Wow - read this re: Film versus Digital debate!

[rishij]

Vijay:<i>"So a clear area of processed film can't have any speck of silver anywhere in the Z dimension now, can it?"</i>

<p>

<b>YES IT CAN.</b>

<p>

(This message is approved by Obama for America)

[vijay_nebhrajani]

Rishi: "YES IT CAN."

 

Because... we believe in change?

[rishij]

How can you so surely say that a clear area can't have any speck of silver anywhere, the X-Y or Z dimensions? Is

Dmin always 100% transparent?? If there were 1 silver speck in a 1cmx1cm area, would that really affect your

perception of Dmin?

 

Tonal range can be enhanced by layers precisely because stacking grains (or should we be talking about 'silver

deposits/specks' or 'filamentous growths'?) increases Dmax. By attenuating more light than one silver speck at

any given Z-axis coordinate would. Sure I'm not saying that the grains have to be stacked *exactly* on top of one

another so that they perfectly line up (a near impossibility given the heterogeneity of grains), but even if you

have two resulting silver specks, on two layers, half overlapping, you'll get more light attenuation. Having

layers can also help increase the density of specks for any given area beyond the achievable density by the

growth of such silver deposits on one layer.

 

I don't know how I could make this any more clear. Somebody else explain this for me. I don't understand why this

is so difficult for Vijay to understand. My point in saying that silver specks are not black holes is simply to

hammer my point home that I'm not so presumptuous to say a cluster of silver speck blocks 100% of the light

shining on it. Remember there are inter-grain gaps (gelatin) as well as inter-speck gaps (sub-granular, or across

the distance of several or more grains) due to decreased photon exposure of sensitivity sites. You increase the

chances that an area corresponding to said speck(s) will block light if you increase the density of silver specks

in that area, either in the X-Y, or Z dimension.

 

Furthermore, I don't even know the answer to this, but: if you just had one layer of B&W film, 100% exposed,

developed, and then you held it up to the light, would be 100% opaque? What if you held it up to the sun? 100%

opaque still? I doubt it. Because if I take a completely unexposed portion of Velvia, yeah it looks black, but

hold it up to a bright enough light source, and some light leaks through. Stack two layers of black Velvia film

on top of one another, now I can hardly see anything even with a very bright light source. Yes this is an extreme

example but it serves to prove my point.

 

Rishi

 

P.S. Rich: that's an awesome shot of your car with the fall colors!

[rishij]

VIjay: <i>"Now when you want to print that image, that very same speck of silver that was not completely opaque would absorb some of the enlargers light, contributing to tone. It wouldn't matter whether this speck is visible even at "human perceivable magnifications" (not sure about that, but I'll assume through an optical microscope) - but as long as it absorbed some of the enlargers light it contributed to tone."</i>

<p>

<b>No one's disagreeing with you here!</b> Sure it 'contributes' to tone. Just like one tiny silver atom, technically, contributes to tone. Not much, but it still does. This argument doesn't at all disprove the halftone process.

<p>

Quit arguing with yourself Vijay. We're all arguing the same thing at this point.

[bernardwest]

<i>Don't confuse all this with me making a hypothesis that grains are gray<p>

 

The direction that scientific enquiry takes is that you make a hypothesis first, then you attempt to refine or reject <b>based on observable data </b></i><p>

 

So what refinements have YOU made based on the <b>observable data</b> the seems to suggest you are wrong?

[rishij]

James: <i>"I'm hanging in there in the hope that they can actually prove that film is binary. That will lay to rest forever the film vs. digital debates since it will be proved to be all the same anyway.</i>

<p>

No, proving film grain is binary (which we haven't really done and none of us even intends to do at this point) would make film vastly inferior to equivalent sized digital sensors. Luckily, it's more complicated than that.

