Question about scanning negatives

I'm scanning some of my color negs using a Nikon Coolscan IV (2900
dpi). I'm scanning at 48 bits in the hope of capturing maximum tone
gradations. It seems to work great... only problem is the TIF files
are weighing in at around 65 megs each. There will be several hundred
scans, maybe even a couple of thousand (depending on how long I can
tough it out...) and that's a lot of hard drive space.

So my question is, is there a recommended way to reduce the file size
without losing data that matters?

The scans are roughly 11 megapixels, about the same as with digital
cameras, yet are way bigger than digital camera output. There must be
a lot of unnecessary data in there...

Archibald

"Archibald" wrote in message
...
I'm scanning some of my color negs using a Nikon Coolscan IV (2900
dpi). I'm scanning at 48 bits in the hope of capturing maximum tone
gradations. It seems to work great... only problem is the TIF files
are weighing in at around 65 megs each. There will be several hundred
scans, maybe even a couple of thousand (depending on how long I can
tough it out...) and that's a lot of hard drive space.

So my question is, is there a recommended way to reduce the file size
without losing data that matters?

The scans are roughly 11 megapixels, about the same as with digital
cameras, yet are way bigger than digital camera output. There must be
a lot of unnecessary data in there...

Archibald


According to my sums 1000 pics at 65 Mb each is 65 Gig, double that is 130
Gig.

To store that lot, all you would need is a smallish external Hdd, and they
are very reasonably priced at the moment.

If the files really are too big for you, then once you have adjusted the
colour and density to your own taste, convert them back to 8 bit per
channel.

Roy G

Archibald wrote:
I'm scanning some of my color negs using a Nikon Coolscan IV (2900
dpi). I'm scanning at 48 bits in the hope of capturing maximum tone
gradations. It seems to work great... only problem is the TIF files
are weighing in at around 65 megs each. There will be several hundred
scans, maybe even a couple of thousand (depending on how long I can
tough it out...) and that's a lot of hard drive space.

So my question is, is there a recommended way to reduce the file size
without losing data that matters?

The scans are roughly 11 megapixels, about the same as with digital
cameras, yet are way bigger than digital camera output. There must be
a lot of unnecessary data in there...

Archibald

This may not be the way most people would see this but I am working on
scanning a lot of old family pictures. The question I asked when I
started this project was "Is the innate resolution of the pictures worth
maintaining the best high resolution image files for the pictures. (Is
it necessary to maintain a 10 mega pixel images of pictures that are of
1.3 mega pixel quality.)

I decide to keep the files in sizes more inline with the original images
than in files of current capabilities

I scan the pictures to high resolution JPG files that preserve the
resolution of the original pictures and provide economy in storage.
Even after manipulation and resaving the quality of the original 50 to
100 year old photo is maintained.

Keith wrote on Tue, 23 Sep 2008 16:59:10 -0400:

Archibald wrote:
I'm scanning some of my color negs using a Nikon Coolscan IV
(2900 dpi). I'm scanning at 48 bits in the hope of capturing
maximum tone gradations. It seems to work great... only
problem is the TIF files are weighing in at around 65 megs
each. There will be several hundred scans, maybe even a
couple of thousand (depending on how long I can tough it
out...) and that's a lot of hard drive space.

So my question is, is there a recommended way to reduce the
file size without losing data that matters?

The scans are roughly 11 megapixels, about the same as with
digital cameras, yet are way bigger than digital camera
output. There must be a lot of unnecessary data in there...

Archibald

This may not be the way most people would see this but I am
working on scanning a lot of old family pictures. The
question I asked when I started this project was "Is the
innate resolution of the pictures worth maintaining the best
high resolution image files for the pictures. (Is it
necessary to maintain a 10 mega pixel images of pictures that
are of 1.3 mega pixel quality.)

I decide to keep the files in sizes more inline with the
original images than in files of current capabilities

Have you looked at Wayne Fulton's Scanning Tips?
I found it most enlightening.
http://www.scantips.com/basics09.html


--

James Silverton
Potomac, Maryland

Email, with obvious alterations: not.jim.silverton.at.verizon.not

Archibald wrote:
I'm scanning some of my color negs using a Nikon Coolscan IV (2900
dpi). I'm scanning at 48 bits in the hope of capturing maximum tone
gradations. It seems to work great... only problem is the TIF files
are weighing in at around 65 megs each. There will be several hundred
scans, maybe even a couple of thousand (depending on how long I can
tough it out...) and that's a lot of hard drive space.

