TG-1 file size

That seems to be the norm for a jpeg image - unlike the raw files that have all of your data, jpeg's compress/process the image already, before we get a chance to do our own tweaking.  Here's a basic explanation I saw:

"In comparison a JPEG is…

• a standard format readable by any image program on the market or available open source.
• exactly 8-bits per color (12-bits per location).
• compressed (by looking for redundancy in the data like a ZIP file or stripping out what human can’t perceive like a MP3).
• fairly small in file size (an 8 megapixel camera will produce JPEG between 1 and 3 MB’s in size).
• lower in dynamic range.
• higher in contrast.
• sharper.
• immediately suitable for printing, sharing, or posting on the Web.
• not in need of correction most of the time (75% in my experience).
• able to be manipulated, though not without losing data each time an edit is made – even if it’s just to rotate the image (the opposite of lossless).
• processed by your camera."

-- from this site: Digital Photography School

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Camera gear in profile.
Ken G.
http://www.pbase.com/kgilbertsen/