| Author |
Message |
Roger N. Clark (change us
Guest
|
 Posted:
Mon Oct 31, 2005 5:40 am Post subject:
Digitizing negatives with a digital camera |
|
|
Hi,
I have a bunch of old 2 1/4 x 2 1/4 negatives from family
members. The negatives, many color, are in good shape,
buy I have thousands to digitize. I could do the job fast with
my Canon 1D Mark II and 180 mm f/3.5 L macro lens. This system
gives more than enough resolution (it resolves film grain clumps),
and with raw output has the intensity precision (12 bits).
The problem I have is how do I convert the negative to a
positive (I have Photoshop CS2)? I can batch convert the raw
files using a linear or other custom transfer function
(using other programs). But when I do a simple "invert"
in photoshop I get a very blue image.
When I scan the negative on my Epson 4990 scanner (1200 ppi
is adequate to resolve all the detail in these hand-held pictures),
the colors come out great. I estimate I could do the digitizing
about 5 or more times faster with the camera compared to the
flatbed scanner.
Any ideas on how to get the colors right?
Thanks
Roger
|
|
| Back to top |
|
 |
bmoag
Guest
|
| Posted:
Mon Oct 31, 2005 5:40 am Post subject:
Re: Digitizing negatives with a digital camera |
|
|
Le masque d'orange.
If you do your research you will find several formulas for dialing in color
correction to get rid of the orange masking of color negative film.
If you are time obesessed then calculate whether having the flatbed scanner
automatically remove the orange mask or manually removing it in PS is more
efficient.
Personally I cannot believe you would think doing this with your digital
camera is in any way more efficient or will yield better quality images than
using a decent flatbed scanner and software for 2.25 film materials.
How do you rapidly frame, focus and photograph with even illumination across
the field in any time that is more efficient than using a decent flat bed
scanner?
Sacre bleu!
If you do not photograph the film grain clumps than what exactly are you
photographing as grain clumps are what make up the film image. If you do not
resolve the grain you are producing digital mush copies of your film
originals.
I would hypothesize that in the time to post this, read the responses from
skeptics or true believers, you could have finished the entire project with
your flat bed scanner. |
|
| Back to top |
|
|
Ryan
Guest
|
| Posted:
Mon Oct 31, 2005 5:40 am Post subject:
Re: Digitizing negatives with a digital camera |
|
|
Roger N. Clark wrote:
| Quote: | I have a bunch of old 2 1/4 x 2 1/4 negatives from family
members. The negatives, many color, are in good shape,
buy I have thousands to digitize.
|
bmoag wrote:
| Quote: | I would hypothesize that in the time to post this, read the responses from
skeptics or true believers, you could have finished the entire project with
your flat bed scanner.
|
Wow, if he can finish several THOUSAND scans in the same time it takes
him to read through a couple of posts in a single topic, then I know a
few places that would give him a freaking job. |
|
| Back to top |
|
|
Roger N. Clark (change us
Guest
|
| Posted:
Tue Nov 01, 2005 5:40 am Post subject:
Re: Digitizing negatives with a digital camera |
|
|
David J. Littleboy wrote:
| Quote: | "Bart van der Wolf" <bvdwolf@no.spam> wrote:
In order to get the colors right, and reduce posterization/noise, you'll
need to use blue filtered light. The trick is to start with a neutral
white rendition of the film base (mask). You either change the color of
the lightsource, or filter the light that enters the camera with a filter
Sheesh. You're flipping brilliant. Really. I've been ranting for ages how
after-the-fact white balancing is bogus and digital requires color
correction filters just as much as film, and completely missed that that's
exactly what's required here.
Ain't it amazing how "brilliance" consists of seeing the obvious???
David J. Littleboy
Tokyo, Japan
|
Bart,
Great info! I'll try it. I do have a number of blue
filters around.
David, I agree.
