Epson 3200 File Size with Vuescan vs Epson

  • Thread starter Thread starter David R
  • Start date Start date
D

David R

I scanned one medium format B/W negative with both the Epson 1.25a and
Vuescan 78 software. Can someone explain why such a file size
difference?

334,584KB - Epson 1.25a (w3.627" x h4.612", resolution 3200)
96,814KB - Vuescan 78 (w3.663" x h4.517", resolution 3200)

I saved them to an uncompressed TIFF file. My scan settings were as
follows

16 Bit Gray for both software
Scan Resolution at 3200 for both software
Filters on Vuescan were set at Restore Color On, Restore Fading On,
Grain Reduction Off, and Sharpen On.
Filters on Epson 1.25a were set at Unsharpen Mask Filter Level High.
Target Size Original for both software.
Crop size was as close to the same for each.

Both scans look excellent. The Epson scan took half the time as the
Vuescan time.
 
I scanned one medium format B/W negative with both the Epson 1.25a and
Vuescan 78 software. Can someone explain why such a file size
difference?

334,584KB - Epson 1.25a (w3.627" x h4.612", resolution 3200)
96,814KB - Vuescan 78 (w3.663" x h4.517", resolution 3200)

I saved them to an uncompressed TIFF file. My scan settings were as
follows

16 Bit Gray for both software
Click to expand...

3.6 x 4.6 inches @ 3200ppi = apprx. 161MB in 8bit grayscale, double that
for 16 bit.

The VueScan one is too low for even 8 bit, so you must have either:
- set output size to something smaller for save
- used LZW even though you didn't mean to.

Check pixel dimensions of both. They should be relatively close, but I
bet they're not.

Mac
 
Vuescan outputting tiff files defaults to some compression if it's left on
auto. You'll have to change it to get to the tiff settings.
 
David said:
Vuescan outputting tiff files defaults to some compression if it's left on
auto. You'll have to change it to get to the tiff settings.
Click to expand...

Tiff lossless compression should not make such a large difference in
file size unless the image is highly unusual in distribution of tones.

Most likely the Vuescan scan was actually made at some other setting.
 
Mac McDougald said:
I should have concluded, "OR LZW got applied".

M
Click to expand...

The Epson Pixel size looks much larger. Here are the reading as viewed by PS.
Epson Pixel Dimensions: 326.7M (w11606 x h14758)
Vuescan Pixel Dimensions: 161.5M (w11720 x h14453)
 
David said:
The Epson Pixel size looks much larger. Here are the reading as viewed by PS.
Epson Pixel Dimensions: 326.7M (w11606 x h14758)
Vuescan Pixel Dimensions: 161.5M (w11720 x h14453)
Click to expand...

(11,606 * 14,758) * (16bits/8bitsPerPixel) = 342.56 MB
(11,702 * 14,453) * (8 bits/8bitsPerPixel) = 169.13 MB

In Viewscan, is the setting for Output|Tiff file type set to
"16-bit gray" or "8-bit gray"? It should be the former.
 
The Epson Pixel size looks much larger. Here are the reading as viewed by PS.
Epson Pixel Dimensions: 326.7M (w11606 x h14758)
Click to expand...

That's right for 16 bit.
Vuescan Pixel Dimensions: 161.5M (w11720 x h14453)
Click to expand...

That's right for 8 bit.

So, you saved the VueScan one at 8 bit, and since you say the saved VS
image is only 96MB on disk, you must have LZW compression on it also.
Simple as that.

Mac
 
Hello, David R
you wrote...
The Epson Pixel size looks much larger. Here are the reading as viewed by PS.
Epson Pixel Dimensions: 326.7M (w11606 x h14758)
Vuescan Pixel Dimensions: 161.5M (w11720 x h14453)
Click to expand...

To know exactly what happend you can go to libtiff.org and get the
libtiff software package (for windows follow the windows binaries
link). The tiff tools are part of the package, tiffinfo gives you the
appropriate infos.
 
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