Scanning 35mm Slides

In the past Costco has been able to scan my slides and make prints and
enlargements for a very reasonable cost about three dollars for a 12X18.
They have a new processing machine which has done a great job on my Digital
Enlargements and my own medium format scans that I do on my old Epson 2450.
The Epson 2450 is just not cutting it on the 35mm slides However, my slides
come out with bad color balance and fuzzy with the new machine from Costco.
They say that they have tried to get it fixed, but because there are so few
people with slides now that it is not a priority. I know that there are
other photo places that I can use, but they are much more expensive. I was
wondering if the Minolta IV scanner at 3200dpi would give good enough
results to have a slide enlarged to 12x18. I am shooting Kodak VS100 slide
film. Thanks for the info. Matt

"MATT WILLIAMS" wrote in message
...
In the past Costco has been able to scan my slides and make prints and
enlargements for a very reasonable cost about three dollars for a 12X18.
They have a new processing machine which has done a great job on my
Digital
Enlargements and my own medium format scans that I do on my old Epson
2450.
The Epson 2450 is just not cutting it on the 35mm slides However, my
slides
come out with bad color balance and fuzzy with the new machine from
Costco.
They say that they have tried to get it fixed, but because there are so
few
people with slides now that it is not a priority. I know that there are
other photo places that I can use, but they are much more expensive. I was
wondering if the Minolta IV scanner at 3200dpi would give good enough
results to have a slide enlarged to 12x18. I am shooting Kodak VS100 slide
film. Thanks for the info. Matt


Minolta IV at full resolution gives a file of 79-80 Mb. I havent tried
printing yet, but the slide scans from it are very good. If you want samples
email me

Any of the current Minolta or Nikon slide scanners (2400 dpi or better)
should be MUCH better than an Epson flatbed scanner. They will pick up all
the detail in the slide; whether the slide is sharp enough for a large print
is up to you!

I have both a Nikon Coolscan (of a few years back) and a new Epson flatbed
with illuminated slide scanner. The Nikon does a much better job on
slides -- as it should -- that's what it's designed for.

On Fri, 25 Jun 2004 13:17:51 GMT, "MATT WILLIAMS"
wrote:

In the past Costco has been able to scan my slides and make prints and
enlargements for a very reasonable cost about three dollars for a 12X18.
They have a new processing machine which has done a great job on my Digital
Enlargements and my own medium format scans that I do on my old Epson 2450.
The Epson 2450 is just not cutting it on the 35mm slides However, my slides
come out with bad color balance and fuzzy with the new machine from Costco.
They say that they have tried to get it fixed, but because there are so few
people with slides now that it is not a priority. I know that there are
other photo places that I can use, but they are much more expensive. I was
wondering if the Minolta IV scanner at 3200dpi would give good enough
results to have a slide enlarged to 12x18. I am shooting Kodak VS100 slide
film. Thanks for the info. Matt


The normal figure used for printing is 300 dpi and you can get by with
a bit less. An 18 inch print at 300 dpi is 5400. Divide by 1.5 (the
length of a 35 mm slide or negative) and you get 3600 dpi. That means
the Coolscan IV should be close at full frame.
Going the other way 3200 * 1.5 = 4800/18=~267 dpi or about 9% shy of
the desired dpi.

At those figures I can't see the difference, but there are those who
claim they can make a big difference.

"To me" the figure would be sufficient unless I were making prints for
exhibition, competition, or sale. In that case I'd be looking at the
Minolta 5400 or Nikon LS5000, or one of the other high resolution
scanners.

Roger Halstead (K8RI & ARRL life member)
(N833R, S# CD-2 Worlds oldest Debonair)
www.rogerhalstead.com

"Roger Halstead" wrote in message
...

The normal figure used for printing is 300 dpi and you can get by with
a bit less. An 18 inch print at 300 dpi is 5400. Divide by 1.5 (the
length of a 35 mm slide or negative) and you get 3600 dpi. That means
the Coolscan IV should be close at full frame.
Going the other way 3200 * 1.5 = 4800/18=~267 dpi or about 9% shy of
the desired dpi.

At those figures I can't see the difference, but there are those who
claim they can make a big difference.

