Confused about Resolution Sony DSC-T7
2.2 MB is the size of the file on your hard disk. Being a .jpg, it is a compressed file. The file size does not reflect the size of the image stored inside the .jpg. Yes, the size sounds about right. It will increase or decrease depending on how much detail there is in the picture. If, for instance, your picture is made up of nothing but uninterrupted blue sky, the disk file will be quite small - as the .jpg does not need to store much information (the more repetitive information, the smaller the file). On the other hand, if your photo consists entirely of nothing but blades of grass, the disk file will be comparatively large.
When you see "DPI", that refers to print resolution. So, since you're not printing, but rather, viewing onscreen, Photoshop "assumes" a convenient "screen resolution", as though you printed on the screen (don't ask!). If you look at the other settings, you'll note that Photoshop also thinks your photo is 36" wide!!!
You adjust the DPI (or photoshop will) when you print. Till then, it doesn't mean much.
Let me give you an idea of your image's possible DPIs.
Assume you really want to print a 36" photo:
2592/36" = 72 DPI
If you make the picture 12" wide:
2592/12" = 216DPI
2592/10" = 259.2 DPI
2592/8" = 324 DPI
How do you get my photos above 200 DPI?
By printing the picture small enough, less than 12.96" on the wider side.
See calculations above.
The resolution at which you shot the image (2592X1944), will not cause blurriness.
As for the cause? There could be any number.
Was the subject moving?
Did you shake the camera while shooting?
Is your shutter speed too slow?
Should you have been using flash?
Is the camera autofocusing correctly?
Are you waiting for the autofocus to lock before pushing the shutter the rest of the way?
Hope this helps somewhat...