Wow - read this re: Film versus Digital debate!

Oh man, isn't there some way we can empirically test this without too much equipment so we can convince ourselves?

 

:)

 

I'll have to get back to this. It's far past my bedtime here in Seattle!

 

-Rishi

"...but that such values are simulated using a controlled deposit of individual black specks."

<p>

Controlled deposit implies linearity - the controlling factor being development time. Linear process. Binary is

uncontrolled - there are only two states, and these <i>must be determined at exposure time, 4 atom threshold and

all</i> - therefore a controlled deposition process post exposure is not possible with binary grains.

Hey guys - you just all blew me away. I decided to have a look at my question and see if there were a couple more answers - I thought I was seeing things - it has blown out to over 200 responses.

 

I did not realise when I penned my humble question that I would end up with something a Post Grad student could source a thesis from - LOL

 

I am a bit confused with all the technical stuff - but to me it does not matter.

 

I love using my film cameras - to me half of it is the process, not just the finished product.

 

Ok if you are a working pro and have deadlines and customers to please. I am not anymore and don't even care if I can't get back into shooting Stock.

 

I am just enjoying puting film through my new Pentax 67 at the moment and watching those awesome trannies leap off the light-box and grab me by proverbials!!

 

Thanks heaps Greg for the link to that youtube flick - I really enjoyed that and to hear that film is still happening amongst working pro's.

 

Thanks for all the input!

 

Phil

I'll be responding to some posts, but not all because there are simply too many since I last posted. That said...

<P>Mark,</P>

<P></P>

<P><i>What I'm suggesting that the grains are photon counters and the more photos that hit the grains the more dense the filamentary structures become.</i></P>

<P></P>

<P>That the silver looks like a wool pad under an electron microscope is interesting but irrelevant. The "holes" you see at electron microscope scale are too small to attenuate light in the manner you are suggesting. A single grain is simply not discernible as being any one of thousands of shades of gray like a pixel.</P>

<P></P>

<P>If I've said it once I've said it a thousand times. Density of silver grains in a given area determines tone. This occurs on a scale viewable under an optical microscope. By 400x magnification no gray tone is visible, only black grains and clear base. For the most part this is even true at 60x. If individual grains were perceivable as any one of thousands of shades of gray like a pixel, then those shades of gray would be quite visible at 60x and 400x.</P>

<P></P>

<P>If your theory was true we would see gray grains under an optical microscope. The fact that we do not proves your theory false. (Thanks Bernie for seeing that!)</P>

<P>Ron,</P>

<P></P>

<P><i>First off, silver is not black.</i></P>

<P></P>

<P>For all intents and purposes in the context of B&W film and paper, it is. I don't know about you, but none of my B&W film looks reddish or blue. Under an optical microscope I don't even see the shades of gray that Mark insists should be there, much less shades of color.</P>

<P></P>

<P><i>Now, the electron micrograph above is developed silver!</i></P>

<P></P>

<P>The one Mark first posted? If it were developed, it wouldn't show silver bromide, but silver. It is labeled as showing silver bromide.</P>

<P></P>

<P><i>Magnification of this graphite deposit shows that it is made up of tiny dots of abraded graphite on the paper. The combination of the visual impact is either digital or analog depending on the way you view it or maybe we should say the magnification.</i></P>

<P></P>

<P>Good analogy.</P>

<P></P>

<P><i>Now an electronic D/A converter does not produce a smooth gradient, it produces a jagged gradient, but film produces a smooth gradient.</i></P>

<P></P>

<P>This analogy fails because we're talking about a visual system, not waveforms from D/A converters. Digital is known for being "smoother" in tone and appearance precisely because tone is not produced through density of a material, but is directly encoded. People call film grainy because they can just perceive the clumps of silver which create the illusion of tone. The same thing is true when trying to generate gray tones using a B&W printer (old laser or ink jet) with a lower resolution.</P>

