russianRF
Fed 5C User
Do you have any evidence besides your own claim that you can refer us to, Pherdinand?
Film Scanning - Optimum resolutions for different film types?
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Pherdinand
the snow must go on
well, don't know. Exactly how many and what kind of references would you like me to quote, if the book i suggested was not enough? Or do you think a random internet site would be more believable?
OK here's wikipedia, what it says further:
"Granularity is a numerical quantification of film grain, equal to the root-mean-square (rms) fluctuations in optical density, measured with a...bla bla."
Fluctuations in OPTICAL DENSITY. Not diameter of silver crystals, or anything like that - simply the fluctuations of the optical density, i.e. the fluctuations of the "transparency" of the developed emulsion, fluctuations that result from the gaps between the non-uniformly distributed silver crystals.
Further, see Leslie D. Stroebel, John Compton, Ira Current, and Richard D. Zakia (2000). Basic Photographic Materials and Processes. Focal Press. ISBN 0240804058. this is the second reference from the wiki article on film grain. Check from page 258.
see here http://books.google.com/books?id=BR...=ACfU3U0Jvob8U9WVhCYJDT0oqx77xSehJg#PPA258,M1
Here you can also read about what actually happens when you look through such a negative (or make an enlargement), as well as about the fact that the silver crystals are only "more or less opaque". As i wrote, they are very small. Very small grains of metal are getting less and less opaque, and they have even a different opacity on different wavelengths (i.e. some colors pass easier through them).
You can also read through this book http://books.google.com/books?id=DJ...=ACfU3U0G1mEb9UuFdUzkVBeUbITBlpMa7A#PPT106,M1 from page 90, gives a good idea about what happens with grain, why it depends on film speed and other parameters, and why it looks more apparent when the film is grossly over/underexposed. Further, what the difference is between traditional BW film grain and color negative film grain.
Finally, check the text on page 413 and further 415 in this book:
http://books.google.com/books?id=HH...=ACfU3U1704AE7mqHCpGWLYIHkAKK8JoHcA#PPA414,M1
about grain, why grain can be seen at low magnification...lo and behold, the book says, the sub-micrometer silver crystals ("largest is 2 micrometers) would need 50x or more magnification to be visible, but you can see graininess due to two reasons:
1: the random distribution in 3 dimensions lead to an apparent clumping that leads to a random irregular patter on a much largeer scale;
2: they may actually be clumped together physically,i.e. they are in real physical contact forming the random larger-scale patterns.
Check also on page 416 under title Factors ffecting negative granularity. Point 3 says clearly: granularity is the result of variations in density over small areas.
The grains you see in the negative or in a positive enlargement of it, are NOT the silver halide crystals - they are the light going through the gaps (more transparent regions) between the silver crystal clumps (more opaque regions). A random pattern of variation in the opacity (optical density) of the emulsion.
Are four specialized books on the subject enough for reference? i think i did my homework,now can i watch some movie?🙂
OK here's wikipedia, what it says further:
"Granularity is a numerical quantification of film grain, equal to the root-mean-square (rms) fluctuations in optical density, measured with a...bla bla."
Fluctuations in OPTICAL DENSITY. Not diameter of silver crystals, or anything like that - simply the fluctuations of the optical density, i.e. the fluctuations of the "transparency" of the developed emulsion, fluctuations that result from the gaps between the non-uniformly distributed silver crystals.
Further, see Leslie D. Stroebel, John Compton, Ira Current, and Richard D. Zakia (2000). Basic Photographic Materials and Processes. Focal Press. ISBN 0240804058. this is the second reference from the wiki article on film grain. Check from page 258.
see here http://books.google.com/books?id=BR...=ACfU3U0Jvob8U9WVhCYJDT0oqx77xSehJg#PPA258,M1
Here you can also read about what actually happens when you look through such a negative (or make an enlargement), as well as about the fact that the silver crystals are only "more or less opaque". As i wrote, they are very small. Very small grains of metal are getting less and less opaque, and they have even a different opacity on different wavelengths (i.e. some colors pass easier through them).
