You're Help/Advice Please re Scanner for Slides and Negatives

  • Thread starter Thread starter Peter D
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Peter D

I have a collection of about 3000 slides. Most (Kodak Ektachrome) are still
looking great even though they are 20-30 years old. Some (cheap, no-name
slide film) are gone forever. I want to make digital copies to 'freeze' the
ones that are fine now rather than risk their loss. The slides are in a
variety of mounts -- thin glass, cardboard, and plastic.
I also have thousands of negative I want to scan. I want to create archival
quality copies of everything and then deal with editing and creating lower
res versions to share with family or for printing later. I want to automate
the process as much as possible. Storage space is not an issue. I'm very
familiar with data backup and storage. So no help is required in that area.

Do slides in glass mounts have to be scanned differently than the ones in
plastic/cardboard mounts (nothing in front of the film)?

Currently I have an HP Scanjet 4070 - 48 bit, 2400x2400 dpi Optical res, and
a slide/negative TMA that can do 4 at a time. I want to replace it with a
better flatbed+TMA or Slide Scanner. here's my options:

1) HP G4010. 96 bit, 6-colour. Optiical res 4800 x 4800. "Hardware Scanning
Resolution" 4800 x 9600 -- it's different than "interpolated", but I don't
know if the 9600 is a true resolution. I also don't know if beyond 4800
matters anyway. Scan five slides or 6 negatives at once. On sale for $120
(non-sale price $190). Can anyone comment on this scanner, it's specs, and
suitability to task. I realize it's not automated, but other than that, any
thoughts?

2) HP G4050. Same specs as above, but HP also mentions "faded colour
restoration, dust and scratch removal". It can scan 16 slides or 30
negatives at once. $180 at most places. This is my first choice if I can't
find a 4010 on sale before 11th (when sale ends).

As for Slide Scanners, tigerdirect.ca has a few.
- OpticFilm 7200 $232 - 48-bit, 7200 x 7200, and does 4 slides or 6
negatives at a time. Comes with Silverfast software. Reviews are great - 5/5
for all categories.
- Plustek 7200i is $366 and seems to be the same as the 7200, but they
mention "SilverFast 6 SE iSRD" for the software (they just say "SilverFast"
for above model)
- Alestron Prime Film 3650u. $330. It says 3600 dpi and "incorporates
DIGITAL ICE technology" and doesn't seem to have any kind of tray so it's
one slide or a film strip (possible manual feed) at a time.

At the moment I'm really leaning towards the G4050 for value and features,
but if I'm understanding correctly the slide scanners use red/white LEDs and
the SilverFast or Digital ICe technology to automatically restore colour and
remove dust and scratches. The HP doesn't. Does it matter?
 
Peter D said:
I have a collection of about 3000 slides. Most (Kodak Ektachrome) are still
looking great even though they are 20-30 years old. Some (cheap, no-name
slide film) are gone forever. I want to make digital copies to 'freeze' the
ones that are fine now rather than risk their loss. The slides are in a
variety of mounts -- thin glass, cardboard, and plastic.
I also have thousands of negative I want to scan. I want to create
archival quality copies of everything and then deal with editing and
creating lower res versions to share with family or for printing later. I
want to automate the process as much as possible. Storage space is not an
issue. I'm very familiar with data backup and storage. So no help is
required in that area.

Do slides in glass mounts have to be scanned differently than the ones in
plastic/cardboard mounts (nothing in front of the film)?

Currently I have an HP Scanjet 4070 - 48 bit, 2400x2400 dpi Optical res,
and a slide/negative TMA that can do 4 at a time. I want to replace it
with a better flatbed+TMA or Slide Scanner. here's my options:

1) HP G4010. 96 bit, 6-colour. Optiical res 4800 x 4800. "Hardware
Scanning Resolution" 4800 x 9600 -- it's different than "interpolated",
but I don't know if the 9600 is a true resolution. I also don't know if
beyond 4800 matters anyway. Scan five slides or 6 negatives at once. On
sale for $120 (non-sale price $190). Can anyone comment on this scanner,
it's specs, and suitability to task. I realize it's not automated, but
other than that, any thoughts?

2) HP G4050. Same specs as above, but HP also mentions "faded colour
restoration, dust and scratch removal". It can scan 16 slides or 30
negatives at once. $180 at most places. This is my first choice if I can't
find a 4010 on sale before 11th (when sale ends).