<P></P>

<P><i>So, silver deposits in film can be shown to be having a smooth gradient with all possible tones from Dmin to Dmax, but a digital image cannot be.</i></P>

<P></P>

<P><b>At 60x individual grains become distinguishable.</b> There are no smooth gradients, there's not even gray. At 60x a digital image may show some noise, but the pixels are the colors that they are. Tone will be clearly perceptible.</P>

<P></P>

<P>Prove it to yourself. Photograph a gradient gray ramp on film and digital and print to 60 inches. You'll see which distinguishes more tones and has a smoother appearance viewed up close. If the digital image is 8-bit, you will see steps. I'm betting you won't with a modern DSLR and 14-bit processing (roughly 273 gray steps per inch if a smooth ramp were photographed and printed to 60 inches).</P>

<P></P>

<P>re: color</P>

<P><i>Now if you think this is not a problem, many small objects represented on a sensor of any type can be on the order of 1 micron.</i></P>

<P></P>

<P>Color film emulsions cannot resolve detail 1 micron wide. That would equate to 500 lpmm. Velvia, at 1000:1 contrast, resolves 160 lpmm. At normal contrast, 80 lpmm.</P>

<P></P>

<P>I quite frankly don't know why you continue to bring up aliasing since it's pretty much a none issue in modern digital photography.</P>

<P></P>

<P><i>Sorry, but unless you go into the lab and do some measurements yourself, your arguments are baseless.</i></P>

<P></P>

<P>I may have misspelled your name in one of my responses, but the statement above is rude to everyone here researching and discussing this matter. Don't assume the rest of us haven't been in a lab.</P>

<P>Ron,</P>

<P></P>

<P><i>Now, it is clear to me that these are gut arguments you all are presenting, not based on anything anyone has done in a lab.</i></P>

<P></P>

<P>I didn't come to my opinion based on emotion. I came to it precisely because I have spent time in a lab, performed measurements, and compared results.</P>

<P></P>

<P>You're basically trying to set yourself up as an authority and then appeal to yourself, a fallacy. It's not going to work. It's disrespectful to the other participants here, especially considering you have NO idea what their backgrounds may be. Further, if we are to appeal to authority, then let's just quote "The Negative" and close the thread because nobody here has produced the body of artistic or technical work which that man did.</P>

<P></P>

<P><i>Among other things, all you digital guys ignore aliasing which exists in digital but not in analog. This interests me as it shows either a lack of understanding or a wish to avoid a major problem in digital.</i></P>

<P></P>

<P>I'm ignoring it because I've never seen it in any of my own work, and therefore it is hardly a "major" problem.</P>

<P></P>

<P><i>It is plain to me that everyone in the digital arena here seems to have a closed mind to the possibility that digital is not yet perfect.</i></P>

<P></P>

<P>Nobody here has claimed digital is perfect. This has nothing to do with the thread and is basically a side rant designed to undermine everyone here who might disagree with you.</P>

<P></P>

<P><i>Best of luck to you all, but I can make 20x24 enlargements from 35mm and have proofs to show it. I cannot do that with digital and I have proofs to show it. The data was obtained using a Nikon D70 vs a Nikon 2020 with Portra 160VC. The photos were side by side comparisons. Too bad. Digital lost!</i></P>

<P></P>

<P>Now who is making the emotional argument? This isn't a "win" or "lose", this is simply an attempt to understand. BTW, I've made multiple comparison prints from various digital cameras, 35mm films, and medium format films, both through scanning and wet lab work. Which "wins" depends on many factors. In some scenarios a D70 would "win". But I'm hard pressed to think of any scenario where 35mm would "win" against a 1Ds mkII or higher.</P>

<P>Vijay,</P>

<P></P>

<P><i>Bernie, you're right - that needs clarification. I should have looked at Daniel's images more carefully.