You can also read through this book http://books.google.com/books?id=DJ...=ACfU3U0G1mEb9UuFdUzkVBeUbITBlpMa7A#PPT106,M1 from page 90, gives a good idea about what happens with grain, why it depends on film speed and other parameters, and why it looks more apparent when the film is grossly over/underexposed. Further, what the difference is between traditional BW film grain and color negative film grain.
Finally, check the text on page 413 and further 415 in this book:
http://books.google.com/books?id=HH...=ACfU3U1704AE7mqHCpGWLYIHkAKK8JoHcA#PPA414,M1
about grain, why grain can be seen at low magnification...lo and behold, the book says, the sub-micrometer silver crystals ("largest is 2 micrometers) would need 50x or more magnification to be visible, but you can see graininess due to two reasons:
1: the random distribution in 3 dimensions lead to an apparent clumping that leads to a random irregular patter on a much largeer scale;
2: they may actually be clumped together physically,i.e. they are in real physical contact forming the random larger-scale patterns.
Check also on page 416 under title Factors ffecting negative granularity. Point 3 says clearly: granularity is the result of variations in density over small areas.
The grains you see in the negative or in a positive enlargement of it, are NOT the silver halide crystals - they are the light going through the gaps (more transparent regions) between the silver crystal clumps (more opaque regions). A random pattern of variation in the opacity (optical density) of the emulsion.
Are four specialized books on the subject enough for reference? i think i did my homework,now can i watch some movie?🙂
mh2000
Well-known
with the Nikon you have not reached the limit of C41 b&w film scanning at 4000dpi and you can see a difference when you scan lower or down sample, with an Epson you cannot see the difference between scanning at full resolution, 1/2 or down sampling by a factor of two (except that it helps smooth out the noise). For MF and the Nikon scans you may scan lower to keep your file size down if you don't intend on printing large, but that will be your choice... with the Epson it just isn't there. As to grain, the Epson does not resolve any level of grain or grain clumps... the Nikon does... though in truth, you are not actually capturing the full grain of any film with either.
ferider
Veteran
I have no idea how you guys get even close to C41 film resolution for 400 ASA and up. I am using a Nikon film scanner and am consistently limited by aliasing. Must be doing something wrong.
Roland.
Roland.
Svitantti
Well-known
...And nobody is or was arguing with this at any point.
Except that the black in a wet print is also silver-based density, so the silver(-grain) is again black (not the gaps). Of course in a scanned image which is then inverted there is no silver and the white parts are a result of the silver.
Still even in this case "grain" can mean either the white or black dots or just generally the texture.
Also it is not only the gap size in the negative that changes when film speed is changed (of film is developed differently), but also the size of the silver clumps, called grains are different size and shape, which I guess is very logical... Bigger clumps, when the silver crystals (or whatever they are) means there are more parts where the crystals are missing because they travelled to a clump.
More film speed means bigger clumps and bigger gaps, but still there are also smaller clumps in between.
russianRF
Fed 5C User
I'm baffled, Pherdinand. The very links you provided seem to argue against what you're advocating. From the very first link you provided:
"The exposed silver halide crystals are transformed during development into grains of silver that are more or less opaque, depending upon their size and structure (see Figure 11-1B). The developed silver grains seldom conform exactly to the shapes of the silver halide crystals. The size and shape of each silver grain depends upon the combination of exposure, developer type, and degree of development in addition to the size and shape of the original silver halide crystal. As the silver grains increase in size, the spaces between the grains through which light can pass freely become smaller. The overlap in the depth of individual silver grains results in a rather haphazard arrangement of silver grain clusters."
I cannot, for the life of me, get how you would read that passage as confirming your idea that grain itself is the space between the clusters of silver grain. The gaps, or holes, do indeed have to do with the optical density of the various parts of the emulsion, but the size, shape, and graininess seems to be determined by, well, the GRAIN of the silver.
I don't know how much further you want to argue this; you can't come up with anything to cite that directly supports your view; everything you have presented thus far, it seems, either does nothing to support you or actively refutes you.