<p>

Rishi

[rishij]

Vijay:<i>"Oh and Rishi, don't forget to do a similar analysis for chromogenic (C41) B&W. This is presumably made

of dye clouds a bit larger than grains in conventional silver halide film. Say 5 microns x 5 microns at most for

a dye cloud. But there is an important difference - a single dye cloud can represent all 64K tones or maybe even

more, so is effectively a complete pixel. So chromogenic film must be able to resolve like 100 lpmm, or like ten

times the resolution of conventional silver halide!

<p>

Right?"</i>

<p>

No, not like ten times the resolution of conventional silver halide. Have you so soon forgotten that we've been

arguing that it is silver deposits growing from sensitivity centers, subgranular in size, that are the imaging

elements? Their size/density determines the tone of a given area?

<p>

And what's so surprising about your chromogenic film analysis? Sure let's say dye clouds are 5 microns x 5

microns, and can actually represent that many tones. For 35mm film, 36,000 microns (width) divided by 5 microns

gives you 7200. 24,000 microns (height) divided by 5 microns gives you 4800. 7200x4800 = 35MP. But say you're off

by a little bit... like say the region of film that actually gives you 16,000 tones (or what have you) is 7

microns x 7 microns. Do the calculation... you get 17MP.

<p>

All sound reasonable to me. Correct me if I'm wrong.

<p>

Rishi

<p>

P.S. Vijay, now do you finally admit that tone & resolution, when doing a comparison of real-world resolution of

film vs. digital (and not simply 'resolving power), are intimately related? I love how people on this thread

don't admit it when they're wrong. I'm not afraid to admit that my understanding of 'grain' and just what is

'binary' (or not, as it were), has changed significantly throughout this thread, as I've been engaging in that

incredible process known as <b>learning</b>.

[bernardwest]

<I>pigment particles are in the order of 100 nanometers, perhaps invisible at "human perceivable magnifications" but they form tone just fine.</i><P>

 

Sorry, I haven't read your PDF as my internet connection has been throttled for the next week or so. But I would like to hear you explain how it is 1 pigment that isn't perceptible can contribute to tonal resolution (which I remind you is a VISUAL phenomenon). Seriously Vijay, once again, your head is in the wrong frame of reference.

[kelly_flanigan1]

In some industries like repro work film disappeared a decade ago.<BR><BR> Thus the "Film versus digital" debate is like arguing over 286's, space food sticks, microwave versus regular ovens; whether color TV will stay; whether HiFi stay; whether folks will accept radial tires; gasoline above 90 cents; whether the Dodgers will succeed leaving Brooklyn.<BR><BR> Film died off in repro work starting in the late 1980's early 1990's. We got DOS scanners with fast 25Mhz 386's with a printer that cost 55 grand; one scanned drawings at 400dpi 36 inches wide before Photoshop was born. <BR><BR>Demand for film dropped; players exited the field; prices rose. <BR><BR>In the typical "three supplier" gambit after there were only two players rose radically; then it was one and it went nuts. <BR><BR>One would radically use the old process camera less as "digital took hold" in the later 1980's early 1990's. One would dump more chemicals than use them. Hazard fees got tacked on with chemical shipments.<BR><BR> 600 buck rolls of film 36" wide by 100 foot long got interesting to mice; they would chew a hole and the roll would get exposed for many feet; the ends ruined. Costs skyrocketed; less of us used process cameras; eventually all folks pulled the plugs.<BR><BR> If you think that film in all sizes will be made forever dream on. If in makes no economic sense it will be axed; like decades worth of formats and film have thru the ages.<BR><BR>

[nigel meaby]

I'm calling a "Time- Out" and providing a link to some recent work by a Professional Photographer (Magnum member) that looks none too shoddy shot on 35mm film!! He probably shot the whole project while you "binary bores" have been going round in circles chasing each others' tails!

http://insight.magnumphotos.com/essay/foreclosures

[desmond_kidman]

Wow, has this thread gone on!

 

I'm curious: with such passion, it is obvious that this is an important subject to folks. Lots of theory, but true scientists who put forth theory are driven to test the theory. So I am curious: how many folks who have posted actually taken a state of the art digital camera with one of the finest lenses available, taken a shot, and gotten a high quality print made, and compared it to the same shot with a top end film camera, similarly good lens as on the digital camera, and taken this to a print?