So my question is, is there a recommended way to reduce the file size
without losing data that matters?

The Dmax of the scanner is 3.6 (manufacturer claim) indicating:

10^3.6 = 3981 levels per color. That fits into 12 bits (4096), so the
48 bit (16 bits per color) is at least 4 bits/color of waste ... or 12
bits total per pixel that is deep in the noise.

In reality you can throw away at least 1 bit to noise, so it's really 11
bits/color or 33 per pixel. 33/8 * 11.262 Mpix = 46 Mpixels for the
useful information in simple compression. However, the scanner does not
store that way. (Check you Nikon s/w; maybe there is a compressed mode).

However, in photoshop, you can save the TIF compressed. Try that. You
should get about 10% - 20% depending on image content.

Get an external hard drive (1 TB) for archiving...

Don't weep. My Nikon 9000 scans of MF film come to about 460 MB...

Cheers,
Alan.

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Archibald added these comments in the current discussion du jour
....

I'm scanning some of my color negs using a Nikon Coolscan IV
(2900 dpi). I'm scanning at 48 bits in the hope of capturing
maximum tone gradations. It seems to work great... only
problem is the TIF files are weighing in at around 65 megs
each. There will be several hundred scans, maybe even a couple
of thousand (depending on how long I can tough it out...) and
that's a lot of hard drive space.

So my question is, is there a recommended way to reduce the
file size without losing data that matters?

The scans are roughly 11 megapixels, about the same as with
digital cameras, yet are way bigger than digital camera
output. There must be a lot of unnecessary data in there...

Just a question and NOT an insult, are the negs capable of
extracting this much information at 48bits, i.e., was a good camera
and good technique used? Or, are you doing this because there's a
known dynamic range problem you're trying to overcome? The reason I
ask is that if parts of the neg are either clear or black or both
then there's no point in going to 48 bits as there ain't in info at
the extremes of the range to extract.

As to your last paragraph, most modern digitals do not support
TIFF, only JPEG and RAW (or both). Have you at all consider a very
conservatie JPEG compression, say 3-5 on the standard 1-5 scale?
Maybe you could go even higher if you do some tests to match sizes
and look for the presence of any visible damage at those
resolutions, much the same as you would with a quality DSLR using
whatever the finest quality is (and you're not using RAW, which I
do not).

Finally, it seems to me that the main issue isn't HDD space but
execution time to manipulate images that large and requirements for
multiple undos being written to disk.

--
HP, aka Jerry

"Don't say 'can't' when you really mean 'won't'"

Keith nuttle added these comments in the current discussion du
jour ...

Archibald wrote:
I'm scanning some of my color negs using a Nikon Coolscan IV
(2900 dpi). I'm scanning at 48 bits in the hope of capturing
maximum tone gradations. It seems to work great... only
problem is the TIF files are weighing in at around 65 megs
each. There will be several hundred scans, maybe even a
couple of thousand (depending on how long I can tough it
out...) and that's a lot of hard drive space.

So my question is, is there a recommended way to reduce the
file size without losing data that matters?

The scans are roughly 11 megapixels, about the same as with
digital cameras, yet are way bigger than digital camera
output. There must be a lot of unnecessary data in there...

Archibald

This may not be the way most people would see this but I am
working on scanning a lot of old family pictures. The
question I asked when I started this project was "Is the
innate resolution of the pictures worth maintaining the best
high resolution image files for the pictures. (Is it
necessary to maintain a 10 mega pixel images of pictures that
are of 1.3 mega pixel quality.)

I decide to keep the files in sizes more inline with the
original images than in files of current capabilities

I scan the pictures to high resolution JPG files that preserve
the resolution of the original pictures and provide economy in
storage. Even after manipulation and resaving the quality of
the original 50 to 100 year old photo is maintained.

Your logic is compelling and is what I use in scanning family
pictures whether they are B & W snaps from the 1950s, formal
photographs from that era or even earlier, or even more modern
snaps, slides, or negs from all but the best cameras. I've got
literally thousands that I MAY get around to doing something with
someday but all of them except a small percentage are pretty
small snapshots taken with the "P & S" cameras of the day,
usually Kodak or Ansco single lense range finder of twin lens
reflex jobs, but none with focusing ability nor exposure control.
So, quality by the time my family went from taking the pics to
developing the negs to getting them printed was crude in them
days, to say the least.