"The exposed silver halide crystals are transformed during development into grains of silver that are more or less opaque, depending upon their size and structure (see Figure 11-1B). The developed silver grains seldom conform exactly to the shapes of the silver halide crystals. The size and shape of each silver grain depends upon the combination of exposure, developer type, and degree of development in addition to the size and shape of the original silver halide crystal. As the silver grains increase in size, the spaces between the grains through which light can pass freely become smaller. The overlap in the depth of individual silver grains results in a rather haphazard arrangement of silver grain clusters."
I cannot, for the life of me, get how you would read that passage as confirming your idea that grain itself is the space between the clusters of silver grain. The gaps, or holes, do indeed have to do with the optical density of the various parts of the emulsion, but the size, shape, and graininess seems to be determined by, well, the GRAIN of the silver.
I don't know how much further you want to argue this; you can't come up with anything to cite that directly supports your view; everything you have presented thus far, it seems, either does nothing to support you or actively refutes you.
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Pherdinand
the snow must go on
Oh my.
The silver crystals, call them silver grains if you like, are very small. Two micrometers at most, in photographic emulsions. It's in the text if oyu read further.
To see the silver crystals (call them silver grains if you prefer) you would need a rather strong magnification. This is also in the text if you read further.
In small magnification such as usual photographic enlargements, or scanning, the GRAINS or granularity of the image shows up mostly in uniform image areas like sky, skin tones, snow...etcetera. Is this true or not? I'd say it is.
Why? because the grains you see in photographic enlargements are NOT the image forming silver crystals, which are very very small, but the fluctuations in the optical density of the semi-opaque silver layer. The granularity of the image is coming from regions which are less opaque therefore light can pass easier i.e. gaps between the silver clumps, and these regions are much larger than individual silver crystal (call it grain if you prefer) sizes. A ten times enlargement shows already visible grain.
This is what is written there in all those books i quoted, and this is what is also logical if you look at a slightly enlarged negative as negative - grains are white - or, as positive - grains are BLACK.
It has NOTHING to do with the silver layer in paper enlargements - paper enlargements of course also have granularity but they are less visible than the granularity transferred from film, since the film is enlarged. Think about it: When you make a bigger enlargement, you get bigger grains, thus obviously it comes from the film.
Do you see WHITE grains in a photographic enlargement, a paper image? Or black grains? I personally always find the grains to be BLACK.
The silver crystals, call them silver grains if you like, are very small. Two micrometers at most, in photographic emulsions. It's in the text if oyu read further.
To see the silver crystals (call them silver grains if you prefer) you would need a rather strong magnification. This is also in the text if you read further.
In small magnification such as usual photographic enlargements, or scanning, the GRAINS or granularity of the image shows up mostly in uniform image areas like sky, skin tones, snow...etcetera. Is this true or not? I'd say it is.
Why? because the grains you see in photographic enlargements are NOT the image forming silver crystals, which are very very small, but the fluctuations in the optical density of the semi-opaque silver layer. The granularity of the image is coming from regions which are less opaque therefore light can pass easier i.e. gaps between the silver clumps, and these regions are much larger than individual silver crystal (call it grain if you prefer) sizes. A ten times enlargement shows already visible grain.
This is what is written there in all those books i quoted, and this is what is also logical if you look at a slightly enlarged negative as negative - grains are white - or, as positive - grains are BLACK.
It has NOTHING to do with the silver layer in paper enlargements - paper enlargements of course also have granularity but they are less visible than the granularity transferred from film, since the film is enlarged. Think about it: When you make a bigger enlargement, you get bigger grains, thus obviously it comes from the film.
Do you see WHITE grains in a photographic enlargement, a paper image? Or black grains? I personally always find the grains to be BLACK.
russianRF
Fed 5C User
It also says that the grains clump together. I realize what you're saying -- you're saying the grains are too small to see individually. Either way, this still doesn't prove your point about the "grain" we see actually being the holes. If the grains are microscopic, logically the holes between them are, too.
