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Archive for April 16th, 2005
4/16/05
12:22 am
Sizes

More on the Film Scanner.

Without doing much, scanning a 35mm slide at 16 bit resolution without changing anything else gets you a 120M TIFF file. Yes, 120M, as in 122,927,684 bytes. Seems like a lot for a single picture, doesn’t it?

So, I started to look at the sizes for other cameras and what to expect. First off, some comparisons between the scanner, a Canon S500 5MP camera, and an older Kodak 2M camera.

Camera Pixel dimensions (landscape) DPI Page dimensions (inches) File size (K)
Kodak DC280 2 MegaPixel 1760×1168 192dpi 9.167×6.083 453K
Canon S500 5 MegaPixel 1944×2592 180dpi 10.8×14.4 2,282K
Nikon Coolscan 5000ED 35mm scan TIFF 5587×3675 4000dpi 1.397×0.919 122,927K
Nikon Coolscan 5000ED 35mm scan JPG 5587×3675 4000dpi 1.397×0.919 7,894K

The key takeaway here is how impressive the JPG compression is… from 122M to under 8M — very nice! So, I’m busy scanning things to save as JPEG now, and I’ll be down-converting the few rolls of TIFFs I did into JPEGs…. should compress nicely.

The scanner dimensions are also weird…. that matters is the pixel density. The DPI and size of the page are just arbitrary… say I divide DPI by 4 to 1,000… then I can double the length and width of the image. Whatever.