As for Slide Scanners, tigerdirect.ca has a few.
- OpticFilm 7200 $232 - 48-bit, 7200 x 7200, and does 4 slides or 6
negatives at a time. Comes with Silverfast software. Reviews are great -
5/5 for all categories.
- Plustek 7200i is $366 and seems to be the same as the 7200, but they
mention "SilverFast 6 SE iSRD" for the software (they just say
"SilverFast" for above model)
- Alestron Prime Film 3650u. $330. It says 3600 dpi and "incorporates
DIGITAL ICE technology" and doesn't seem to have any kind of tray so it's
one slide or a film strip (possible manual feed) at a time.

At the moment I'm really leaning towards the G4050 for value and features,
but if I'm understanding correctly the slide scanners use red/white LEDs
and the SilverFast or Digital ICe technology to automatically restore
colour and remove dust and scratches. The HP doesn't. Does it matter?

If you want the best quality with the least hassle, spend about $550 to
$1900 for a Nikon Film scanner.

After you have scanned all of your film, you can then sell the Nikon Film
Scanner on Ebay.
http://www.nikonusa.com/template.php?cat=1&grp=98

The best for 35 mm only is the Super Coolscan 5000ED. If you have 120 format
film the Coolscan 9000ED covers that. The Coolscan V ED is for 35 mm only
and is the lowest price.

Go to B&H Photo and Video for prices.
http://www.bhphotovideo.com/
 
[comments bottom-posted]

Peter D said:
I have a collection of about 3000 slides. Most (Kodak Ektachrome) are still
looking great even though they are 20-30 years old. Some (cheap, no-name
slide film) are gone forever. I want to make digital copies to 'freeze' the
ones that are fine now rather than risk their loss. The slides are in a
variety of mounts -- thin glass, cardboard, and plastic.
I also have thousands of negative I want to scan. I want to create
archival quality copies of everything and then deal with editing and
creating lower res versions to share with family or for printing later. I
want to automate the process as much as possible. Storage space is not an
issue. I'm very familiar with data backup and storage. So no help is
required in that area.

Do slides in glass mounts have to be scanned differently than the ones in
plastic/cardboard mounts (nothing in front of the film)?

Currently I have an HP Scanjet 4070 - 48 bit, 2400x2400 dpi Optical res,
and a slide/negative TMA that can do 4 at a time. I want to replace it
with a better flatbed+TMA or Slide Scanner. here's my options:

1) HP G4010. 96 bit, 6-colour. Optiical res 4800 x 4800. "Hardware
Scanning Resolution" 4800 x 9600 -- it's different than "interpolated",
but I don't know if the 9600 is a true resolution. I also don't know if
beyond 4800 matters anyway. Scan five slides or 6 negatives at once. On
sale for $120 (non-sale price $190). Can anyone comment on this scanner,
it's specs, and suitability to task. I realize it's not automated, but
other than that, any thoughts?

2) HP G4050. Same specs as above, but HP also mentions "faded colour
restoration, dust and scratch removal". It can scan 16 slides or 30
negatives at once. $180 at most places. This is my first choice if I can't
find a 4010 on sale before 11th (when sale ends).

As for Slide Scanners, tigerdirect.ca has a few.
- OpticFilm 7200 $232 - 48-bit, 7200 x 7200, and does 4 slides or 6
negatives at a time. Comes with Silverfast software. Reviews are great -
5/5 for all categories.
- Plustek 7200i is $366 and seems to be the same as the 7200, but they
mention "SilverFast 6 SE iSRD" for the software (they just say
"SilverFast" for above model)
- Alestron Prime Film 3650u. $330. It says 3600 dpi and "incorporates
DIGITAL ICE technology" and doesn't seem to have any kind of tray so it's
one slide or a film strip (possible manual feed) at a time.

At the moment I'm really leaning towards the G4050 for value and features,
but if I'm understanding correctly the slide scanners use red/white LEDs
and the SilverFast or Digital ICe technology to automatically restore
colour and remove dust and scratches. The HP doesn't. Does it matter?

I am facing the same situation, as are lots of other folks. If you buy the
equipment to do it yourself, the Nikon 5000 will cost you about $1200 and
the autoloader will cost about $500 additional. You could do it without the
autoloader, but you might end up spending the rest of your life scanning
slides and still not get done. You will want to scan at 4000DPI, and
scanning at that resolution with Digital Ice will take a long time for each
scan.