There is a fundamental problem with those images - they progressively enlarge a binary section of the image - the

catchlights in the model's eyes. Those catchlights are completely black, the pupil is clear. The source

information is "binary", so sorry, that can't be used to "prove" that grain is binary.</i></P>

<P></P>

<P>As can clearly be seen in A and B, the image is not monochromatic or "binary". There are gray tones throughout

the region enlarged. (I've reposted so people don't have to scroll up.)</P>

<P></P>

<P><i>Halftones would require that two identical pixels, illuminated by the same amount of light (same uniform

grey wall) do two different things - (and proportional to the grayness of that wall, no less) - that's impossible

in the universe we inhabit.</P>

<P></P>

<P>Film can't magically do something that is a mathematical impossibility. You don't have to know chemistry to

understand that.</i></P>

<P></P>

<P>Grains are by no means identical in an emulsion. Size, shape, and orientation all determine the sensitivity,

or threshold, of an individual grain. Two grains next to each other can receive the same exposure, and one will

reduce to silver while the other will not. Films even incorporate multiple layers with different average grain

sizes and therefore different average sensitivities to stretch the dynamic and tonal range.</P>

<P></P>

<P>Earlier I said that I could recall an article which stated that degree of exposure had some influence over how

completely a grain reduced to silver. I've tried finding it and all I can find, in my books and in online

references, is the repeated claim that a grain is either developed completely to silver, or not. Unless someone

can produce an authoritative statement to

the contrary, I'm going on that understanding of development. I can find no reference which supports the idea

that reduction to silver for a single grain is proportional to exposure as opposed to being binary in nature,

reduced or not.</P>

<P></P>

<P>It does appear from what I've been reading, trying to refresh my memory as to the most minor details of film

development which could influence what we are discussing, that at the threshold (2-4 electrons, depending on

emulsion) a grain is not guaranteed to develop. Grain exposure above that threshold, development temperature,

agitation, and development time all influence the probability of the chain reaction occurring and the grain being

reduced to silver. This is why you can control contrast through development time. A grain in a highlight area

will have had more exposure and is likely to chain react and reduce to silver with a short time. But a grain in a

shadow area might be right at the threshold for the grain, and the odds of it reacting and reducing to silver

increase with

longer development time. But again, a grain is either reduced or not. Given the total context of exposure,

temperature, agitation, and time, it either chain reacts or not. Near thresholds you have odds of the chain

reaction occurring for a single grain, not a guarantee that every similar grain will develop.</P>

<P></P>

<P>At any rate, for all the text written in this thread, this whole debate can be reduced to a simple proposition

and test. If

a single grain can take on any tone like a pixel, then it should be easy to produce optical 400x microscope views

where individual grains are clearly seen and are clearly of various shades of gray. I've looked at many frames of

B&W film under a microscope. They all look like the example I posted. Magnify enough that the grains are clearly

visible, and it's also clearly visible that grains only come in one tone: black.</P>

<P></P>

<P>Bernie,</P>

<P></P>

<P><i>I admit, I am a bit stumped on the gray wall example. I guess it comes back to your statement about

luminance being uniform.</i></P>

<P></P>

<P>I discuss the gray wall example above, though I wouldn't expect you to try and find it now that this thread is

so long. Uniform exposure of a frame of film will not "flip" the film to white or black because grains are not

uniform. Their size, shape, and orientation varies greatly and all factors influence both sensitivity and the

probability of any single grain being reduced to silver. Given a uniform illumination exposed for middle gray,

some grains will receive sufficient exposure for their size/shape/orientation and will develop, while others will

not. Further, near the thresholds for the factors which influence development (i.e. grain exposure versus time in

developer), you have odds of a single grain developing, not a guarantee. So even with two very similar grains

with uniform

exposure at their threshold, you might have one develop while the other does not.</P>

<P></P>

<P>From above: <i>As can clearly be seen in A and B, the image is not monochromatic or "binary". There are gray tones throughout the region enlarged. (I've reposted so people don't have to scroll up.)</i></P>

<P></P>

<P>I forgot to upload it, so here it is.</P><div></div>

<P>Vijay,</P>

<P></P>

<P><i>Controlled deposit implies linearity - the controlling factor being development time. Linear process. Binary is uncontrolled - there are only two states, and these must be determined at exposure time, 4 atom threshold and all - therefore a controlled deposition process post exposure is not possible with binary grains.</i></P>

<P></P>

<P>What is linear is the probability that grains will develop as development time increases. The grains themselves either develop or not, binary.</P>

Daniel: I can find no reference which supports the idea that reduction to silver for a single grain is

proportional to exposure as opposed to being binary in nature, reduced or not.

