Question about digital archive file sizes

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I recently bought a Canon FS2710 that I am happy with by the way. I am wondering: I can transfer 16 bit files at 2710 dpi to create a file size just under 60MB. Do I need that much information for an archive or can I make the file size smaller without loosing too much information? Also can someone tell me what is BATCH Scanning? Thanks Robb Russell

-- Robb Russell (rnkrussell@hotmail.com), May 11, 2000

Answers

i sincerely doubt that the scanner is able to scan at 16bit.. they usually fall around the 8-12bit category so you might be able to save some space there... and it all depends on what you plan to do with the files... do you require them to be that large of a size? i usually want good quality scans at 8x10 so the final picture will be printed at 300 dpi to give me a resolution of around 2400x3000... and with that resolution it will give me at least a decent quality at 11x14

batch scanning is what it means.... scanning them in a batch... some scanners have adapters to scan a stack of slides... some scanners accepts a strip of film... some scanners accepts aps film and batch scanning would scan those film and crop/save them in batches...

-- Keat Lim (keatlim@my-deja.com), May 11, 2000.


I wouldn't bother saving a 16-bit file. We had a discussion on the merits of working in a 16-bit color space on photo.net a few weeks ago. Several of use (those with experience on drum scanners for what that's worth) argued that manipulating a 16-bit file was a waste of disk space. Others argued that the extra bits give PhotoShop more information to calculate when applying filters and adjusting curves, thus decreasing the noise level. I'm still firmly in the eight-bit camp.

The key is getting a proper scan before working on the file. If you get the best scan possible, you're working on clean data. Using something like the FS2710 (I'm not picking on your scanner here, just making a point) and working in a 16-bit space means you're just working with more noise, especially in the shadows. Even with low-end scanner such as the FS2710 and Nikon LS2000, getting a proper scan and working in eight-bit mode gives me identical results as working in 16-bit mode. So no, you're not losing information by working in eight-bit mode.

When I archive my files I always save a raw scan as an eight-bit LZW compressed TIFF. After adjusting the color balance and cleaning off any dust and other defects I then save the file with the name "xxxx_master.psd" and archive that. Then I'm ready to work on the specific print sizes where I'll apply the unsharp mask as the last step before printing. I archive those files too. As you might imagine, I'm getting quite a collection of CDs. A 40GB hard drive comes in handy too.

-- Darron Spohn (dspohn@photobitstream.com), May 11, 2000.


Keat, the scanner doesn't scan to 16 bit depth, only 12 bits, but there is no file format between 8 bits/pixel and 16 bits/pixel. A waste of disk space, I know, but that's the way it is. The only file format I know of that supports 16 bit depth is TIFF.

The quality difference from manipulating 16 bit files versus 8 bit files in Photoshop is very noticeable. Anyone who says they can't see any difference should get their monitor adjusted, or their eyes tested.

-- Pete Andrews (p.l.andrews@bham.ac.uk), May 12, 2000.


Anyone who says they can't see any difference should get their monitor adjusted, or their eyes tested.

Anyone who can see the difference needs to start with better scans. My monitor is calibrated properly. I'm just spoiled by working on 100- 300MB scan from a Tango drum scanner. I stand by my statement that with lesser scanners all you're doing is manipulating noise.

Get a proper drum scan done and you'll see what I mean.

-- Darron Spohn (dspohn@photobitstream.com), May 14, 2000.


Darron, why are you so keen for the users of desktop scanners to throw away the last 4 bits of their data? And why do you keep rubbishing desktop scanners, when you obviously have no intention of using one? I can assure you that I don't waste my time making noise more visible in my scans. The extra 4 bits of data represent a 16:1 increase in the dynamic range of the image, and this isn't to be scoffed at.

Back to the original question: There is an interesting article on (Darron's beloved) West-coast Imaging website about the philosophy of "Scan once, purpose many"

That's HER E

It makes a very good case for storing images in the highest quality format that you can.

-- Pete Andrews (p.l.andrews@bham.ac.uk), May 15, 2000.



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