--
HP, aka Jerry

"Don't say 'can't' when you really mean 'won't'"

Scott W added these comments in the current discussion du jour
....

On Sep 23, 6:25*am, Archibald wrote:
I'm scanning some of my color negs using a Nikon Coolscan IV
(2900 dpi). I'm scanning at 48 bits in the hope of capturing
maximum tone gradations. It seems to work great... only
problem is the TIF files are weighing in at around 65 megs
each. There will be several hundred scans, maybe even a
couple of thousand (depending on how long I can tough it
out...) and that's a lot of hard drive space.

So my question is, is there a recommended way to reduce the
file size without losing data that matters?

The scans are roughly 11 megapixels, about the same as with
digital cameras, yet are way bigger than digital camera
output. There must be a lot of unnecessary data in there...
Do a test, save some of your better scans as jpegs at the
highest quality, lowest compression, and see if you can see
any real differences between the jpeg and tiff images.

I agree.

--
HP, aka Jerry

"Don't say 'can't' when you really mean 'won't'"

On Tue, 23 Sep 2008 17:16:48 -0400, Alan Browne
wrote:

Archibald wrote:
I'm scanning some of my color negs using a Nikon Coolscan IV (2900
dpi). I'm scanning at 48 bits in the hope of capturing maximum tone
gradations. It seems to work great... only problem is the TIF files
are weighing in at around 65 megs each. There will be several hundred
scans, maybe even a couple of thousand (depending on how long I can
tough it out...) and that's a lot of hard drive space.

So my question is, is there a recommended way to reduce the file size
without losing data that matters?

The Dmax of the scanner is 3.6 (manufacturer claim) indicating:

10^3.6 = 3981 levels per color. That fits into 12 bits (4096), so the
48 bit (16 bits per color) is at least 4 bits/color of waste ... or 12
bits total per pixel that is deep in the noise.

In reality you can throw away at least 1 bit to noise, so it's really 11
bits/color or 33 per pixel. 33/8 * 11.262 Mpix = 46 Mpixels for the
useful information in simple compression. However, the scanner does not
store that way. (Check you Nikon s/w; maybe there is a compressed mode).

However, in photoshop, you can save the TIF compressed. Try that. You
should get about 10% - 20% depending on image content.

If I resave using LZW compression, the file size INCREASES by about
20%.

Archibald

Archibald wrote:
On Tue, 23 Sep 2008 17:16:48 -0400, Alan Browne
wrote:

Archibald wrote:
I'm scanning some of my color negs using a Nikon Coolscan IV (2900
dpi). I'm scanning at 48 bits in the hope of capturing maximum tone
gradations. It seems to work great... only problem is the TIF files
are weighing in at around 65 megs each. There will be several hundred
scans, maybe even a couple of thousand (depending on how long I can
tough it out...) and that's a lot of hard drive space.

So my question is, is there a recommended way to reduce the file size
without losing data that matters?
The Dmax of the scanner is 3.6 (manufacturer claim) indicating:

10^3.6 = 3981 levels per color. That fits into 12 bits (4096), so the
48 bit (16 bits per color) is at least 4 bits/color of waste ... or 12
bits total per pixel that is deep in the noise.

In reality you can throw away at least 1 bit to noise, so it's really 11
bits/color or 33 per pixel. 33/8 * 11.262 Mpix = 46 Mpixels for the
useful information in simple compression. However, the scanner does not
store that way. (Check you Nikon s/w; maybe there is a compressed mode).

However, in photoshop, you can save the TIF compressed. Try that. You
should get about 10% - 20% depending on image content.

If I resave using LZW compression, the file size INCREASES by about
20%.

Interesting.

Try "ZIP" compression (from photoshop) on your TIF - I get 10%
compression on a large TIFF.

What it really comes down to is getting an algorithm that recognizes
what level of bits are useless and can be truncated.

Anyway, I don't compress files. Memory is much cheaper than my time.
Get an external drive (1TB or so) and you'll be quite happy.

--
-- r.p.e.35mm user resource: http://www.aliasimages.com/rpe35mmur.htm
-- r.p.d.slr-systems: http://www.aliasimages.com/rpdslrsysur.htm
-- [SI] gallery & rulz: http://www.pbase.com/shootin
-- e-meil: Remove FreeLunch.
-- usenet posts from gmail.com and googlemail.com are filtered out.