Archiving scans vs digital

I've been seriously looking in to getting a Canon EOS 10D DSLR so I

wouldn't have to scan all my film. It just takes so long. Currently,

I scan at 14-bit (Nikon Coolscan 4000 w/ SA-30), do my curves and

minor ajustments, save to 8-bit tiffs and then convert the whole roll

in to PNGs at once. When I get a full DVD's space I burn them on to a

recordable DVD and hope I don't lose it.<p>

 

 

How have people been archiving their digital negatives? I would

always shoot in RAW, but does one backup the RAW files, the 8-bit

adjusted files, both, or what? I consider the RAW files to be the

actual source, so I wouldn't want to delete them. How do you guys

usually handle this?

I back up an untouched TIFF and maybe some TIFFs that have major changes made that I'd like to keep. Certainly not PNG or proprietary RAW formats from cameras. I would suggest backing up the 16 bit scans if you're making them, but if not then just save the untouched 8bit tiff file. Burning to DVD is fine, but make 2 copies or something. I have all my images on internal hard drive as well as an external firewire hd. I am also slowly burning them to CD.

I store my images on CD.

 

What type of recordable DVD technology do you use? It was my understanding that there were a couple of competing choices and no standardization as yet.

I keep RAW files (after editing) on hard drive and a copy on very good CDRs (Mitsui Gold). I will also transfere 8 and 16 bit TIFFs to cheaper CDs to clean up disk space. I suppose if I had a "masterpiece" I would keep at least 2 copies of the finished TIFF.

 

6MP RAW files are 7-8MP and I consider these the digital negatives. Converted 16 bit TIFFs are about 36MB, so you could store about 20 per CD.

I back up all my unedited RAW images on CD-Rom. I back up master images as TIFFs separately.

RAW is nice for quality, but being proprietary and brand-specific it's a bit risky for archiving. I no longer see any point in archiving in TIFF, I use 8- or 16-bit PNGs, compression can be adjusted as one pleases.

 

If you're a bit computer savvy, having a second, older machine do batch-processing of a couple of gigabytes of images to PNG for archiving would be a good idea (this way, you can work as you like and need not worry about processing times). If you use photoshop, then psd is the fastest and easiest format to work with when you're preparing the image to be archived.

Oskar,<p>

16-bit PNGs? I was only aware that PNG files could be saved in 8-bit mode. When I try to save a 16-bit file in Photoshop 7 my only file options are PSD, RAW, or TIFF. Is there a different program that can batch convert my TIFFs to PNG, and realistically, if my intention is printing and my adjustments have been made, then do I really need the extra 8-bits of color data considering the substantially reduced color gamut of a printer?<p>

Or maybe the 16-bit PNG was a typo?

<I>What type of recordable DVD technology do you use? It was my understanding that there were a couple of competing choices and no standardization as yet.</I><P>

 

There are, in fact 3 competing standards, or even four, depending on how you count them. There are also two <B>NEW</B> ones coming out!!<P>

 

 

Assuming you really mean "ARCHIVING", and not just short-term backups, using DVD is an extremely risky gamnble right now. There are just too many competing standards and mutual incompatibilities. Unlike CD-R's, DVD for data storage (as opposed to DVD players for rented movies) in any one standard has never caught on widely enough among the general public to provide a strong incentive for PC makers to provide lots of backward compatibility for generations of PC's to come. Hence, there is no reason to think that in 10 or 15 years you'll be able to easily recover your files, even if the data on them is perfectly intact.<P>

 

On the other hand CD-R's don't hold much. A high-res (4000 PPI) scan of a 35mm frame is 24 megapixels. At 16 bits/channel that's 6 bytes/pixel, or 144 megabytes per file. So that's what - 5 files per CD? How many pits/pixel is the 10D?<P>

 

Compression might help but keep in mind that all lossless compression methods tend to have limited performance that's sensitive to the degree of local similarity. Since film images (grain) and digicam images (noise) tend to have very little local similarity they don't compress well. If you get a 2:1 compression with a typical, detailed, real-world photo you're doing well.

I wrote: <I>How many pits/pixel is the 10D?</I><P>

 

That should say "bits/pixel". I didn't mean to imply the 10D is the pits. On the other hand it is true that CD's store bits as pits.

Peter,<p>

Your worries about the usability of DVDs are flawed, because you're worrying about the recording standards. The reading standards are basically the same. I currently write DVD-R, but all my DVD drives in the house can read DVD+-R/RW. All the formats are readable (short of the blue laser coming out, which will <b>still</b> be able to read all the older formats.<p>

To invest in a recording technology and say that I want to use DVD-R in 10 years is pointless, but in 10 years I will still be able to read them. Heck, if I have to change mediums every five or ten years its no big deal since the storage capacity will increase exponentially. Besides, I can still get 5.25" floppy drives for $25.<p>

Nick

<i>16-bit PNGs? I was only aware that PNG files could be saved in 8-bit mode.</i>

 

<p>PNGs can be either palette, 8-bit/channel or 16-bit/channel. PS7 can read 16-bit PNGs but not save, but there's a free plug-in available for both Macs and PCs called <a href="http://www.fnordware.com/superpng/">SuperPNG</a>, which allows you to save 16-bit PNGs (although without profiles when I last tested). I'm looking into saving PSD/uncompressed TIFF and using <a href="ImageMagick">ImageMagick</a> to convert to PNG, as working with PNGs in PS is a bit slow (ImageMagick has a bit of a learning curve, but in return offers many practical adjustments). The profiles can be added removed with ImageMagick or pngcrush or similar if that's what you need.

 

<p>It might well be that the "final" versions of your images need not be 16-bit images, but there are some kinks in PS7's PNG-engine. In general, if you're saving a DVD at a time, I suggest using PSD for editing and then using a batch-conversion on the images to prepare them for the DVD (during which you can go out and enjoy the springtime rather than sit in front of the computer).