Is the EPSON 4990 really 16 bit?

  • Thread starter Thread starter Oliver Kunze
  • Start date Start date
No problem - anmd now I'm back late myself, being kinda busy... (getting
my travel/photography archive organized in preparation for scanning 20
years' worth of photographs!)

Turned out the public news server I use had some serious trouble
getting the messages in order from his sources - got your message a
day later than the answer I answered to.
I don't think a whole image is needed, just a small crop that shows the
grain should do - and preferably in a lossless format (I've been
confused several times by JPEG artifacts already)

They are on the way, hopefully you can get about 8.8 MB in e-mail with
that anti-spam address.
 
rafe b (rafebATspeakeasy.net) wrote in
Ultimately, whether the noise is grain or electronic (sampling) noise,
is irrelevant, IMO.

Not having any experience with this yet, and given the different
characteristics of both, I wonder if there may be different approaches
to post-processing (after scanning) to get rid of either/both.
The *only* disadvantage to shooting C41, for my purposes, is the
noise.

Are you saying scanning C41 will result in more noise than scanning
chrome? If so, why is that?
Personally,
I call it a good tradeoff, considering the
other benefits of C41, including but not
limited to:

* better latitude (exposure range)
* lower Dmax (easier to scan)
* better acutance

Latitude is a biggie for me, given that I'm doing mostly travel
photography, not in control of lighting, and often having to shoot *now*
because (say) tomorrow at noon (when the light will be better) I may be
somewhere else already. It's often not easy to to come back at all,
ever. So deliberately underexposing and hoping there will be enough
information on the negative to pull something reasonable out of it is
not uncommon (which is how I got the very underexposed negatives I
mentioned); at the same time, seriously high-contrast lighting can
happen, too (Jokhang monastery in Lhasa last October - my camera was at
times getting very confused about exposure due to the high contrasts).
Obviously, there are commercial/professional situations where only a
chrome will do.

Sure. But I'm not a "pro" (I might sell something, maybe, but I'm not
making a living off of it), I don't have a studio let alone control
lighting, and I don't have customers demanding "objectively accurate"
color. (Though I can be pretty demanding myself. :))

And I'm not ready to switch to digital either (though I'm enjoying using
my quite capable camera phone "on the side" and for quite different
things than I use my regular camera for).
 
Evo2Me ([email protected]) wrote in 4ax.com:
They are on the way, hopefully you can get about 8.8 MB in e-mail with
that anti-spam address.

After the usual "effortless pills offers", stock options and a number of
lotteries I won (again), there it was. Spammotel is really quite reliable!
:)

Thanks for taking the effort to mail these - I'll have a good look at them
later (maybe after the weekend, I'll probably be away for a few days).
 
rafe b (rafebATspeakeasy.net) wrote in


Not having any experience with this yet, and given the different
characteristics of both, I wonder if there may be different approaches
to post-processing (after scanning) to get rid of either/both.


Are you saying scanning C41 will result in more noise than scanning
chrome? If so, why is that?


Because C41 transparencies have a much
lower Dmax on the negative. You will
see this in your scanner histograms.

A contrasty chrome may well have a
dynamic range that exceeds the scanner's
range, but a C41 transparency never will.

In fact, with C41 you have the opposite
problem, in that you will likely be
using only a fraction of the available
tonal range of the scanner.

Now: regardless of the input material,
you will eventually map the codes (tones)
from the input material to the full RGB
range -- either in the scanner driver,
or in your image editor, or both.

So, for chromes, this "tonal expansion"
is much lower than it is for color
negatives. And this tonal expansion
will amplify any inherent noise in the
imaging system.

Example: if the input material only
occupies, say 64 of the available 256
available codes, and the median noise
is, say +/- 2 codes, then when you
do a 4:1 expansion of the raw image
(64 codes -> 256 codes) you now have
a median noise level of 8 codes.

To be clear: this is not a sharpness
issue, it is an issue with tonal noise.

The good news is that Nikon scanners
have a true analog gain control, which
can help the normalize and widen the
histograms of the three color channels,
independently. You will find that
red needs the least gain, green needs
more, and blue needs the most.