I am considering another solution - send the job out. I looked rather
extensively and kind of like digmypics.com. They charge $0.49 for 2000DPI
scans and $0.89 for 4000DPI. If you do it yourself, the equipment will cost
you around $1,700 and the hundreds of hours of your own time must be worth
something. All in, it is much cheaper to send out the job. If you're not
sure, you could send me 50 slides and see how they do. That's what I plan on
doing, when I get a chance (I have photos, slides and negs.)

What do you think?
 
I have a collection of about 3000 slides. Most (Kodak Ektachrome) are still
looking great even though they are 20-30 years old. Some (cheap, no-name
slide film) are gone forever. I want to make digital copies to 'freeze' the
ones that are fine now rather than risk their loss. The slides are in a
variety of mounts -- thin glass, cardboard, and plastic.
I also have thousands of negative I want to scan. I want to create archival
quality copies of everything and then deal with editing and creating lower
res versions to share with family or for printing later. I want to automate
the process as much as possible. Storage space is not an issue. I'm very
familiar with data backup and storage. So no help is required in that area.

Do slides in glass mounts have to be scanned differently than the ones in
plastic/cardboard mounts (nothing in front of the film)?

Currently I have an HP Scanjet 4070 - 48 bit, 2400x2400 dpi Optical res, and
a slide/negative TMA that can do 4 at a time. I want to replace it with a
better flatbed+TMA or Slide Scanner. here's my options:

1) HP G4010. 96 bit, 6-colour. Optiical res 4800 x 4800. "Hardware Scanning
Resolution" 4800 x 9600 -- it's different than "interpolated", but I don't
know if the 9600 is a true resolution. I also don't know if beyond 4800
matters anyway. Scan five slides or 6 negatives at once. On sale for $120
(non-sale price $190). Can anyone comment on this scanner, it's specs, and
suitability to task. I realize it's not automated, but other than that, any
thoughts?

2) HP G4050. Same specs as above, but HP also mentions "faded colour
restoration, dust and scratch removal". It can scan 16 slides or 30
negatives at once. $180 at most places. This is my first choice if I can't
find a 4010 on sale before 11th (when sale ends).

As for Slide Scanners, tigerdirect.ca has a few.
- OpticFilm 7200 $232 - 48-bit, 7200 x 7200, and does 4 slides or 6
negatives at a time. Comes with Silverfast software. Reviews are great - 5/5
for all categories.
- Plustek 7200i is $366 and seems to be the same as the 7200, but they
mention "SilverFast 6 SE iSRD" for the software (they just say "SilverFast"
for above model)
- Alestron Prime Film 3650u. $330. It says 3600 dpi and "incorporates
DIGITAL ICE technology" and doesn't seem to have any kind of tray so it's
one slide or a film strip (possible manual feed) at a time.

At the moment I'm really leaning towards the G4050 for value and features,
but if I'm understanding correctly the slide scanners use red/white LEDs and
the SilverFast or Digital ICe technology to automatically restore colour and
remove dust and scratches. The HP doesn't. Does it matter?


Get an Epson V700 refurbed on the Epson site for around $450, or $550
new, does slides better than older slide scanners and probably the
ones you have listed. Scanning 12 slides at a time is just the right
number, any more and you run out of memory with higher resoutions, any
less and you have to sit with the scanner, will do 24 negatives. A
good flatbed too. For better results you are looking at 2-3X the
price. The Epson has Digital Ice too, but I only use it if I have
really dirty slides. I have been very happy with mine, had it for cloe
to 2 years.

Tom
 
Re: "The Coolscan V ED is for 35 mm only and is the lowest price."

The Nikon 35mm scanners from the LS-2000 forward can all do APS film
with an APS adapter (the adapters are not terribly common, but they do
show up on E-Bay and they are not too expensive ... under $100). It
wasn't relevant to this question, but should be noted for other readers.
 