Roger |
|
| Back to top |
|
|
Bart van der Wolf
Guest
|
| Posted:
Tue Nov 01, 2005 5:40 am Post subject:
Re: Digitizing negatives with a digital camera |
|
|
"Roger N. Clark (change username to rnclark)" <username@qwest.net>
wrote in message news:43658C4E.2040208@qwest.net...
SNIP
| Quote: | The problem I have is how do I convert the negative to a
positive (I have Photoshop CS2)? I can batch convert the raw
files using a linear or other custom transfer function
(using other programs). But when I do a simple "invert"
in photoshop I get a very blue image.
|
In order to get the colors right, and reduce posterization/noise,
you'll need to use blue filtered light. The trick is to start with a
neutral white rendition of the film base (mask). You either change the
color of the lightsource, or filter the light that enters the camera
with a filter
Equal Digital Numbers for R/G/B of the film base will optimize S/N if
they approach saturation, and produce color accurate blacks after
inversion. Subsequent white balancing will get the highlights right
and all intermediate luminosities should more or less follow. A final
saturation tweak should allow you to get close to reasonable
rendition, except for potential dye fade. Restoring faded dyes is a
different subject altogether, because their fade rate is different per
color.
Bart |
|
| Back to top |
|
|
David J. Littleboy
Guest
|
| Posted:
Tue Nov 01, 2005 5:41 am Post subject:
Re: Digitizing negatives with a digital camera |
|
|
"Bart van der Wolf" <bvdwolf@no.spam> wrote:
| Quote: |
In order to get the colors right, and reduce posterization/noise, you'll
need to use blue filtered light. The trick is to start with a neutral
white rendition of the film base (mask). You either change the color of
the lightsource, or filter the light that enters the camera with a filter
|
Sheesh. You're flipping brilliant. Really. I've been ranting for ages how
after-the-fact white balancing is bogus and digital requires color
correction filters just as much as film, and completely missed that that's
exactly what's required here.
Ain't it amazing how "brilliance" consists of seeing the obvious???
David J. Littleboy
Tokyo, Japan |
|
| Back to top |
|
|
Bart van der Wolf
Guest
|
| Posted:
Wed Nov 02, 2005 5:39 am Post subject:
Re: Digitizing negatives with a digital camera |
|
|
"David J. Littleboy" <davidjl@gol.com> wrote in message
news:dk6dnr$742$1@nnrp.gol.com...
SNIP
| Quote: | Ain't it amazing how "brilliance" consists of seeing the obvious???
|
It probably stems from our prior 'education' in photographic film /
wet chemistry. Even before digital photography became popular,
Garbage-In-Garbage-Out (GIGO) ruled.
Just because we can manipulate the result with more ease, it still
pays to get it right from the start.
Bart |
|
| Back to top |
|
|
Bart van der Wolf
Guest
|
| Posted:
Wed Nov 02, 2005 5:40 am Post subject:
Re: Digitizing negatives with a digital camera |
|
|
"Roger N. Clark (change username to rnclark)" <username@qwest.net>
wrote in message news:4366C7F0.9020107@qwest.net...
SNIP
| Quote: | Bart,
Great info! I'll try it. I do have a number of blue
filters around.
|
Those would at least improve the green and blue S/N. Alternatively,
you could try 3 exposures (rough first approximation is an R:G:B
channel exposure ratio like 1:2:3 or G and B a bit closer to the Red
exposure if blue sky background is used). Potential drawback is an
increased chance on blooming of the Red channel as exposures increase.
Because you use ImagesPlus, there might even be a possibility to
combine the R, G, and B pixels from 3 Raws and Demosaic a composite of
the three files. It may be difficult to get accurate color though,
because I don't know how the Canon libraries will react to such a
fabricated neutral exposure (the AA-filter and secondary band
transmission may/will cause unexpected results). The whole exercise
may become too involved for more than a few negatives or an
experiment.
It is almost certainly much easier to filter the light before it
reaches the sensor, with the backlight color (blue sky would already
help some) and a lens filter.
Bart |
|
| Back to top |
|
|
|
|
|
|
FAQ
Memberlist
Register
Profile
Log in to check your private messages
Log in