But grains clump together. So what?
You're good at referencing texts. I don't see you actually connect these texts to your point, though.
No, it is NOT true. Grain shows up EVERYWHERE. If you look closely at the details, it's there too. You'll read further in the links you provide that grain is essentially noise, and is in EVERY part of the picture.
And those fluxuations tend to be in clumps of silver atoms, hence, GRAIN.
So you claim. So you CLAIM. Nothing you've provided backs up what you say. You have given links that describe grain, but nothing says within those links that the grain effect we see is in fact the holes between the grains.
And yet you can never manage to find a place where these books you quote actually say what you're saying. Funny, that...
You know what? Peace. Believe what you want to believe; you obviously are going to whatever anyone says or whatever anyone points out. Just, look at what I, and other people, have said here to you. What we're TRYING to tell you. Maybe you can at least understand how you've failed to convince us...
40oz
...
I believe all Pherdinand is saying is that in a positive made from a negative, the image is formed by the light passing between the "grains" of silver. A white speck on a positive is evidence of silver blocking light on the negative. So if you see a black speck in an otherwise light sky, it's not evidence of "grain," but rather the absence of such in that particular spot on the negative.
Now, IMHO, what most people refer to as "grain" on a print is the interplay of light and dark in a region of little detail, such as the sky, not just the dark specks. If you look at the print under a magnifying glass, you aren't seeing litle black specks of "grain," but rather little black specks of the spaces *between* the "grains."
A rather esoteric distinction, but an entirely valid point.
Now, IMHO, what most people refer to as "grain" on a print is the interplay of light and dark in a region of little detail, such as the sky, not just the dark specks. If you look at the print under a magnifying glass, you aren't seeing litle black specks of "grain," but rather little black specks of the spaces *between* the "grains."
A rather esoteric distinction, but an entirely valid point.
Svitantti
Well-known
Yes 40oz and Pherdinand are right. The black parts of a positive image are the result of light passing through more opaque areas of a negative, where there are less silver atoms and more "empty space".
I just wonder why the only definition for "grain" would have to be the black parts of a positive image. As 40oz is pointing out, this is not the case in general talk and it is neither the only "real" definition of grain.
I just wonder why the only definition for "grain" would have to be the black parts of a positive image. As 40oz is pointing out, this is not the case in general talk and it is neither the only "real" definition of grain.
mh2000
Well-known
yup, the black things on my print are what I think of as "grain" ... never thought of it, but if they are black on my print they are clear on my negative... not that it changes anything for me.
Revolucion Artistico
Established
So, yeah despite what grain is or isn't i've been watching this thread because I just got my first scanner and really don't know what I'm doing and was hoping to get some useful tips or tutorials so any suggestions that may be of use would be most appreciated. Thanks in advance.
Ryan
Ryan
Revolucion Artistico
Established
So, yeah despite what grain is or isn't i've been watching this thread because I just got my first scanner and really don't know what I'm doing and was hoping to get some useful tips or tutorials so any suggestions that may be of use would be most appreciated. Thanks in advance.
Ryan
Ryan
Revolucion Artistico
Established
Whoa, sorry for the double post.
Pherdinand
the snow must go on
Yea, i'm really sorry for heavily hijacking this thread 🙂
Look guys, i am not arguing for the sake of arguing, and there's no need to say "peace". This is at the very end of my "to get angry about" list 🙂
I think we more or less agree with Svitantti actually, except that I think there is a clear definition of what people call "grain" in a photographic positive image; it is the dark speckles/dots, which obviously can only come from gaps in the silver of the emulsion. He says, no, grain is both the black specks and the white regions in between.
Well, a matter of definition, i guess, although i don't like to re-define well established notions but the physics will not change by this.
As to your point, russianrf: I am truly sorry that you still cannot understand what i am talking about. As i said before and as made clear by the other later posters here, think of what you see in a real case: you see black specks in the print, these can only come from transparent regions in the negative. If you need Ansel Adams to convince you about what you see, then i am sorry, i have no book of him to quote. If you are more willing to read through those pages what i pointed out (i am sure you read most of it but maybe you missed the point?) please check especially under the subtitle "what influences grain" or something like that, as i said in the first post when i mentioned the online book preview links.