Re: "You will want to scan at 4000DPI"

I suspect that most people will scan at the highest resolution supported
by their hardware, but 2,700 DPI gives about a 10 megapixel image, and
4,000 dpi gives approximately a 22 megapixel image. 22 megapixels from
a 35mm image may truly be overkill, and may far exceed the actual detail
that exists on the average negative or slide shot with the average
camera and lens by the average photographer. But when you use 4,000 DPI
on hundreds or thousands of slides or negatives, the impact on both the
time required and the storage space required will be both real and
tremendous.
[comments bottom-posted]

Peter D said:
I have a collection of about 3000 slides. Most (Kodak Ektachrome) are
still looking great even though they are 20-30 years old. Some (cheap,
no-name slide film) are gone forever. I want to make digital copies to
'freeze' the ones that are fine now rather than risk their loss. The
slides are in a variety of mounts -- thin glass, cardboard, and plastic.
I also have thousands of negative I want to scan. I want to create
archival quality copies of everything and then deal with editing and
creating lower res versions to share with family or for printing
later. I want to automate the process as much as possible. Storage
space is not an issue. I'm very familiar with data backup and storage.
So no help is required in that area.

Do slides in glass mounts have to be scanned differently than the ones
in plastic/cardboard mounts (nothing in front of the film)?

Currently I have an HP Scanjet 4070 - 48 bit, 2400x2400 dpi Optical
res, and a slide/negative TMA that can do 4 at a time. I want to
replace it with a better flatbed+TMA or Slide Scanner. here's my options:

1) HP G4010. 96 bit, 6-colour. Optiical res 4800 x 4800. "Hardware
Scanning Resolution" 4800 x 9600 -- it's different than
"interpolated", but I don't know if the 9600 is a true resolution. I
also don't know if beyond 4800 matters anyway. Scan five slides or 6
negatives at once. On sale for $120 (non-sale price $190). Can anyone
comment on this scanner, it's specs, and suitability to task. I
realize it's not automated, but other than that, any thoughts?

2) HP G4050. Same specs as above, but HP also mentions "faded colour
restoration, dust and scratch removal". It can scan 16 slides or 30
negatives at once. $180 at most places. This is my first choice if I
can't find a 4010 on sale before 11th (when sale ends).

As for Slide Scanners, tigerdirect.ca has a few.
- OpticFilm 7200 $232 - 48-bit, 7200 x 7200, and does 4 slides or 6
negatives at a time. Comes with Silverfast software. Reviews are great
- 5/5 for all categories.
- Plustek 7200i is $366 and seems to be the same as the 7200, but they
mention "SilverFast 6 SE iSRD" for the software (they just say
"SilverFast" for above model)
- Alestron Prime Film 3650u. $330. It says 3600 dpi and "incorporates
DIGITAL ICE technology" and doesn't seem to have any kind of tray so
it's one slide or a film strip (possible manual feed) at a time.

At the moment I'm really leaning towards the G4050 for value and
features, but if I'm understanding correctly the slide scanners use
red/white LEDs and the SilverFast or Digital ICe technology to
automatically restore colour and remove dust and scratches. The HP
doesn't. Does it matter?

I am facing the same situation, as are lots of other folks. If you buy
the equipment to do it yourself, the Nikon 5000 will cost you about
$1200 and the autoloader will cost about $500 additional. You could do
it without the autoloader, but you might end up spending the rest of
your life scanning slides and still not get done. You will want to scan
at 4000DPI, and scanning at that resolution with Digital Ice will take a
long time for each scan.

I am considering another solution - send the job out. I looked rather
extensively and kind of like digmypics.com. They charge $0.49 for
2000DPI scans and $0.89 for 4000DPI. If you do it yourself, the
equipment will cost you around $1,700 and the hundreds of hours of your
own time must be worth something. All in, it is much cheaper to send out
the job. If you're not sure, you could send me 50 slides and see how
they do. That's what I plan on doing, when I get a chance (I have
photos, slides and negs.)

What do you think?
 
I decided to go with the HP G4050. Mostly because of price ($180),
convenience, and the ability to do 16 slides or 30 negatives at a time
without any additional equipment. That's enough to make it worth loading and
walking away (semi-automatic). I'll play with it once I get it, and pass on
what I learn. As I go through, I'm going to single out "spectacular"
slides/negs and send them away for professional scanning (89c each).

I wonder if anyone can advice me on the following:

1) Scanning slides in glass mounts - do I need to scan differently or do I
treat just like the other slides?

2) Best scanning resolution and colour depth - I can go to 96 bit 4800 x4800
optical ( HP says "4800 x 9600 Hardware Scanning Resolution" - whatever that
means).
 