 

The above is not hard to do, really, and is not very expensive if one rents.

 

After the above experiment one can then test, under practical conditions, whether the theory pans out, and under REAL WORLD conditions what results in the most pleasing print.

 

Picking up information from another site running tests, or talking to "a friend who is a pro and says xxxx xx", or "an agency says....xxx xxx" are all completely anecdotal.

 

I'm impressed how many folks have extremely strong opinions on either side, so I'm very curious how many have done the test for themselves.

[don_e]

"I suspect anyone seriously undertaking this task would uncover a typically sordid fable of corporate greed, cynicism, clever manipulation of the market, the generation of "artificial demand," and so on."

 

Well...yes and no. Back in the mid-1980s slr sales began to decline. That decline continued until digital cameras hit the market. Japan's electronic industry's product cycle control is legendary. We studied it a lot in the late 80s during the Great Perestroika of American industry. Their ability to get a new product on the shelves, while extinguishing existing inventory, while gearing up to manufacture the next product, while R&D the next to the next product was and is admirable...this is the so-called pace of innovation or rapid technological development: in fact it is really a finely honed product cycle control.

 

Various media, magazines, websites, television etc etc love this sort of thing because it is new and exciting. There's a story to tell and a positive feel good one because everything is improving, getting better, faster, bigger, smaller; there's something to write about, something to tout, to be first, to be right, to be on the cutting edge. Careers are made out of it. Status, coolness -- we're all monkeys, so no blame.

 

But understand this: not many people were buying film slrs any more. What was Japan, Inc's alternative with film? To cheapen the product so that in broke in 3 years and could not be repaired so photographers would have to buy a new one? Change lens mounts every 18 months? It was a dead end. Digital saved them.

 

This has nothing at all to do with the comparative quality of film or digital. It's just business.

[kelly_flanigan1]

Labs die off too. Here I got a 35Megapixel scan back; then a 50 megapixel scan back too to shoot artwork. One got great scans with no farting around whetehr the senile old lab would loose or botch 4x5 trany films. Part of the movement to digital is folks have deadlines; amateurs dont. They shoot for fun. Real clients often want digital proofs; digital scans of product advertising on a timely basis; thus scan backs suchs as the ones I got a decade ago have long been used for studio work. In some industries film was abandoned over a decade ago; NOT for anything mentioned in this thread; BUT deadlines. Thus alof of film is thus used by old farts who dink around shooting fine art stuff with no deadlines. In newspaper work digital was used even 15 years ago. In LA realtors used digital on BBS's for houses when a high end camera was 320x240; and a pros a VGA unit costing several grand.

[desmond_kidman]

"Status, coolness -- we're all monkeys, so no blame."

 

Not so for me....I could not care less what is "cool", "fashionable", or new. Even one of my businesses, making turntables to play vinyl records, started after digital music came out and everyone said I was crazy to do what I was doing. And I suspect a lot of photographers are like me and simply want to create images. Most truly creative people, I think, march to their own drummer and don't care what's fashionable. But I have used some key phrases, I think, in folks who "simply want to create images", and "truly creative people". I'm not talking about gear junkies....they most certainly are monkeys and wish to impress themselves and othes.

 

This has nothing at all to do with the comparative quality of film or digital. It's just business."

 

Again, I disagree, for reasons stated above. There are folks making choices based on their own sensibilities, one of which include comparative quality.

[nigel meaby]

Lets not delude ourselves here. Our Capitalist society would grind to a halt if we were'nt seduced into thinking we must have the latest technology. Oh, hang on a minute the world economy is grinding to a halt!!

