: 16,475	Originally posted by Adam It's important to note that some people make the mistake of thinking that a megabyte is 1,024,000 bytes, (1024x1000) rather than the 1,048,576 as Ananta properly pointed out (this number has become known as a mebibyte, 20^2 or 1024^2). Others have started using 1,000,000 bytes for a megabyte. Therefore, when uploading to websites, always assume the worst-case scenario and set the cutoff at 1,000,000 bytes Here on the forum, we go by the mebibyte designation in most areas. 1,048,576 is a megabyte only in reference to computer memory (RAM), although Microsoft continues to use it in the Windows file manager. The IEEE, SI, and IEC have decided that Mega means 1,000,000 with exceptions. Apple, as of 10.6 Snow Leopard have changed to the new definition.

11-08-2010, 02:29 PM	#7
Ananta Androscoggin Guest	The world just keeps dumbing-down . . .