Scanning for web viewing. Warning: large file

I have an epson 3170 flatbed scanner and have been scanning some

medium format slides recently. When I scan at 600 dpi I get a file

appox. 1272X1272 2.65MB file. The resulting image looks great on my

monitor, although I must scroll to see everything. But the details

are great. The problem arises when I resize for web viewing either

at 511 width for here on PN or other sizes for blogs etc. When I

resize so much of the fine detail that made me awestruck in the

original scan seems lost on the smaller size pic. This pic is

nothing special, just one I'm using as an example because it shows a

lot a detail in the rocks. The film is provia 100, hassy with 80CF.

With my loupe the rainbow at the base of the waterfall is very

intense, but I guess a shortcoming of my un-pro scanner is a lack of

ability to pick it up. Please forgive the large file size. I

suggest if you use dial-up don't click link below.<div></div>

Here's another example of same scan resized to PN 511 size so you can see the difference.<div></div>

here's the same resized file but sharpened a tad more. Note the original large file was already sharpened but when I resized to 511 the sharpening seems to dissapear so I sharpened more but now it seems oversharpened possibly.<div></div>

Thanks in advance for any hints. I have a feeling that there is no real solution around this. I also have a dimage scan dual IV I just got for 35mm and wish I could master scanning my B&W negs.

[jautey]

Anthony,

Lets take your original file size of 1272X1272 now that equals a whooping 1,617,948

pixels. Resizing it to 511x511 results in 261,121 pixels. The resized file has 6 times

fewer pixels than the original. Any sharpness will be lost because there are 6 times fewer

pixels to give a value (color) too. The pixels don't get smaller; they stay a constant size.

The number of them gets smaller, thus less information can be included in the photo, like

fine lines and gradations. There is a terribly erudite explanation as to why the lighter

colored pixel (those that usually define sharpness in a digital photo) are lost, but suffice to

say it's a digital thing.

The type of film you used or the scanner or the camera makes no difference here. It's all

about the math.

 

Hope this helps.

Yes it does. Seems silly now.

[micheleberti]

You should sharpen the original file, the resize and then re-sharpen again using different settings in the USM