DSLR vs P&S a replay of Film vs Digital?

Chris Malcolm wrote:
What you get from these things is more than just help in getting a
specific shot right. You also acquire an education through using
them. In that respect you get a useful extra from the live view
histogram, which is seeing how it changes dynamically as you punt the
EV back and forth. In a few seconds you can see at a glance what it
would take at least minutes of experimental snapping and chimping to
discover, if you could be bothered to make the effort.

That is a really good point that might be well to
generalize. It is true of virtually all of the high
tech facilities provided on modern digital cameras.

While it is certainly possible, and historically was
done, to learn about composition, exposure, etc etc
without any of these new tools, it takes longer and may
not even be possible for some people.

But with the rapid feedback loops that characterize
every part of digital photography, the learning process
for *many* things is just so much quicker than it was
with film. Things that everyone did, but took days to
do, can now be done with iteration times in the minutes
or seconds range.

One example that I just *love* is EXIF data, simply
because I was never good at taking notes on exposures,
never mind things like which lenses! That alone has
increase my ability to learn more and learn quicker
about any number of small things like techniques, that
add up to significantly better results across the board.

--
Floyd L. Davidson http://www.apaflo.com/floyd_davidson
Ukpeagvik (Barrow, Alaska)

"David J Taylor" wrote:
Floyd L. Davidson wrote:
[]
I was referring to the curves on Kodak's webpage, at this
URL,

http://www.kodak.com/global/en/profe...002_0357ac.gif

which shows a plotted range from about -3.7 to 0.0, and with no signs of
saturating at 0.0.

The dynamic range is determined by the DENSITY,

DN = 20 log 10^(dmax - dmin) dB

That is, over on the left vertical axis. It does not
run from minus numbers to 0.

[]
We should make it very clear too that Kodak is not
showing higher densities because the characteristic
curves do cover the range that is actually *used* when
generating photographs. The fact that it is possible to
get a photographically useless negative with a higher
dynamic range is not signficant. The question at hand
is which provides a photographer with more dynamic
range, film or digital.

Well, that's not how I was looking at it. Film can record a greater
dynamic range, even if conventional processing can capture that easily.

The dynamic range of film is not divorced from the
processing of that film. Nor is it removed from use of
the film. We are talking about photography, not light
detection. Just as film can be used for purposes other
than photography, and exhibit different charactersics in
that use, so can electronic sensors.

There are sensor systems that go over 100 dB in dynamic
range, if you want apply *your* perception of how film
should be rated!

I am agreeing with you that 12-bit digital may beat film, but I don't
accept that 10-bit digital does, when film is used to its limits.

You are now backed down to something that is merely the
fact that you literally do not know what the definition
of dynamic range for a film is. Go back to the graphs,
and determine the range of data captured on the film,
not the range of data available in the scene...

Those graphs don't show anything near approaching 1000:1.

[]
Which is to say, for those who want to argue that film
has more dynamic range, Tri-X and other print films are
not the direction to point. Slide film has *significantly*
higher dynamic range.

.. and probably greater than your 10-bit limit!

Yes, slide film is commonly greater than *your* 10-bit
*limit*.

I never suggested any limitation at 10 bits, *you* did.

--
Floyd L. Davidson http://www.apaflo.com/floyd_davidson
Ukpeagvik (Barrow, Alaska)

"David J Taylor" wrote:
Floyd L. Davidson wrote:
[]
If nobody is pleased with the results, it isn't valid.
The point from the start was which provides a
*photographer* with higher dynamic range, film or
digital. Photographers take pictures. No picture, not
valid.

I am not going to waste further time arguing with you on this one. It is
clear to me, from the graphs we have both found, that film does have more
dynamic range then 1000:1, although it may take a different exposure than

Okay, you simply don't know what the definition of the
dynamic range of film is. You can't read the graphs.

is conventionally used, and a better than average negative scanner to take
advantage of the range.

