Nikon NX reduces file size when sharpening?

[sandiegojoey]

I just noticed that each time I sharpen a jpeg image using the "unsharp mask" tool in Capture NX, it reduces the file

size by almost 50%. I have to admit that I'm not sure I'm doing this right to begin with. I'm shooting my daughters

Field Hockey games with a Nikon D3 and 70-200mm f/2.8VR in A priority and Auto ISO (JPEG mode). The images

are coming out great, with one exception, I'd like them to look a bit sharper.

 

When I open them using Capture NX they look a littel soft (even though I crank up the sharpening in the camera).

They seem to look better (at least on my monitor) when I use the Unsharp Mask tool. The tool has three sliders,

Intensity, Radius, and Threshold. Each time I open the tool, the Radius slider is automatically set at 5% while the

other two are at 0%. When I slide the Intensity bar to the right at about 60%, the image looks much nicer on my

monitor and I assume with look the same when I print, so I leave the other two sliders alone and save. However, my

JPEG image will go from 5.8MB down to 3.2MB just from that function alone. If I want to crop on top of that I end up

with 1mb images!

 

Where is that information going? Am I actually degrading the quality of my images when I do that? I upload them to

Costco for parents to print and I'm concerned that the reduced file size will not allow quality 8x10 prints or even

larger.

 

What, if anything am I doing wrong?

 

thanks.....Joey

[twmeyer]

Are you working from a compressed NEF (16bit) and saving as a JPG (8bit) with higher compression? Are you

measuring the file size when it is closed, or when you open the file in editing software like Photoshop or

Elements?<p>Open the file in your editing software and check its resolution (ppi) and it's actual dimensions. Are

they same in both the pre and post edited files?<p>An 8bit jpg, when open will be half the size of a 16bit NEF or

tif file, yet have the same resolution and dimensions... t