In terms of post processing, you should
check out NeatImage or Noise Ninja or
something similar. I use NeatImage,
and it is quite effective.


rafe b
www.terrapinphoto.com
 
Marjolein Katsma said:
Are you saying scanning C41 will result in more noise than scanning
chrome? If so, why is that?
Lots of reasons, but the main one is that the image recorded on negative
film has a compressed dynamic range, ie. reduced contrast, whilst on a
chrome the dynamic range is slightly stretched. This is why chromes are
more punchy and have less latitude than negatives. The downside is that
when you print or scan the negative you have to stretch that contrast
back out to the original range in the scene - and in the process you
also increase the contrast of the grain on the film and the noise of the
scanner.
Latitude is a biggie for me,

That is the trade-off you are making. You don't get latitude without
increasing grain contrast - if you are happy with it, then its the right
trade, but try chromes to be sure its the right trade for you.
 
Kennedy's right about the tradeoff.

You can minimize the increased grain of C41 by overexposing it
slightly- try shooting 400 speed film at 320 and processing it
normally. It won't be as smooth as a 100 speed slide film, but you
might be surprised at how well it holds up under enlargement.
 
rafe b (rafebATspeakeasy.net) wrote in
So, for chromes, this "tonal expansion"
is much lower than it is for color
negatives. And this tonal expansion
will amplify any inherent noise in the
imaging system.

Aha - very good explanation. That makes sense. Thanks.
In terms of post processing, you should
check out NeatImage or Noise Ninja or
something similar. I use NeatImage,
and it is quite effective.

Both on my list to test. For now I'm getting familiar with Paint Shop
Pro's Digital Camera Noise Reduction which can be quite effective, but
can also "overdo" things or produce artifacts (not always directly
visible without magnification, but they can be "enhanced" by other
processing steps). But there are quite a few controls, so using them
well takes a lot of practice. I'd like to know what I *have* before
starting to test third-party filters.
 
Kennedy McEwen ([email protected]) wrote in
The downside is that when you print or scan the negative you have to
stretch that contrast back out to the original range in the scene -
and in the process you also increase the contrast of the grain on the
film and the noise of the scanner.

Effectively the same explanation rafe gave - makes sense to me, thanks.
That is the trade-off you are making. You don't get latitude without
increasing grain contrast - if you are happy with it, then its the
right trade, but try chromes to be sure its the right trade for you.

Oh, I'm sure. :) Difficult lighting conditions can happen quite often
when you can't plan to be somewhere (again) at the "right" time of day,
or sit around waiting for the sun to appear one more time before sunset,
because you're moving again. Of course when I *can* do this to get a
better shot, I often will - even convince a room mate to get up at 5:30
in the morning to walk along the river for an hour so that we'll be by
that bridge when the sun is just right (it was!), but often it's just
not possible. I've been in situations where a travel mate could throw
away his slides while I could get decent prints from my negatives.
 
Roger S. ([email protected]) wrote in @g47g2000cwa.googlegroups.com:
You can minimize the increased grain of C41 by overexposing it
slightly- try shooting 400 speed film at 320 and processing it
normally. It won't be as smooth as a 100 speed slide film, but you
might be surprised at how well it holds up under enlargement.

That's something I remember from my photography classes long ago - but
it referred to B&W. I wasn't sure if this applied to color equally.

But it reminds me of my plan to do some bracketing shots (+/-2 stops)
when testing films - would that approach make sense?

One problem (for me) with Fuji Reala is that it comes only in one speed
(100 ISO), and some of the other candidates have only one speed as well,
which means I won't have a "family" to choose different speed films from
for use in different circumstances.

Then again I've been wondering if I could treat Reala as say 125 or 160
ISO (could that increase grain size?) - which triggered the idea of
doing some bracketed shots with all candidates to see how they do, both
under- and overexposed.

Decisions, decisions....
 
Then again I've been wondering if I could treat Reala as say 125 or 160
ISO (could that increase grain size?) - which triggered the idea of
doing some bracketed shots with all candidates to see how they do, both
under- and overexposed.


There are no slower C41 films that I am aware of.
Back 15 years ago there was Kodak Ektar, but no
longer.

If you want faster, just go with Fuji NPS or NPC
or the Pro-160 films, or Kodak Portra.

AIUI, C41 process isn't easy to push or pull
as E6 is. Me, I'm content with ISO 100, in fact
I wish there were slower C41 emulsions.


rafe b
www.terrapinphoto.com
 
rafe b said:
There are no slower C41 films that I am aware of.
Back 15 years ago there was Kodak Ektar, but no
longer.
That's a coincidence - I just discovered a roll of Kodak Ektar 1000 at
the back of the fridge today, dated October 1993! ;-)
 
I would shoot Reala at ISO 80 or 100 and definitely not higher if
you're going to develop normally, as you will just push more of the
image into the grainy shadow area. If you want more grain, shoot a
faster film. NPH and NPZ are similar 400 and 800 speed films. I
recommend NPZ at 640. If you want more tightly controlled grain, try
Natura 1600, which is Japan market only, but readily available on the
web. I just ordered 3 rolls.