It's quite possible that our definitions of dynamic range differ - and I
think we have had this discussion before.

Yes it does differ. I use the one that is well known,
you are not.

And in case anyone is not sure, no, I am /not/ advocating a return to
film!

Hmmm... I hadn't assumed that you were, but to be
honest I hadn't really noticed that you were not. It is
pleasing to see you bring that up! I think it is very
unfortunate that your arguments do help others with a
touch of neo-Luddite mindset, but that is *their*
problem not yours.

--
Floyd L. Davidson http://www.apaflo.com/floyd_davidson
Ukpeagvik (Barrow, Alaska)

Floyd L. Davidson wrote:
[]
Yes, slide film is commonly greater than *your* 10-bit *limit*.

Thanks for now agreeing with me.

Cheers,
David

Floyd L. Davidson wrote:

We aren't looking at the same graphs. You appear to be
looking at the curves given on Norman Koren's webpage,
at

http://www.normankoren.com/digital_t...#Dynamic_range

Sorry, I thought we had been talking about that one.



The DENSITY axis ranges from 0 to 4.0, and the curve is
plotted from about 0.3 to roughly 2.8. That is a
dynamic range of 2.5. That is what I am calculating it
with, though I was just ignoring the lower end, as if it
were 0.0, and used a range of 2.8.

I had thought we were talking about the range of light value
the film was capable of recording. It turns out that you were
talking about how dark the negative is.


That is the actual dynamic range of the captured image
on film, not that of the scene.

No, that's not what density is, density is a measure of how
dark the negative is. The actual dynamic range of the captured
image is from the Jones point on the exposure axis to a point
on the shoulder where highlight compression becomes obvious.
This point is never shown nowadays on H&D graphs of negative
films because it is very unlikely to be reached.


We should make it very clear too that Kodak is not
showing higher densities because the characteristic
curves do cover the range that is actually *used* when
generating photographs.

If you set your exposure meter to 400, you will not generally
have content to the right of -0.9 on the exposure axis.
(The maximum usable exposure on a 400 speed slide film would
be around -0.9)

The fact that it is possible to
get a photographically useless negative with a higher
dynamic range is not significant.

Um, it would be better to say "not normally needed or used" than
useless.


The LOG EXPOSURE range is indeed from about -2.9, to
perhaps 0 at best. None of the curves approach +0.3,
except on the chart shown on Koren's site (which and are
also for a longer processing time). But that is the
exposure range, not the dynamic range recorded by the
film.

Well the graph on Norman Koren's site has multiple curves showing
different developing times. The curve marked "8 minutes"
would correspond roughly to normal development.

The exposure range, from the Jones point to the point far
to the right where the shoulder is (never shown nowadays
on negative film because it is so far to the right) is the
dynamic range that the film can record.


There are other curves on the Kodak page, but they all
show less range than the one cited.

This is because the point on the right where the graph
cuts off is fairly arbitrary. They never show the shoulder
and the exact point where they cut off doesn't normally
matter.

It does have one interesting section:

"Well. most properly exposed, properly developed
negatives of typical subjects don't have a Dmax higher
than about 1.5 and even overexposed negatives rarely
go higher than about 2.0, so a dynamic range of 2.0
would probably take care of just about any negative
you are likely to come across. This should be well
within the capabilities of most film scanners."

That's the dynamic range needed by the scanner to scan normal
negatives. The dynamic range captured by the film is larger
than that because the overall slope of the characteristic curve
with normal negative development is around 0.6.


To be clear, that says the typical dynamic range of
properly developed negatives is between 32 and 100
or 30-40 dB. Granted that with over exposure or over
development that same film is capable of get 20-30
dB more dynamic range, but when it is used to best
effect for photography, it *doesn't*.

The output dynamic range of a negative is not relevant.
You don't look at negatives directly except when deciding
which ones to print. If you print a normal negative on 5302
print film developed to gamma of about 2.8 then you will get
a slide with the same density range as a colour reversal slide.