I understand your feeling. I also don't like to believe every babbler on the Internet, especially when he writes something that contradicts directly what I thought before about the subject. Trust me I was also surprised when i realized - first came the experiment, i enlarged a piece of negative and inverted it and started thinking what the heck, how can silver grains be BLACK on the POSITIVE??? then i bumbed into the Schroeder's Negativ Praxis which has the nicest and easiest to understand description of how a photographic emulsion is constructed and what photochemistry does to it, and all became clear.
About referencing: Yes it DOES say in the text i pointed you to, that silver crystals are under 2 microns and 50 times magnification starts to show them, not less. But you have to find it yourself. When you asked abotu references, not having an online version of the Negativ praxis, i just looked randomly at the links on the Wiki page, and there it was, within 30 minutes i found it. So, good luck.
But really, it is not so important. Image is image, grain is there no matter if black or white, silver or gaps, so if there were no boring rainy winter evenings, maybe it was not worth so many words. 🙂
Have a good light (and gap-free silver clumps).
Look guys, i am not arguing for the sake of arguing, and there's no need to say "peace". This is at the very end of my "to get angry about" list 🙂
I think we more or less agree with Svitantti actually, except that I think there is a clear definition of what people call "grain" in a photographic positive image; it is the dark speckles/dots, which obviously can only come from gaps in the silver of the emulsion. He says, no, grain is both the black specks and the white regions in between.
Well, a matter of definition, i guess, although i don't like to re-define well established notions but the physics will not change by this.
As to your point, russianrf: I am truly sorry that you still cannot understand what i am talking about. As i said before and as made clear by the other later posters here, think of what you see in a real case: you see black specks in the print, these can only come from transparent regions in the negative. If you need Ansel Adams to convince you about what you see, then i am sorry, i have no book of him to quote. If you are more willing to read through those pages what i pointed out (i am sure you read most of it but maybe you missed the point?) please check especially under the subtitle "what influences grain" or something like that, as i said in the first post when i mentioned the online book preview links.
I understand your feeling. I also don't like to believe every babbler on the Internet, especially when he writes something that contradicts directly what I thought before about the subject. Trust me I was also surprised when i realized - first came the experiment, i enlarged a piece of negative and inverted it and started thinking what the heck, how can silver grains be BLACK on the POSITIVE??? then i bumbed into the Schroeder's Negativ Praxis which has the nicest and easiest to understand description of how a photographic emulsion is constructed and what photochemistry does to it, and all became clear.
About referencing: Yes it DOES say in the text i pointed you to, that silver crystals are under 2 microns and 50 times magnification starts to show them, not less. But you have to find it yourself. When you asked abotu references, not having an online version of the Negativ praxis, i just looked randomly at the links on the Wiki page, and there it was, within 30 minutes i found it. So, good luck.
But really, it is not so important. Image is image, grain is there no matter if black or white, silver or gaps, so if there were no boring rainy winter evenings, maybe it was not worth so many words. 🙂
Have a good light (and gap-free silver clumps).
Svitantti
Well-known
Yeah I think we agree on most parts. But I think we have to remember, that we can also talk about the negative, where for sure, the grain is the black parts because the rest is (virtually) empty and transparent.
Talking about prints, I've never even thought about it, I mean if a grain means white or black thing. Anyway the black parts are the grain of the paper in a wet print, but the white parts are a "projection" of actual grain in the negative. I think most people would agree that a grain can be any single "dot", be it white on black (shadows in a print) or black on white (highlights)...
Talking about prints, I've never even thought about it, I mean if a grain means white or black thing. Anyway the black parts are the grain of the paper in a wet print, but the white parts are a "projection" of actual grain in the negative. I think most people would agree that a grain can be any single "dot", be it white on black (shadows in a print) or black on white (highlights)...
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