4800 x 9600 implies that the resolution in one direction (vertical or
horizontal) is 4800 dpi and the resolution in the other direction is
9600 dpi. Optical means that this is the "true", "actual" resolution
.... you get a "real" pixel (a point actually imaged by the sensor) at
those resolutions in those directions. On the contrary, "interpolated"
resolution is resoulution where there are pixels between "real" pixels
that are "fabricated" by interpolating between the nearest "real" pixels.

The resolution in one direction is determined by the actual sensor
element (CCD, CIS element, etc.). The resolution in the other direction
is determined by the stepper motor that moves the scan head across the
material being scanned ... how fine it's steps are (how many points the
head stops at to image).

4800 x 4800 is almost too high ... that is going to give you a scanned
image (for 35mm images) of almost 32 megapixels. I'm going to go out on
a limb and say that there isn't that much detail present in ANY 35mm
images. 2700 dpi give 10 megapixels, which is a good value. In SOME
images, a SLIGHTLY higher value might be better, but for most images, 10
megapixels (2700 dpi) is going to pretty much capture everything. The
problem you have is that with a hardware resolution of 4800 x 4800, the
next lower choice that you have that uses only optical resolution is
going to be 2400 x 2400 (e.g. use every other pixel), and that is
getting to be too low (it will give about an 8 megapixel image ...
nothing to sneeze at, but more would probably be better)).
 
Thank you for your helpful information. I decided I wouldn't use any
interpolated resultions, staying with optical resolution only. From what
I've read 2700 x 2700 seems to be the 'sweet spot' for 35mm. I didn't
realise that I have to select an optical resolution that has to be divide
into the highest optical resolution. I would have liked to go with 2700 or
3000. Are you certain I have to go with 2400 if I don't want to go as high
as 4800? 2400 is fine for these slides, but I would prefer to go to 2700 or
3000, but if that would actually be worse or no better than 2400 then I
don't see the point (longer scan time, larger file size).

How about the option of using 96 bit? Would that really be better than 48
bit or is overkill?

Also, any tips on scanning slides in glass mounts?

Thanks for all your help.
 
Photoshop does a pretty good job of downsampling to whatever resolution
you want to keep. Even if you do sample some meaningless "noise" at 4800
ppi, i won't hurt you ( other than time and file space). PS bicubic
will help "average" it out.

BTW, i would be surprised if the HP ( or most any flatbed) could
actually resolve more than about 2000 ppi anyway. Any actual details
above that would be smeared if the optics were not up to resolving 2000+
ppi. The latest Epsons are around 2000-2300 ppi resolving no matter the
number of CCD elements (4800 ?). One test report has it at 2300 dpi for
the V750/V700.

http://www.filmscanner.info/EpsonPerfectionV750Pro.html
(sorry in German only - but google can translate)

http://photo.net/bboard/q-and-a-fetch-msg?msg_id=0083ZV

http://www.kenrockwell.com/tech/scantek.htm



for some background discussion. You could get a test chart (USAF 1951)
and find out what the scanner is actually capable of resolving.

Depending on the camera optics, film, and developing the film image may
not even have 2000 ppi of image information anyway.

THe main reason, as i understand it, to scan at higher resolution is to
1) be able to downsample to whatever number of pixels you want, and 2)
to be able to feed enough pixels to the printer to enlarge 8X or more
from a 35mm frame.

Regards,
 
If you have pixels spaced 1/4,800th of an inch apart (that's what 4800
dpi means), you can use every pixel, or every other pixel (every other
pixel giving only 2,400 dpi). There are no resolution choices in
between 2,400 dpi and 4,800 dpi that don't use interpolated pixels
("calculated" pixels where no actual image data exists). Below 2,400
dpi, your next choice not using interpolated pixels would be every 3rd
pixel (1,600 dpi).

Bits does not have anything to do with resolution but rather color
depth. The human eye can see (depending on which source you cite)
somewhere between 1 million and 10 million colors. Well, 24-bit color
depth is 16 million colors. More can be helpful in certain situations
involving slides with really dark areas that are still discernable as
not being solid black, but the benefit is marginal and usually of
interest only to professionals [also note that the JPEG format is only
capable of saving files in 24-bit color].

Can't help you with the glass mounts. clearly reflections from the
glass are possible and may distort your results.
 