Which is to say, for those who want to argue that film
has more dynamic range, Tri-X and other print films are
not the direction to point. Slide film has *significantly*
higher dynamic range.

Slide film has a higher output dynamic range, but a lower
input dynamic range. The overall characteristic slope
for slide film is around 1.7. The overall characteristic
slope of negative film with normal development is around
0.6. The Goldberg criterion for viewing projected slides
requires an overall gamma of around 1.7 for the contrast
to look right.

Tri-x is a negative film. A "print film" is something like
Eastman 5302 which is used for making print transparencies.
Tri-x is capable of recording a huge range. Try doing a simple
latitude test carried over to massive overexposure. I've
done such tests and it takes a massive amount of excessive
exposure to show obvious highlight compression.

Correct negative exposure is based on the amount of shadow
detail you want to show in the final print. The headroom is
so huge that you do not normally have to worry about it.
Of course, if you really need to capture the inside of
a tire tread in the shade and bright sunlit clouds, you
are going to get a negative which is near impossible to print.

Peter.
--

Scott W wrote:
Floyd L. Davidson wrote:

They show the normal range for use in photography.
Typically a properly exposed negative is not going to
have a Dmax density higher than 2.0, never mind any 3.0
(60 dB or 1000:1).

The DMax and DMin of film does not tell you what its dynamic range are,
if fill were linear it would, but film is not.

The non-linearity is the reason optical density is the
way to determine dynamic range.

Note that with digital sensors it is measured using the
image *data*. And with film the image data is in fact
the optical density of the negative.

http://www.rangefindermag.com/magazi...ge.taf?page=50
http://www.astropix.com/PFA/SAMPLE1/SAMPLE1.HTM
http://www.scantips.com/basics14.html
http://www.dantestella.com/technical/dynamic.html
http://www.patentstorm.us/patents/57...scription.html

I'll grant that you do have at least some company with
confusing the distinction between dynamic range of the
scene and the dynamic range of the film. Roger Clark
cites the www.astropix.com URL above, and then misuses
input range for virtually all of his graphs relating to
dynamic range. He has also on at least one occasion
described totally confused descriptions of quantization
distortion as it presents in those graphs. It _is_ a
tricky subject.

You could have an input range of 10,000 fit from DMin of
0.5 to DMax of 3, for example.

You could have an input range of 100,000 fit the same
range, so the question is, what was *recorded*, the
scene range or the optical density range on the film,
which is what can be reproduced from the film.

Slide are the other way, they have a large output range
compared to their input range.

They have low latitude, but a high dynamic range.

--
Floyd L. Davidson http://www.apaflo.com/floyd_davidson
Ukpeagvik (Barrow, Alaska)

(Floyd L. Davidson) writes:

The DENSITY axis ranges from 0 to 4.0, and the curve is
plotted from about 0.3 to roughly 2.8. That is a
dynamic range of 2.5. That is what I am calculating it
with, though I was just ignoring the lower end, as if it
were 0.0, and used a range of 2.8.

That is the actual dynamic range of the captured image
on film, not that of the scene.

But when comparing methods of capturing an image, it's the *input*
dynamic range that matters. For an inherently linear device like a CCD,
the input and output dynamic range can be considered the same, but for a
nonlinear device like film or a CMOS sensor you care about the scene
dynamic range that can be captured with reasonable contrast.

The density range of the negative (the negative image dynamic range) is
of interest to the print paper, or to the scanner manufacturer -
whatever the next stage in the imaging process is. But that's not
a meaningful number when comparing the ability to capture high dynamic
range scenes.

For film, the useful dynamic range is the exposure range over which you
get a useful change in density. The meaning of "useful" is open to
debate - how much of the "toe" area should be counted?