"To me" the figure would be sufficient unless I were making prints for
exhibition, competition, or sale. In that case I'd be looking at the
Minolta 5400 or Nikon LS5000, or one of the other high resolution
scanners.

My Coolscan III captures everything that's on the slide. In fact I usually
use it at half resolution (1350 dpi) to hide grain. Remember that digital
sharpening will bring out more picture detail than the dpi numbers suggest.
I have no qualms about using this scanner for exhibition prints.

In article ,
Roger Halstead wrote:
The normal figure used for printing is 300 dpi and you can get by with
a bit less. An 18 inch print at 300 dpi is 5400. Divide by 1.5 (the
length of a 35 mm slide or negative) and you get 3600 dpi. That means
the Coolscan IV should be close at full frame.
Going the other way 3200 * 1.5 = 4800/18=~267 dpi or about 9% shy of
the desired dpi.

You have to take scanner optics into account as well. If the scanner
optics are perfect, you get aliasing errors. If the optics are poor,
you don't get anywhere near the computed resolution.

Scanning at a much higher resolution than you actually need, followed by
downsampling is a good idea.



--
The Electronic Monk was a labor-saving device, like a dishwasher or a video
recorder. [...] Video recorders watched tedious television for you, thus saving
you the bother of looking at it yourself; Electronic Monks believed things for
you, [...] -- Douglas Adams in Dirk Gently's Holistic Detective Agency

On Fri, 25 Jun 2004 21:39:52 -0400, "Michael A. Covington"
wrote:


"Roger Halstead" wrote in message
.. .

The normal figure used for printing is 300 dpi and you can get by with
a bit less. An 18 inch print at 300 dpi is 5400. Divide by 1.5 (the
length of a 35 mm slide or negative) and you get 3600 dpi. That means
the Coolscan IV should be close at full frame.
Going the other way 3200 * 1.5 = 4800/18=~267 dpi or about 9% shy of
the desired dpi.

At those figures I can't see the difference, but there are those who
claim they can make a big difference.

"To me" the figure would be sufficient unless I were making prints for
exhibition, competition, or sale. In that case I'd be looking at the
Minolta 5400 or Nikon LS5000, or one of the other high resolution
scanners.

So, we get two posts from the opposite ends of the spectrum:-))
I will add that what the user sees depends on the actual scanner.
So what ever works in each case... Go for it.

My Coolscan III captures everything that's on the slide. In fact I usually
use it at half resolution (1350 dpi) to hide grain. Remember that digital

2700 dpi should not be capable of capturing any where near all the
information on the slide unless it's very high speed film.

sharpening will bring out more picture detail than the dpi numbers suggest.
I have no qualms about using this scanner for exhibition prints.

Phillip said it better than I could about the optics.

Sharpening can not bring out more detail than is there in the first
place although it can make things look better.

How things look at 2700 or 1350 depends more on the physical
characteristics of the scanner, but you should not have to scan at
half resolution to hide grain unless it's coming from the scanner and
not the slide.

I have no problem with film grain at 4000 dpi, except on ASA 400 and
higher slides I can see the clumping and patterns when enlarging
greatly.

Again, I agree with Phillip that scanning at a higher resolution than
needed and down sampling gives better results than scanning at a
lesser resolution.

Roger Halstead (K8RI & ARRL life member)
(N833R, S# CD-2 Worlds oldest Debonair)
www.rogerhalstead.com

"Roger Halstead" wrote in message
...

My Coolscan III captures everything that's on the slide. In fact I
usually
use it at half resolution (1350 dpi) to hide grain. Remember that
digital

2700 dpi should not be capable of capturing any where near all the
information on the slide unless it's very high speed film.

2700 dpi is more than 100 lines per mm, more than 50 line pairs per mm.
Photographs taken under normal conditions seldom resolve this much. Under
ideal conditions, an excellent lens will resolve 80 line pairs per mm, but
that's exceptional.

Sharpening can not bring out more detail than is there in the first
place although it can make things look better.

But it can bring out detail that you absolutely could not see. I do this
kind of thing regularly with astronomical photographs.

How things look at 2700 or 1350 depends more on the physical
characteristics of the scanner, but you should not have to scan at
half resolution to hide grain unless it's coming from the scanner and
not the slide.