Bracketing is fine, but I don't think you will find any benefit in
underexposing color negative film. The best thing bracketing will do
is tell you how accurate your meter is and whether a given film likes
to be shot at box speed or overexposed.
 
rafe b (rafebATspeakeasy.net) wrote in
If you want faster, just go with Fuji NPS or NPC
or the Pro-160 films, or Kodak Portra.

That, plus Reala, is prety much my shortlist to test.

I'll have to do a review of recent trips (all with Agfa portrait, which is
160) to see to what extent 100 instead of 160 would be more of a problem.
 
Marjolein Katsma said:
Kennedy McEwen ([email protected]) wrote in


Oh, I'm sure. :) Difficult lighting conditions can happen quite often
when you can't plan to be somewhere (again) at the "right" time of day,
or sit around waiting for the sun to appear one more time before sunset,
because you're moving again. Of course when I *can* do this to get a
better shot, I often will - even convince a room mate to get up at 5:30
in the morning to walk along the river for an hour so that we'll be by
that bridge when the sun is just right (it was!), but often it's just
not possible. I've been in situations where a travel mate could throw
away his slides while I could get decent prints from my negatives.
I think it is the general concept behind your argument that worries me.
In all the years I have been doing photography I have never found that
the latitude of negative film got me out of low light situations for
single or a few shots on a roll. I have shot entire rolls uprated and
then push processed them to recover the detail, but that is a different
situation. I have never found the need to use the latitude of the film
to deliberately underexpose sections of a roll, and I don't believe I
would be happy to do so either.

On the other hand, the latitude of colour negative film has enabled me
to capture much more subtle tonal ranges than is possible with slides
and helped me escape from a couple of screw ups where I didn't get the
backlighting compensation right - though the advent of TTL meters in
cameras reduced that problem.

Something worries me that you are consciously doing this instead of just
spooling back the current roll and loading up a faster film - or just
buying another body. You will get better results with a film shot at
its rated speed than you could ever achieve by fixing under-exposure at
the printing/scanning stage, especially as you have little control over
the process on colour films. I have, at times, operated 5 camera bodies
each with different films in them for this very reason - and that was in
days long before you could pick them up on ebay for less than a couple
of rolls of Velvia. ;-)
 
Straightforward only if you actually *have* any slides, and dense ones in
particular. I don't. :)

You see, I just knew all those bad shots of mine in underlit
conditions, will come in handy one day! ;o)

Don.
 
Roger S. ([email protected]) wrote in @g47g2000cwa.googlegroups.com:
Bracketing is fine, but I don't think you will find any benefit in
underexposing color negative film. The best thing bracketing will do
is tell you how accurate your meter is and whether a given film likes
to be shot at box speed or overexposed.

It's the latter that is my concern (and the opposite): how does the film
handle being under- or overexposed. The bracketing would be my testing
tactic to find out and compare with other films.

I don't want more grain (the smaller teh better) - but I do want tolerance
to (mostly) underexposure. I'll have a go through shots from recent trips,
but as far as my memory serves, (forced) underexposure happens more often
than overexposure.
 
Kennedy McEwen ([email protected]) wrote in
That's a coincidence - I just discovered a roll of Kodak Ektar 1000 at
the back of the fridge today, dated October 1993! ;-)

Heh, I have a few old rolls of film, well past their use-by date, that
have mostly been sitting quietly in the fridge. One (FujiColor HR 400)
carries a note that it hasn't been refrigerated properly (don't know for
how long). Would be fun to experiment with them a little.

The oldest is a color roll film that mentions a lab (in NL) and a process
that I doubt even exists any more!
 
Kennedy McEwen ([email protected]) wrote in (e-mail address removed):
I have never found the need to use the latitude of the film
to deliberately underexpose sections of a roll, and I don't believe I
would be happy to do so either.