[vijay_nebhrajani]

Rishi - do you even understand what it means to have 2^16 tones? It means that the brightest area is 2^16 times

brighter than the darkest area. If you want opaque silver specks, then no matter how many or how few specks or

how many specks make up the opaque area, the transparent, or clear area must be 1/65,536 of the opaque area. Form

the opaque area with overlapping specks, non-overlapping specks, black holes, whatever, but leave an area

1/65,536 of the opaque area clear. If your smallest clear area is at least 200 nm because as Daniel postulated, a

smaller hole than that wouldn't even pass light through then the opaque area must be 65,636 x 200 nm x 200 nm -

which would result in exactly my calculations.

 

Again, regardless of how the opaque area is formed, you need a clear area of 200 nm x 200 nm and a dark area

65,536 times larger. How the clear area is formed (one single huge silver speck, a billion overlapping ones) is

immaterial. Its area matters.

 

If you couldn't successfully do that, you couldn't create 65,536 tones. End of story.

 

Rishi: "Tonal range can be enhanced by layers precisely because stacking grains (or should we be talking about

'silver deposits/specks' or 'filamentous growths'?) increases Dmax. By attenuating more light than one silver

speck at any given Z-axis coordinate would."

 

Damn, man, it sounds like you don't understand the meaning of the word opaque. You can't stack opaque grains on

top of each other and expect density to increase. A coin is opaque. Stacking ten coins on top of each other

results in a structure that is also opaque.

 

A neutral density filter is not opaque. Stacking two neutral density filters attenuates more light.

 

You could stack if you had non-opaque specks of silver (like ND filters). You couldn't stack opaque silver specks

(like coins).

 

So you must be saying that the silver specks (even though Daniel, Reichmann and Adams always see them as opaque,

like a coin) must be transmissive (like a ND filter)? That means you must be agreeing with (gasp) me, Mark and

Ron Mowrey even though you don't seem to realize it.

[vijay_nebhrajani]

I said: "How the <i>clear</i> area is formed (one single huge silver speck, a billion overlapping ones) is immaterial. Its area matters."

<p>

Correction: This should read: "How the <b>opaque</b> area is formed (one single huge silver speck, a billion overlapping ones) is immaterial. Its area matters. "

[vijay_nebhrajani]

Bernie: "But I would like to hear you explain how it is 1 pigment that isn't perceptible can contribute to tonal resolution (which I remind you is a VISUAL phenomenon). Seriously Vijay, once again, your head is in the wrong frame of reference."

 

Man, again?

 

One pigment particle is not perceptible at what you call "human perceptible magnification", because it is too small to be seen through an optical microscope.

 

Yet, you wear light pink and dark pink shirts - that is your tone, your visual phenomenon, and that was achieved by using that very same pigment the individual particles of which were not perceptible at "human perceptible magnification".

 

Similarly, there could specks of silver, much too small to be perceptible at "human perceptible magnification" (i.e., not observed by Daniel, or Reichmann, or Adams) that contribute to the tone or the visual phenomenon.

 

Daniel categorically said that this can't possibly happen.

 

I'm refuting that.

[jstarks]

I've used point and shoot film cameras and recently (2006) bought an Olympus E-300. I enjoy using a digital

camera, and have found a workflow that doesn't involve hours of post processing. As mentioned previously create

images using the medium of choice and if you're good the results will speak for themselves.

 

Jesse

[rishij]

Vijay,

 

Just how dense are you? How many posts have I admitted that the real explanation is something in between the 'binary' camp and the Mark/Ron camp (I don't add you to that list because all you seem to be doing lately is trying to lash out at everyone... even when the AGREE with you... did you not read when I wrote: "No one's disagreeing with you here! Sure it 'contributes' to tone."?).

 

As for your 'do you understand what 2^16 tones means'? 'Do you know what opaque is?' 'Do you understand binary?' Yeah, clearly I can take part in and understand this incredibly convoluted debate, but I don't know how to add 2+2. That's likely. You, on the other hand, can't even understand when people agree with you when they say 'no one's disagreeing with you here!'

 

You say: "You can't stack opaque grains on top of each other and expect density to increase. A coin is opaque."