Barry Watzman said:
If you have pixels spaced 1/4,800th of an inch apart (that's what 4800
dpi means), you can use every pixel, or every other pixel (every other
pixel giving only 2,400 dpi). There are no resolution choices in
between 2,400 dpi and 4,800 dpi that don't use interpolated pixels
("calculated" pixels where no actual image data exists). Below 2,400
dpi, your next choice not using interpolated pixels would be every 3rd
pixel (1,600 dpi).
Since none of the flatbeds mentioned in this thread so far have a TRUE
optical resolution (as opposed to an optical sampling density, which
says nothing about true resolution) better than 2000ppi, and most are
abysmally lower, it doesn't matter one iota what resolution you use
between 2400 and 4800ppi. "No actual image data exists" above 2000ppi
for any of them. They are all interpolated - its just a question of
whether they are analogue interpolated or digitally interpolated.

Stepping 1/4800th of an inch between samples doesn't give any additional
information if the optics themselves can't resolve more than 1/2000th of
an inch! Its just analogue interpolation.

So use whatever resolution you like between 2400 and 4800ppi - you
aren't going to get any more detail off the film since you have already
exceeded the true resolution of any flatbed scanner.
 
I think you are incorrect in your statement about flatbed scanners. I
think that the true optical resolution of most of the current and recent
past crops of flatbed scanners are in the range of 2,400 to 4,800 dpi.
My HP 5470C from 2002 has a maximum true optical resolution of 2,400 dpi.
 
Unless I assume that HP is faking the results or playing clever games with
the facts, the optical res of the G4050 is at least 4800x4800. The HP site
at lists the resolutions as follows:
Optical Scanning Resolution - Up to 4800 dpi
Hardware Scanning Resolution* - Up to 4800 x 9600 dpi
enhanced scanning resolution* - Unlimited

*I don't know what "Hardware Scanning Resolution" is, but I think "enhanced
scanning resolution" is another name for "interpolated" and thus "Hardware
Scanning Resolution" isn't. I presume that the stated Optical Scanning
Resolution is true unless someone can show me hard facts otherwise.

Test slides at 4800 x4800 96 bit are incredibly detailed, far beyond what I
expected, but they do take a long time -- aobut 40-50 minutes to do 16 at a
time.

As for my situation, I've decided to scan the slides at 2400, 48 bit color
depth and save them in a non-'lossy' format because I can store them
compressed as "rar" (WinRAR) and use "par" files to protect them against
loss due to damage. I'll then create jpg high quality but smaller 300 dpi
versions for ordinary printing and viewing use. If anyone thinks I should do
something different please tell me.
 
Barry Watzman said:
I think you are incorrect in your statement about flatbed scanners.

I don't think, I measure. That is why I KNOW what you THINK is wrong!
;-)
I think that the true optical resolution of most of the current and
recent past crops of flatbed scanners are in the range of 2,400 to
4,800 dpi. My HP 5470C from 2002 has a maximum true optical resolution
of 2,400 dpi.
Go on then, post a scan anywhere we can view from your flatbed HP 5470C
which RESOLVES 1200cy/in!

It would certainly be capable of that if it indeed had a true optical
resolution (as opposed to an optical sampling density) of 2400ppi.

Moving the scan head in 1/2400" steps or placing the sensels at 1/2400"
pitch does not mean the scanner can resolve 2400ppi. If the scanner
lens cannot resolve that detail then you can take samples infinitely
close together, taking and infinite time to build up an image which will
still have an optical resolution which is less than 2400ppi!
 
Peter D said:
Unless I assume that HP is faking the results or playing clever games with
the facts, the optical res of the G4050 is at least 4800x4800. The HP site
at lists the resolutions as follows:
Optical Scanning Resolution - Up to 4800 dpi
Hardware Scanning Resolution* - Up to 4800 x 9600 dpi
enhanced scanning resolution* - Unlimited
Almost ALL scanner manufacturers play "clever games with the facts"
concerning their scanner performance. At least HP are being reasonably
honest, under the circumstances, by using the terms "up to", which
should be a warning to most buyers.