 

Then this must imply that the reduction of the entire grain happens instantaneously, because if it happens slowly

over time, what would happen if I pulled the film out of the developer midway? Would that grain be in some

intermediate gray state? Surely that can't be - we already assumed grain is binary.

 

If the process is instantaneous, then whatever grains met whatever "threshold" (neither the grains have to be

identical, nor the thresholds, just the fact that some grains met their threshold and some didn't) would go all

black, and the others would remain all clear. Keeping the film in developer longer wouldn't help either, since

whatever is black is already fully black and can't change state; and whatever is clear is below the threshold

(ignoring the small percentage of grains "at" the threshold that could go either way) and can't change state either.

 

Then push and pull processing wouldn't be possible. Also, film would develop at first contact with the developer,

being largely independent of development time.

 

Right?

<P>Vijay,</p>

<P></P>

<P><i>Then this must imply that the reduction of the entire grain happens instantaneously, because if it happens

slowly over time, what would happen if I pulled the film out of the developer midway? Would that grain be in some

intermediate gray state? Surely that can't be - we already assumed grain is binary.</i></P>

<P></P>

<P>I have no reference which gives an estimate of the time it takes for a single grain to reduce to silver. Total

development time

is determined by and optimized for development of the full range of variable grains in a particular emulsion. The

development of any single one would have to take less time, but you are right that it can't be instantaneous.</P>

<P></P>

<P>I don't know that pulling the film from the developer would "freeze" any chain reacting grains "mid reaction",

i.e. the point where the chain reaction starts may be, for all intents and purposes, instantaneous. But if the

reaction can be slowed or stopped, you would not see a gray grain, but a smaller speck of black silver than you

should have.</P>

<P></P>

<P>I get your point though, and it would imply that, in fact, development time does influence how completely a

grain is

converted to silver, contrary to my assumption above and to the texts I'm referring to. That is if the reaction,

once started, can be stopped midway and occurs on a timescale where this means something in practical use.</P>

<P></P>

<P>I'm going to keep looking for the reference that implies as much, and I'll gladly correct my above posts if I

find it. But...and this is important...grains would still be black specks with tonality determined at a level

observable under an optical microscope. If only half of a silver halide crystal were converted to silver because

of short development time, you wouldn't have a gray grain, you would have a smaller black speck. This would be

similar to an ink jet printer which can not only vary the pattern of dots, but the dot sizes. It still would not

be like a pixel which, again, can be any tone.</P>

<P></P>

<P>I keep bringing that up not to prove that digital "wins" anything, simply to note that grains are not like

pixels, and therefore conclusions about resolution, tonality, etc. cannot be made by comparing pixels and grains

1-to-1.</P>

<P></P>

<P><i>If the process is instantaneous, then whatever grains met whatever "threshold" (neither the grains have to

be identical, nor the thresholds, just the fact that some grains met their threshold and some didn't) would go

all black, and the others would remain all clear. Keeping the film in developer longer wouldn't help either,

since whatever is black is already fully black and can't change state; and whatever is clear is below the

threshold (ignoring the small percentage of grains "at" the threshold that could go either way) and can't change

state either.</i></P>

<P></P>

<P>But thresholds are not hard and fast points. That's something that really

stood out at me reviewing a few different texts before posting this morning. A simple illustration: at 2 minutes

