Thomas T. Veldhouse wrote:
> "Roger N. Clark (change username to rnclark)" <username.DeleteThis@qwest.net> wrote:
>
>>While 2400 dpi may be fine for higher ISO films done hand held, it is very
>>inadequate for tripod mounted fine grained film images. Note too
>>that scanner ratings are higher than they should be. By this I mean
>>that consumer scanners, in the many I have tested, rate about
>>2/3 the ppi compared to drum scans. Thus a 2400 ppi scanner
>>is really more like a 1600 ppi drum scan. If you want real 2400 ppi,
>>you need a 3600 ppi scanner. The highest resolution films,
>>like kodachrome and velvia have information above 4000 ppi
>>(drum scans), so if you have images that are critically sharp,
>>you need a 5000 ppi scanner, and a bare minimum of a 4000 ppi
>>quality scanner. I've also found benefit in scanning at 12-bits
>>per pixel when I want to maintain detail from deep shadows to bright
>>highlights.
>>
>
>
> Would I be correct to indicate that this type of scan would more benefit
> work in progress and be less of a benefit for archival purposes? Or do
> you honestly archive 130+ MB files?
Yes I do archive such files. In fact, my 4x5 scans are 1 GByte each.
The work of scanning and fixing defects is huge compared to the cost and
effort of saving the file. I save to firewire drives which I keep offline.
I actually use two drives which I alternate backups (soon I'll go to three).
Drives are cheap compared to the effort I've done to get the images
in final form.
>
> My general rule for doing work right from film is to scan at max 16-bit
> resolution and work in AdobeRGB until I get to the images final form, at
> which time I target the image (so .. 8 x 10 @ 400 dpi converted to a
> printer colorspace ... usually 8-bit) for final output. A reasonable
> compromise for archival purposes is where I am having trouble. If there
> was a useful way to shrink the large image in a similar manner to RAW
> from a camera put into NEF format, that would be great (I assume there
> must be some selective loss somewhere).
If you intend to print once and never again, I might agree with
your strategy. But printing technology has been constantly evolving,
so making your final archive file tied to a specific printer
color space is like freezing the image in time, and may never
be able to print again.
I archive my original scans to DVD, then the processed final scan
is archived to hard drives and DVD, one set of each is stored
off site. I also create printer profiled images for specific
printers. I typically have an 8x10 for my inkjet, and then
lightjet Fuji Crystal Archive files at full resolution. Then
for various print sizes (e.g. 11x14, 16x20, 24x30, 30x40...),
when I create the file and have a print made, I archive the
interpolated image profiled for the printer. I archive
each of these as my time to recreate them is more
than it takes to archive them.
Example:
image1.tif (final image,
usually 16-bits/channel)
image1-lightjetprofile.tif (same resolution as final image)
image1-LJ24x30.tif (interpolated, sharpened reduction
of image1-lightjetprofile.tif)
image1-LJ11x14.tif (interpolated, sharpened reduction
of image1-lightjetprofile.tif)
image1-inkjet8x10.tif (interpolated, sharpened reduction
of image1.tif with inkjet profile)
All the above get archived. If a new printer comes along, I can start
from the original.
For snapshots, I do not do this. I save jpegs only (highest quality).
For my 4x5s, archiving one image requires 3 to 5 gigabytes.
Roger
>> Stay informed about: What workflow for film scanning and archiving?