It does have one intersting section:

"Well. most properly exposed, properly developed
negatives of typical subjects don't have a Dmax higher
than about 1.5 and even overexposed negatives rarely
go higher than about 2.0, so a dynamic range of 2.0
would probably take care of just about any negative
you are likely to come across. This should be well
within the capabilities of most film scanners."

That's talking about the dynamic range of the *film image*, which is the
input to the scanner. That's important to the scanner, but it is not
the dyanmic range of the scenes that can be captured by that film. The
latter is what's of interest when comparing to digital cameras.

Because normal B&W film has a gamma of about 0.6 (and colour film is
even lower), a 1.0 density change (10:1 transmittance change) on the
negative represents about a 1.7 log exposure change (46:1 exposure
change) in the original scene. The lower gamma in the toe (and
shoulder, if used) regions give an even larger compression of scene
range into negative density range.

However slide film is a different story. Dmax of
typical slide films can reach maybe 3.5 and Velvia is
said to be able to hit 4.0 in the deepest blacks. This
would tax even the best scanners."

Again, that's of interest to scanners. But transparency film gamma is
greater than 1.0 (and continuously changing; there's no straight line
section of the curve). So the 3.5 density range on the slide represents
*less* range in the original scene. When you take this into account,
the scene dynamic range of transparency film is considerably less than
that of negative film (and clearly less than good digital cameras).

Which is to say, for those who want to argue that film
has more dynamic range, Tri-X and other print films are
not the direction to point. Slide film has *significantly*
higher dynamic range.

The developed film image has. But it captures a smaller range from the
scene, and that's what matters here - captured scene dynamic range.

Dave

On Nov 15, 9:03 am, Bill Tuthill wrote:
Arguments over relative merits of DSLR vs P&S digicams
occupy a plurality of current traffic volume on r.p.d.

In many ways it reminds me of the film vs digital debate
of the last many years.

DSLR partisans seem like the defenders of film, because
they don't have a lot of firm evidence that their workflow
is superior, except at high ISO or some arcane usage.

I know DSLRs are selling well, but do these flame wars
indicate the beginning of the end?

I honestly don't see how there is a competition between the two types
of systems. That's like comparing a pickup truck to a sedan. Two
similar items that perform quite different tasks.

This is really simple: point and shoot cameras are designed for easy,
fast shots that don't require a tight zoom or a super-wide angle. It's
meant for convenience. Sure, there are manual settings nowadays and
even SLR-like P&S cameras, so more advanced shots are now being
produced by these little gems.

I own a Nikon D80 with an 18-70mm and 70-300mm VR (these 2 produce far
better image quality than the convenience-oriented 18-200mm VR), with
an SB-600 and a Pelican case to hold it all. I use this camera to
produce good nature shots, and decent landscape shots. I also need it
when a composed shot is difficult to pull off without using creative
manual settings.

I also own a Nikon L11 P&S camera. It's a basic P&S with little to no
manual settings. I use this camera as convenience, like when at a
gathering and I don't want to bother lugging around my gear. I just
pull it out and shoot, and the images are quite nice.


Now, as for image quality comparison, there is none. In this
department, a DSLR will win over a P&S. The ability to use excellent-
quality lenses, a larger image sensor, the option of using a speed
flash (indoor shots with a bounced flash will always look more natural
than a P&S's flash unless you get creative and use Scotch tape over
the flash), and the more advanced in-camera software and settings make
a DSLR a great option. Sure, these are all technical advantages, but
they do help when it comes to composing certain shots. When it comes
right down to it, on the other hand, it's not about the equipment but
about the eye and creativity of the photographer and I have seen shots
taken with a cheap P&S that had me thinking it was taken with a DSLR.

For convenience, there is nothing nicer than to be able to pull my L11
out of my pocket and take a quick shot with rather surprising image
results. It also records video, which no DSLR can do. There are places
that a P&S can go that a DSLR can't. It's a simple, no-hassle design.


If any of you see wild comparisons about how "a DSLR kicks the sh*t
out of all P&S cameras", just ignore it. We all know what's really
going on with today's cameras, so let the idiots just throw their
tantrums and they will tire out.