maybe half of the

crystals near their threshold develop, while 3/4ths that got more exposure develop. At 4 minutes maybe 3/4ths near

their threshold develop, while all the ones with more exposure develop. At some sufficiently long time, every

crystal on the film will be reduced to silver including those never exposed.</P>

<P>Vijay,</P>

<P></P>

<P>I feel silly for missing it, but the article has been referenced 3x in this thread though different sections

were quoted.</P>

<P></P>

<P>http://www.cheresources.com/photochem.shtml</P>

<P></P>

<P>Relevant text:</P>

<P></P>

<P><i>When an exposed film is placed in a developer solution, the grains that contain silver nuclei are reduced

much faster than those that do not. The more nuclei present in a given grain (i.e., the greater the exposure of

that grain), the faster the reaction with developer and the darker the image at that site in the film. Factors

such as temperature, concentration of the developer, pH, and the total number of nuclei in each grain determine

the extent of development and the intensity of free silver (blackness) deposited in the film emulsion in a given

time.</i></P>

<P></P>

<P>Note: by darker I do not believe they are implying that a grain can vary from light grays to black, which we

simply do not see in microscope views. Darkness is explained by the text "...intensity of free silver (blackness)

deposited..." The site on the film appears darker at a distance because more silver or "blackness"

is there, i.e. a larger black speck. Again, tonality is formed at a level observable under a microscope by grains

which are black but vary in density which, as we see from this text, includes number and size.</P>

<P></P>

<P>Also:</P>

<P></P>

<P><i>The rate of development, as determined from the change in the optical density of the developed image, is

complicated by the fact that density increases in two different ways: (1) by the increase in the amount of silver

as the grains develop and (2) by an increase in the number of grains in the process of development. Density grows

rapidly at first and then slows down until development is complete and no further growth in density takes place.

Prolonged development would, of course, increase overall density through the development of unexposed grains

(fog).</i></P>

<P></P>

<P>So grains with high exposure start to develop sooner and develop more quickly to silver, while grains with low

exposure take longer to start developing and then develop more slowly into silver. Good call on your last post.

You made me keep looking.</P>

<P></P>

<P>Where are we at in regard to Reichmann's article? I still say from the perspective he was looking at things,

his article was fairly accurate. His whole point was that an individual grain is not like a pixel, able to assume

any tone. You need a cluster of grains to form a tone. That's true. And in one sense grains are "binary" because,

individually, they are one tone. But in another sense they aren't because they can vary in final size due to

exposure/development, which influences the tone perceived at lower magnification.</P>

<p></p>

<p></p>

Been said before, but I'll add mine 2cents.

 

I shoot both. Commercial and corporate is done on 40D and 1Ds, and my choice landscapes are on MF and 35mm film. My 1Ds walks all over 35mm in resolution, but cannot compete with the look and DR of film. Which is the real issue, it's the look I want. For many of my shoots I always carry the 40D. I will experiment with that, get instant gratication, and then follow up the selects with film. Yes, digital is much cleaner as the SNR is better, but many times it's the imperfections or shortcomings of film that I want to be part of the image in the first place.

 

I think we need to stop arguing about digital vs. film. It's really neither. They are formats and have looks in their own right. Film and film gear is cheap when you consider Ebay and processing at $6 a roll for MF, compared to $7K for a new 21MP camera kit.

 

The real value of digital is in the development and print technology. No more dark room. A good scanner and pigment inkjet far offsets the real cost/labor of film.

 

After working with both and balancing the merits, I had to say no contest. Just shoot.<div></div>

Here is the same scene with Film:<div></div>

DLT:

 

That the silver looks like a wool pad under an electron microscope is interesting but irrelevant. The "holes" you see at

electron microscope scale are too small to attenuate light in the manner you are suggesting. A single grain is simply not

discernible as being any one of thousands of shades of gray like

 

So those holes are too small to let light through? how can that be?

 

I'm NOT suggesting that a single grain is many shades of grey far from it, what I am suggesting is that the filamentary

structure of grain is proportional in density to the light that strikes it.