 

YES YOU CAN. And what's up with the coin? It's a macroscopic object. We're talking on a molecular level here. Anyway, back to the film. When you stack three layers of grains, the grains don't perfectly match up, and neither do their sensitivity centers. So what are you effectively doing? You're increasing the total number of sensitivity centers per unit area that photons can hit. So therefore you're increasing the density of light-sensitive elements in the film. So therefore you're increasing the tonal range possible for every given unit area of film.

 

First of all, I don't really believe that film can resolve 2^16 tones. I've read estimates around 2^14 tones, or ~16,000. With three layers, assuming that the majority of sensitivity centers presented by all three layers of grains do not overlap considerably (a reasonable assumption given how small sensitivity centers are), you can effectively divide that number of tones by 2, and you get ~5,000 tones per smallest resolving area per layer. If 35mm film has a resolution of ~20MP, that means 500 grains per layer must represent 5,000 tones. That requires that 1 grain, on average, be able to represent 10 tones. Just 10 tones. Which is more than reasonable given the hundreds of sensitivity centers 1 grain may have.

 

So what the heck are you arguing about Vijay? Who says that ONE layer of fully exposed B&W film is completely opaque to a bright lightbox shining white light behind it? What if the inter-grain spacing is not enough to block all the light coming through? I never said that a gap smaller than the wavelength of light blocks all incoming light -- if it did that, you wouldn't get diffraction patterns in the double slit experiment! In this case, additional layers will help in blocking all the light, because inter-grain areas would most likely *not* line up between layers, allowing one to achieve more density... and this doesn't even take into account the gaps that are formed between filamentous growths because not all sensitivity centers are equally sensitive to light due to placement, geometry, and grain heterogeneity.

 

Somebody else please step in here. I feel like I'm arguing with a highly reflective wall, that just tries to spit back problems with my points without actually critically thinking and coming up with a reasonable theory itself.

 

Rishi

[rishij]

BTW, I said : "If 35mm film has a resolution of ~20MP, that means 500 grains per layer must represent 5,000 tones. "

 

Here's how I got that:

 

Take on average that each grain is 1 micron x 1 micron (an overestimate, probably). Multiply that by 24,000 microns for the height of film, and 36,000 microns for the width of film. You get: 24,000x36,000 grains. Or 864,000,000 grains... which I round of to 10^9 grains.

 

If film has a resolution of ~20MP, then, 10^9/20x10^6 = an area of 500 grains per 'pixel'.

 

Hence an area of 500 grains must represent 2^14 tones. Don't forget to take into account the extra layers of grains.

 

I'm done here, I need to go make myself useful.

Rishi

[vijay_nebhrajani]

Rishi: "Who says that ONE layer of fully exposed B&W film is completely opaque to a bright lightbox shining white

light behind it?"

 

Daniel. He said that even one speck of silver is completely opaque to a bright lightbox shining white light

behind it - and even showed microscope images to "prove" it.

 

Rishi: "What if the inter-grain spacing is not enough to block all the light coming through?"

 

Daniel said that if the inter-grain spacing is near the wavelength of visible light (0.4 microns), it will block

ALL light coming through, like a Faraday cage (the screen with holes in the front of a microwave oven) blocks

microwaves. Maybe he doesn't know about the double slit experiment.

 

May I remind you, I am saying none of these things. These are what Daniel said. I am refuting him, which means I

am saying that the OPPOSITE is true.

 

I'm doing that by

 

a. Assuming what Daniel says is true.

 

b. Deriving conclusions based on this.

 

c. Showing that the conclusions are absurd. Proof - your annoyance at me.

 

d. Implying that if the conclusions © are false, then the original premise (a) is also false.

 

Thus, I am refuting Daniel.

 

If you agree with Daniel, I'm refuting you too. Otherwise, you are agreeing with me (and Mark Smith, and Ron

Mowrey).

 

In that case Daniel, Reichmann and Adams must be wrong (the arguments are mutually exclusive).