I'm never happy to do so either - but it's simply a matter of getting a
shot at all or not. Here's a real example (one of the worst situations
though):

Late afternoon, you find the street back where you wanted to go take
some pictures - and it's pouring with rain, under a very heavily cloded
sky; teh street is narrow, lined with multi-story buildings and some
trees. There's a film in the camera, nowhere near full. I'm not planning
to shoot a whole roll of film in that one street anyway. No tripod or
even monopod. And by tomorrow I'll be hundreds of kilometers away.

What would you do?

If the light had been perfect I might have shot half a roll of film (the
rest of what I had in the camera or so). Even in perfect light a whole
roll would have been extremely unlikely.

What I did was underexpose 2 stops, use the widest aperture and shoot
anyway at 1/15s or 1/20s. And I took 2 or three shots. Hoping there
would be *something* at least on those negatives to remind myself why I
hope I may be able to return there once in my life, and be lucky enough
to get better weather. It's not going to be this year, that much I know.
Something worries me that you are consciously doing this instead of
just spooling back the current roll and loading up a faster film - or
just buying another body.

I did that *once*. Carried two bodies (actually two sets, both with two
lenses), and extra, faster film loaded in the other body. And indeed it
did enable me to take some pictures I would not otherwise have been able
to take.

But I said: no more. If you're traveling around for a whole month, with
limitations on the amount of weight that can be carried on international
flights and even stricter limits on what can be carried on internal
flights, and with extra rolls of film since you don't know beforehand
which speed you're going to need, or how much of it, all wrapped in
heavy lead-lined bags because X-ray machines on big international
airports may be trusted these days but those on small internal ones in
third-world countries may not ... that's a LOT of extra weight to carry
around. And I must be able to carry it all by myself, and I do mean
*carry*, maybe walking a few kilometers to teh nearest bus station.

I don't take these trips *just* to take photographs. I travel mainly to
visit other cultures and enjoy nature. And it's nice to be able to take
pictures of that. But I *need* to be able to travel light. I know
perfectly well that means I cannot always take the perfect shots I could
*theoretically* take - but it really becomes 'just theory' in such
circumstances. Reality is different.

Everything is a compromise - I just try to get the best compromise I can
carry. ;-) That is *not* two camera sets, or even tow camera bodies. And
a flash. And a tripod. And twice as much film as I already take. What it
is (for now) is a single body, a single zoom (28-300, and I do wish I
could afford a better one), the camera's built-in flash, and a monopod
that doubles as a walking stick. I am thinking of carry a few extra
rolls of faster film - but often it's just not practical to spool back
the film, take 15 shots on a faster film, spool back that film, and put
in a new regular one again. People may be waiting for me. We may need to
catch a train, or be off the road before dark, because it's too
dangerous to drive on after dark. (I used to carry a small compact
camera to serve as a possible backup, but my camera phone has taken over
that function.)
You will get better results with a film shot at its rated speed than
you could ever achieve by fixing under-exposure at the
printing/scanning stage, especially as you have little control over
the process on colour films.

Sure. I know that. That's the theory.
I have, at times, operated 5 camera bodies each with different films
in them for this very reason

And *carried* all of that gear, plus luggage for 1 - 2 month's worth
travelling in wildly different temperatures, for up to a few kilometers?
(Forget wheels - they may work on some roads and then they're a big help
but not on all terrains - sometimes you really have to *carry*, period.
So your luggage has to be light enough to make that possible.)
Somehow I don't think so...
 
Consider supplementing your main film camera with a digital P&S like
the Fuji F10- with adjustable ISO (up to 1600) and a zoom lens, it will
help you in situations like that, and the quality should be a heck of a
lot better than neg. film underexposed 2 stops and blow away your
camera phone.
 
Kennedy McEwen ([email protected]) wrote in (e-mail address removed):


I'm never happy to do so either - but it's simply a matter of getting a
shot at all or not. Here's a real example (one of the worst situations
though):

Late afternoon, you find the street back where you wanted to go take
some pictures - and it's pouring with rain, under a very heavily cloded
sky; teh street is narrow, lined with multi-story buildings and some
trees. There's a film in the camera, nowhere near full. I'm not planning
to shoot a whole roll of film in that one street anyway. No tripod or
even monopod. And by tomorrow I'll be hundreds of kilometers away.

What would you do?


That's easy. Shoot digital.

Seriously, one of the greatest
advantages of digital capture is
the ability to choose ISO setting,
on a frame-by-frame basis.

There's no free lunch of course,
even in digital high ISO equals more
noise. But at any given ISO, digital
capture is far less noisy than film.


rafe b
www.terrapinphoto.com
 
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