Many grains stacked though several layers, overlapping or not, all attenuating light proportional to the silver content

create the ILLUSION of tone, just as clumping is an OPTICAL effect, not a physical on, graininess is also OPTICAL.

 

DLT:

 

If your theory was true we would see gray grains under an optical microscope. The fact that we do not proves your

theory false.

Quite the opposite just because we see black specks under a microscope doesn't mean the are SOLID and OPAQUE.

Just remember that those grains are filamentary and pass light (as you've conceded) just because a lower magnification

make those LOOK like solid lumps doesn't mean they ARE.

The magnification doesn't change the property of the filamentary grain it still has holes you just can SEE them.

 

Look, you still haven't explained the image that shows a black grain with a hole in the middle if film is binary it must be

opaque 1 (solid) or not 0 (clear) it cannot be the both at the same time!!!

DLT

Where are we at in regard to Reichmann's article? I still say from the perspective he was looking at things, his article

was fairly accurate. His whole point was that an individual grain is not like a pixel, able to assume any tone. You need a

cluster of grains to form a tone. That's true. And in one sense grains are "binary" because, individually, they are one

tone. But in another sense they aren't because they can vary in final size due to exposure/development, which

influences the tone perceived at lower magnification

 

Hey Daniel that is my position and what I state in my blog (if you bothered to read it)

 

Reichmann actually stated:

"An individual film grain can only be either black or not-black, on or off, exposed or not exposed"

 

We know that that is untrue because when he states black he means OPAQUE for it to be binary it must be black or

clear.

We know that it is untrue because the grains are a structure that lets light through in VARYING amounts that when in a

stack give the ILLUSION of tone but because the amount of light they pass is variable the cant be binary.

 

For a binary state to exist they would have to black light TOTALLY (1) or let it through (0) but we already know their

property is to transmit light in proportion to exposure.

 

m

Daniel - also its not like you have one sensitivity speck on a grain - you have many, which means that a single grain will seem to be made of several areas of "black" silver spots and several clear areas - sort of like a halftone shading of the grain itself. Like I said before, nobody denies that the state of metallic silver can either be present or absent - i.e, one of two states at the end, but the grain itself is not a binary entity. It doesn't transition rapidly from state to state, and it can and does have intermediate, continuous, stable values of silver in it, proportional to exposure.

 

Precisely a linear system.

 

As for resolution, if a grain can have continuous values, then why - the largest of these grains would determine the smallest resolvable feature size, not a clump of 40-60 grains; which occupy such large area that it would yield too low a resolution number for film. I am also aware that grains don't line up precisely in rows, so it may take 2-5 median grain widths to resolve the thinnest line, not the one grain I've been saying for the sake of argument. But Reichmann takes the approach that a 10 micron grain is entirely black or entirely clear - that would give single digit resolution numbers; and that is not borne out by practical experience.

And let me illustrate how apparent grain much larger than each individual grain crystal can occur if this grain crystal has "halftone shading".

 

Please see the attached picture. I made a quick and dirty halftone grain (top right corner), and randomly "brushed" this at different places. More in some places, less in others (sort of like an image). See how big grainy things appear to form in places - this is the graininess you see at lower magnifications, not the actual grain.<div></div>

Daniel;

 

Any electron micrograph can show both developed silver and silver halide if the process is interrupted at a given

time. This is often done by quenching and then preparing a carbon replica of the silver halide crystal.

 

Also, any process can be shown to be "digital" at the molecular or atomic level. A solution of dye has a given

density, and repeated dilutions can give an infinite level of densities. The difference is that mankind has only learned

how to do this in rather large steps called bits, and usually not much more than 64 bits in some series of steps or

about at the micron level, whereas in nature the steps represent the angstrom level in atoms and molecules.