 

Rishi: did you not read when I wrote: "No one's disagreeing with you here! Sure it 'contributes' to tone."?

 

Sorry, my reply was to your post previous to that.

 

And Daniel IS disagreeing with me about these points.

 

If you

agree with me and understand what I am saying, could you make it clear to Daniel please - that silver specks can

have states between opaque and transparent, and a say 50% transmissive speck, even if it were too small to be

seen at 400x under an optical microscope would contribute to tone in the final print.

 

Because Daniel categorically said, again and again, that such is NOT the case.

[vijay_nebhrajani]

Here's Daniel's last post to show what he said.

<p>

Daniel Lee Taylor , Nov 15, 2008; 03:42 a.m.

<p>

<i>Will silver deposits too tiny to be resolved with an optical microscope still be capable of attenuating

(reduce the intensity of) light passing through?</i>

<p>

If they're too small to be observed under an optical microscope, they're too small to make any difference in the

perception of detail or tone in a final print at much lower magnifications. So it might be an interesting

question for a physicist (how does matter interact with light at the size threshold, whatever it is for a given

material, between transparent and opaque), and I would even be curious as to the answer. But it doesn't matter as

far as this thread is concerned.

[rishij]

I DO NOT agree with you that you can have a 50% transmissive 'speck' or 'filamentous growth'. It's a halftone

process! Do you at least agree it's a halftone process that generates macroscopic tone?? The filamentous growths

are, for all practical purposes, opaque. But their local density determines whether or not light makes it through

some arbitrary area, when viewed macroscopically at low magnification. Therefore, an area of a bunch of

filamentous growths can still appear *not entirely black*, until the filamentous growths from successive layers

stack and make it dense enough to appear black. This is how you increase tonality.

 

Look, say one layer of film could go from clear to completely black. You'd have a limited number of tones

representable. Let's say X number of tones. Now, let's say you modify the process such that, with the same number

of grains per layer, one layer can only reach ~50% black (which you can do by making grains heterogenous enough,

thereby presenting vastly different sensitivity centers.). Now you have another layer stacked on top to help

reach 100% black. Now, you've effectively doubled the number of tones representable by the media, while keeping

the dynamic range the same.

 

Get it?

 

I think the underlying problem in all our disagreement stems from your understanding that 75% light will expose

all sensitivity centers 75%. That DOES not happen, due to heterogeneity of grains/locations of sensitivity

centers. Therefore some sensitivity centers develop and some don't. This is what gives rise to tone.

 

At this point, it's like I don't disagree with you & I don't disagree with Daniel, and I just don't have the time

right now to explain again and again how this can be possible. I do disagree, though, that absolutely *no* light

makes it past 200-400nm gaps. *Most* light probably doesn't, but now we're just arguing things that can't be

verifiable without extensive research/experimentation. Which I'd love to do. Just can't, right now at least.

 

Rishi

[vijay_nebhrajani]

<b>Rishi Sanyal , Nov 15, 2008; 07:03 p.m.</b>

<p>

<i>The filamentous growths are, for all practical purposes, opaque. But their local density determines whether or

not light makes it through some arbitrary area, when viewed macroscopically at low magnification. Therefore, an

area of a bunch of filamentous growths can still appear *not entirely black*, until the filamentous growths from

successive layers stack and make it dense enough to appear black. This is how you increase tonality.</i>

<p>

<b>Mark Smith , Nov 06, 2008; 07:04 a.m.</b>

<p>

<i>Those black specks when looked at closely (50,000 times mag) are filamentary like a wire wool pad, the density

of that pad is dependent on how many photons strike the grain, and the grains are stacked so density varies

normally between 0.10 - 3 density. Mark</i>

<p>

You, at this point are saying EXACTLY what Kodak, Ron Mowrey, Mark Smith and I have been saying all along.

<p>

And EXACTLY the opposite of what Daniel Lee Taylor has been saying all along. I don't even know what Bernie West

has been saying (other than arguing against me.)

<p>

So do you finally admit that Reichmann is wrong then?