On Tue, 4 Dec 2007 13:59:16 -0800 (PST), sgtdisturbed
wrote:



If any of you see wild comparisons about how "a DSLR kicks the sh*t
out of all P&S cameras", just ignore it. We all know what's really
going on with today's cameras, so let the idiots just throw their
tantrums and they will tire out.

Except for the FACT that images have already been posted that prove you are
wrong. Comparing 2 different PS& cameras to 2 different D-SLRs. Both times the
P&S cameras won.

You'll just have to learn to accept it someday. Until you do you'll just keep
spreading your misinformation.

"William Graham" wrote in message
. ..

"Chris Malcolm" wrote in message
...
In rec.photo.digital.zlr William Graham wrote:
"TerrenceHamm" wrote in message
...

The only problem with that is unless you buy a top-of-the-line D-SLR
that
now
includes an LCD display that they try to pawn off as something special
called
"live preview", then you will only get any benefits from histograms,
under/over-exposure overlay displays, and other features,
after-the-fact.
Meaning, you can't see those features applied to anything but a shot
you
have
already taken. Whereas all P&S cameras that have those features display
them as
you are taking the photo, no time wasted taking "test shots" then
seeing
how it
turned out. You know in advance it that setting is going to work or not
before
you even press the shutter.

But the way you talk about digital Point & Shoots, one would think
they
are more sophisticated electronically, and I can't understand why this
would
be the case......Why couldn't you take a digital Point & Shoot, add a
mirror
and a rangefinder to it, and give it the ability to interchange lenses
and
have a better camera? Of course, it wouldn't be smaller or lighter or
cheaper, and therefore as capable of being smuggled into opera houses
and
night clubs, but for general photography, why wouldn't it be a better
(more
versatile) machine? IOW, why would leaving off a mirror provide the
machine
with any better electronics than not leaving off a mirror?

It doesn't necessarily provide the machine with more sophisticated
electronics, but having a mirror in front of the sensor prevents you
from using those extra sophistications, because they depend on having
the lens focussing the image on the sensor instead of through the
viewfinder. In other words, the mirror literally gets in the way.

The few very expensive DSLRs which do offer such facilities do so
either by offering a dual mode of operation, such as mirror up and
mirror down, with mirror up losing you the valued optical viewfinder,
or they compromise on optical efficiency by using a half silvered
mirror, etc.. In other words, if you want a mirror *and* those
facilities, getting round the mirror problem involves further costly
engineering and compromises.

The SLR mirror is a carry over from clockwork film camera technology
some of whose advantages haven't yet quite been duplicated by purely
digital technology. In fact digital technology can do it, just not yet
at an marketable price. We won't have to wait long. In other words
the SLR design concept is already obsolescent. There are huge
investments in the technology which will prevent it from becoming
obsolete for a long time yet, however.

OK. I understand that the mirror can be a pain. the same thing is/was true
for film cameras. but the alternative is the electronic viewfinder, and I
haven't seen any that measure up to the "real" image view that you get
with a mirror yet. These tiny screens on the back of the cameras just
won't cut it. Maybe a combination....You look in the hole just like an
optical viewfinder, but instead of a mirror, you see a huge view of an
electronic image that is as spectacular as the one you will eventually see
on your desktop 20 inch monitor.....

Which would mean an EVF resolution of more than a megapixel, maybe two
megapixels. I don't expect to see anything like that marketed for a long
time, if ever.

But apart from the difference in viewfinder clarity, the DSLR has other
advantages over anything with an EVF. My Coolpix 8800 for example is a great
camera, but doesn't have all the flash capabilities of my D80 or even D40,
or even any of the Nikon DSLRs being made when the 8800 was introduced. It
accepts the same flash units but can't do the same things with them.

For whatever reasons, the DSLR is able to do easily some things the EVF
camera cannot do at all.

Neil