It's real film grain (Ektachrome 200, typically).

Again, I agree with Phillip that scanning at a higher resolution than
needed and down sampling gives better results than scanning at a
lesser resolution.

In theory, yes. But it depends on the MTF of the entire system. I get
satisfactory results for most purposes -- not super-large exhibition
prints -- by scanning at half resolution on my Coolscan III.


Clear skies,

Michael A. Covington
Author, Astrophotography for the Amateur
www.covingtoninnovations.com/astromenu.html

In article , Michael A.
Covington writes

"Roger Halstead" wrote in message
.. .

My Coolscan III captures everything that's on the slide. In fact I
usually
use it at half resolution (1350 dpi) to hide grain. Remember that
digital

2700 dpi should not be capable of capturing any where near all the
information on the slide unless it's very high speed film.

2700 dpi is more than 100 lines per mm, more than 50 line pairs per mm.
Photographs taken under normal conditions seldom resolve this much.

MTF charts for Velvia show an MTF of 50% at 50cy/mm, for Provia & Sensia
it is more typically 30% (as it is for the E-200 you refer to below),
which is certainly not negligible and a long way short of their limiting
resolution.

Under
ideal conditions, an excellent lens will resolve 80 line pairs per mm, but
that's exceptional.

A decent lens will easily have an MTF of around 80% on axis for 50cy/mm
at f/8 or faster. At the frame edges and corners it would typically be
down on this, but not to the point of being negligible.

So, a tripod mounted camera shooting Fuji Velvia should easily reproduce
detail on the film at a transfer function of around 40% of the scene at
the limiting resolution of your LS-30 scanner. With a 2700ppi scanner,
the MTF at 50cy/mm is unlikely to exceed 50%, so 50% of the information
recorded on the film at the scanner's limiting resolution is lost - even
more if you halve the intrinsic resolution of the scan to 1350ppi! In
either case, that still leaves a significant amount of detail recorded
on the film that the scanner cannot reproduce without aliasing.

How things look at 2700 or 1350 depends more on the physical
characteristics of the scanner, but you should not have to scan at
half resolution to hide grain unless it's coming from the scanner and
not the slide.

It's real film grain (Ektachrome 200, typically).

If its E-200 and an LS-30 then it definitely is *not* real grain! Just
have a true chemical 16x20" print made from any of your slides and
compare that to a similar size inkjet, or digital/chemical print created
from a scan off your LS-30 and the difference in grain size, structure
and perception between the two images is striking.

I certainly am not talking theoretically here Michael, I have actually
done this comparison both with slides and negatives, having made the
prints in my own darkroom with traditional methods.

The vast majority of the grain you see on the 2700ppi scan is aliased by
the scanner itself - and the light system and MTF curves of the Nikon
scanner range make them particularly prone to this. Its visibility
will, of course, be reduced by correctly downsampling to 1350ppi as your
workflow implements, but not without significant loss of real image
content as well.

Moving to the 4000ppi of the LS-4000 from my immediate predecessor
scanner the LS-2000 (same resolution as the LS-30, just more bits and
better features) the single biggest change in scan quality was the
perception of grain due, in the most part, to a massive reduction in
grain aliasing. Increased resolution was less significant but very
noticeable nonetheless. You can print the 4000ppi image directly
without need to downsample and get a perceived granularity very similar
to the chemical print. By applying a little filtering, such as GEM or
NeatImage (not too much!) you can get a print from the scan which is
actually cleaner than any chemical print yet with almost as much
resolution. Furthermore, 4000ppi is not even the limit of what can be
on the film with a good lens setup, as users of the Minolta 5400 scanner
will testify and can be verified with a professional drum scan. Such
results are simply impossible from 2700ppi scanners, good though some of
them indisputably were.
--
Kennedy
Yes, Socrates himself is particularly missed;
A lovely little thinker, but a bugger when he's ****ed.
Python Philosophers (replace 'nospam' with 'kennedym' when replying)

Interesting. I will keep in mind your point about grain aliasing. It may
be analogous to a phenomenon I observed with conventional enlarging:
out-of-focus grain still looks like grain, but bigger (coarser).