Therefore, in that dye solution, a single molecule of dye represents one bit and each bit has an epsilon value (molar

absorbance) associated with it which represents 6.023 x 10^23 "bits" possible in a molar solution of dye. That is

pretty huge compared to digital and is what is going on in color film and B&W film. Chips cannot achieve that

resoluton.

 

Now, as for calling myself an expert, I think that being a system engineer at Kodak directly working on this type of

problem in R&D for 32 years kinda qualifies me as at least knowing what I'm doing and talking about. I'm tired of

hearing this pseudo scientific argument about analog being digital. It is incorrect except at the atomic level. You

either expose enough silver halide molecules to form a latent image or not! You may have more than one site on a

grain though and some may be exposed and some not. The grain does not have to develop completely. Therefore it

is not on/off, it is any posssible condition from on to off. A digital camera is on/off and that is an absolute.

 

Oh, and the pictures from the D70 and the 2020 are quite striking when you look into the dark areas at high

magnification. You see streaking and noise in the digital image which is inherent digital at the present level of

technnology. You don't have to be an expert.

 

Ron Mowrey

Vijay, you misinterpreted Ansel Adams in your analysis. Let me quote the FULL QUOTE:

<p>

"Examination of a photographic negative with a magnifier reveals that it is not made up of a continuous range of white-to-black values, but that such values are simulated using a controlled deposit of individual black specks. These specks are the grain of the emulsion, the reduced metallic silver deposited when a halide crystal responded to light and 'developed'." Page 19, <i>The Negative</i>

<p>

He says: 'controlled deposit of individual black specks'. I repeat: individual black specks. I.e. either black specks exist on a spot of film, or they don't. How can you get any more binary than that?

<p>

Moreover, in the next sentence, he says 'these specks are the grain'.

<p>

The 'controlled deposit' is 'controlled' by how many photons hit a given area of film. Some grains within this area do not experience enough productive collisions with photons to result in 3-4 reduced silver atoms at a sensitivity site. Some grains do. Those that do are further reduced upon development (whether or not this process is 'analog'... i.e. based on the number of metallic silver atoms at sensitivity sites, the rate of reduction of all AgBr salts within the crystal is controlled... is what we are trying to figure out in this gargantuan debate. This is why I was asking you to please read the chemistry of the process) to:

<p>

<ul>

<li>a.) either a fully black metallic silver grain (with all AgBr salts reduced to metallic Ag), or</li>

<li>b.) a grain containing black metallic silver atoms in proportion to the initial exposure of *that very* grain.</li>

</ul>

<p>

Thus, in the end, the amount deposited is 'controlled' by how many of the Ag crystals, within a given area of film, develop to black, and how many are dissolved away in the development processed. This, in turn, is 'controlled' by how many photons productively hit this site of the film, which, in turn, is controlled by the brightness/darkness of whatever is being images at this point of the film.

<p>

"therefore a controlled deposition process post exposure is not possible with binary grains." -- <i>Nope, you have not proved this with your argument, because I just showed how it is possible above. I'm not saying I'm right & this is the only way it works, I'm just saying that it is certainly possible, and I insist that you desist from proving this well established theory wrong UNLESS you can show me that light uniformly falls on all silver crystals within a given area and the sensitivity of all these crystals within this area is EXACTLY THE SAME therefore one crystal can't respond differently than another and, for example, NOT reach the threshold of 3 reduced atoms while the silver crystal next to it DOES reach the threshold of 3 reduced silver atoms.</i>

You think "Those that do are further reduced upon development to: b.) a grain containing black metallic silver atoms in proportion to the initial exposure of *that very* grain." describes a binary grain?

Ron Mowrey - I just figured out that you were talking about resolution as quantization steps of a single pixel (that is the correct terminology too); we were talking about optical resolution - as in MTF of film kind of resolution. I see how your posts address the former, not sure how they address the latter.

I carefully read every single post, and considered all of the arguments. As a result, I lost my job, my wife has left me, and my car just broke down. Oh, and I still can't make heads or tails out of this thread.