Unfortunately, many years ago, one scanner manufacturer was sued for
misrepresentation of the facts in claiming 1200ppi resolution which was
actually digitally interpolated. The result was a court ruling that
when the resolution is digitally interpolated the scanner manufacturer
MUST make this clear, through the use of the term "interpolated" or
"enhanced" to distinguish it from the physical step size. The
"unfortunate" part of this saga is that the court made no ruling as to
the misuse of the terms "resolution" or "optical resolution" and this
has been exploited by manufacturers ever since - most significantly in
the flatbed area where the optics are rarely capable of resolving
anywhere close to the minimum step size of the scanner mechanism. Hence
the term "optical resolution", which gives the user the impression that
the scanner can indeed resolve detail of that size, only defines the
physical step size of the scanner and NOT the optical resolution.
Test slides at 4800 x4800 96 bit are incredibly detailed, far beyond what I
expected, but they do take a long time -- aobut 40-50 minutes to do 16 at a
time.
And are a complete waste of time on a scanner which has a true optical
resolution less than 2000ppi, as almost all consumer flatbeds do.

Compare your 4800ppi scan with a 4000ppi (or even a 2700ppi) result from
a quality dedicated film scanner and you will see precisely how much HP
(or any other flatbed manufacturer) plays "clever games with the facts".

If you don't have access to a decent flatbed, take a look at how many
flatbeds appear in any of the scanner bake-off tests that were conducted
in 2004/5. Flatbed scanner development hasn't progressed much, if at
all, since then.

If you want to scan the most detail from film for archive purposes, get
a proper film scanner. You'll see the difference on the first scan.
Anything less is a waste of time and money.
 
Test slides at 4800 x4800 96 bit are incredibly detailed, far beyond what I
expected, but they do take a long time -- aobut 40-50 minutes to do 16 at a
time.

Here's a very simple test to see if that 4800 x 4800 is "real."

Downsample a copy of the image to half that resolution,
ie. 2400 x 2400.

Then upsample back up to 4800 x 4800, and compare to
the original.

If there's no difference (which I'm fairly certain will be the case)
then there wasn't any information in the scan that couldn't be
captured at the lower resolution. Meaning that you were
carrying around 4x more pixels than were justified.

At some point (in the fist downsampling step) as you lower
that target resolution, you *will* hit a point where real detail
is lost. That is your effective resolution. Anything much
above that is wasted pixels -- data with no information.


rafe b
www.terrapinphoto.com
 
Kennedy McEwen said:
I don't think, I measure. That is why I KNOW what you THINK is wrong!
;-)

Then please provide a file or recent study or set of facts or measurements
that supports your claim. After all, so far your "KNOW" is just a fancy
"THINK" tosed out with the hope the reader will presume authority or
expertise on your part sufficient to be accepted as "gospel". Me, I'm a
skeptic, and I read an "opinion". And I figure on USEnet opinions are like
arses. Everyone has one. And everyone thinks theirs smells the sweetest. :-)
 
Peter D said:
Then please provide a file or recent study or set of facts or measurements
that supports your claim. After all, so far your "KNOW" is just a fancy
"THINK" tosed out with the hope the reader will presume authority or
expertise on your part sufficient to be accepted as "gospel". Me, I'm a
skeptic, and I read an "opinion".

First, take a look at the scanner bake-off tests I referred to earlier.
You won't find your HP 5470C even qualifies the entry level, let alone
matches the capabilities of dedicated film scanners claiming similar
resolution.

Don't believe that? Well try the second approach: download and test a
copy of Imatest and tell us what the MTF50 is for your HP scanner.

Still not convinced? For a third piece of evidence, try Rafe's test. It
isn't a black and white distinction, since scanners which come close to
their rated resolution will show some degradation after downsampling and
upsampling. However, yours is so far off the mark you won't have to
worry about such esoteric finesse.

Fourthly, try searching this newsgroups archives on resolution and you
will not only find enough studies and samples to satisfy your quest for
evidence, you will discover that the credentials of your correspondent
are impeccable in this respect.

Remember, you are making the claim that your scanner exceeds the
capabilities of any 2400ppi flatbed scanner on the market. Not one of
them comes close to resolving 2400ppi when they are actually measured,
but somehow you think you have found something special that has escaped
all other measurements. Prove it does. No matter how much evidence I
provide, you only need to show one scan to disprove it. Go on. Do it!
And I figure on USEnet opinions are like
arses. Everyone has one. And everyone thinks theirs smells the sweetest. :-)
Yep, and you are demonstrating yourself to be one of the biggest! ;-)
 
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