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Shtativ
17-May-2006, 12:48
Hallo, friends!

I heard opinion, that b&w films (unlike color) can be never replaced by a digital matrix. Explain my why, please? I understand, that the question can seem silly, but it not so. I know what pleasure the photographer during in analog development and a press of photos prints. For me interesting the technical moments only. Why b&w films will live it is eternal?

Donald Qualls
17-May-2006, 16:02
I heard opinion, that b&w films (unlike color) can be never replaced by a digital matrix. Explain my why, please?

"Replaced", perhaps not -- B&W film has a distinctive grain structure, modified by the way it was exposed and processed, even the way it was printed or scanned. No digital sensor will, natively, have such a structure; it'll have the same regular grid of sensels as every other sensor, and each sensel will output a value that's displayed as a shade of gray (in B&W imaging). If you use enough gray shades (256 usually isn't quite enough, but 16 bits per channel, 65,536 values, is plenty) the result is a very, very creamy image.

However, B&W film and B&W printing media also have a "curve" -- a non-linear response of developed density relative to exposure, which is also affected by the developer and technique used, and by how much exposure was given above the film's threshold. Digital sensors, as generally designed, don't; their response is perfectly linear over the entire accessible range (which is to say, the nonlinear parts of the range are clipped before the image is every recorded).

Now, it's very easy to apply a curve to a raw digital image to emulate the reponse of a particular film and developer, though this is very rarely done -- most of the past century, B&W photographers have wished for a perfectly linear response. It's *not* easy to add realistic looking grain to a digital image, however, and most photographers old enough to have learned on film are used to seeing grain, even if it's at an almost-subliminal level.

I've seen some spectacular images shot originally in B&W with digital sensors -- Kodak made a high quality B&W-only digital cam back when 1.3 Megapixels was expensive, and there are a couple infrared conversions that work in B&W only as well. I like those images.

I won't be making any of them any time soon, though, because I like film, too, and I can *afford* film -- a top end digital camera capable of making excellent B&W images is well beyond my budget. A 1927 roll film camera can do the same for an outlay of under $100 plus film and processing, and that can be paid for a bit here and a bit there instead of all in one big debit card transaction.

http://i11.photobucket.com/albums/a183/dqualls/Voigtlander%20Rollfilmkamera/dfdb8ce9.jpg

Maris Rusis
17-May-2006, 22:47
Three big reasons for me to use black and white film are:

1. Black and white can access more subject matter variations than colour. Every filter change means a different look is available. A landscape with a black sky achieved by using a red filter has very different impact to a landscape with a white sky made by using a blue filter. Getting the right subject matter that expresses what you want your photograph to say is a big problem in photography. Black and white makes this easier.

2. The brain recognises a black and white picture as an abstraction and processes it by analytical means. Colour tends to be processed in the optic lobe and most viewers are finished with the picture as soon as they recognise the subject matter. If you want to show something that needs thinking about, complex or profound, black and white is better.

3. A black and white primary photograph, usually a negative, contains stuff that used to be part of the subject, that has travelled across space at 300 000 Km/sec. and imbedded itself in the photographic emulsion. It gives me goose-bumps to realise that when I hold a negative I also hold a small sample of the subject. Colour transparencies are also primary photographs but because they are made by a reversal process they are formed from what was not exposed in the camera. Digital pictures do not include physical traces of subject matter so no goose-bumps!

tim atherton
18-May-2006, 08:15
2. The brain recognises a black and white picture as an abstraction and processes it by analytical means. Colour tends to be processed in the optic lobe and most viewers are finished with the picture as soon as they recognise the subject matter. If you want to show something that needs thinking about, complex or profound, black and white is better.


why do most painters use colour?

Marko
18-May-2006, 08:30
3. A black and white primary photograph, usually a negative, contains stuff that used to be part of the subject, that has travelled across space at 300 000 Km/sec. and imbedded itself in the photographic emulsion. It gives me goose-bumps to realise that when I hold a negative I also hold a small sample of the subject. Colour transparencies are also primary photographs but because they are made by a reversal process they are formed from what was not exposed in the camera. Digital pictures do not include physical traces of subject matter so no goose-bumps!

Maris, the first two reasons why you prefer b&w film are technically correct, but only in relation to color film. Those have nothing to do with digital. Digital, especially when shot in RAW, beats any kind of film hands down when it comes to ease of processing or deriving effects. The reason for this is that any corrections, filtering or such are happening after the exposure has already been made, during post processing. That has been one of the major ralying points for the anti-digital crowd, very much the same as the great painting vs. photography two centuries ago or so.

As for your third reason, I understand what you are thinking, and there is certainly some poetry in it, but, please forgive me for being blunt, it doesn't make much sense. It's just physics (and chemistry) - light is made of photons, immaterial theoretical particles, and abstract really, that impact the emulsion particles in the film and deliver part of the energy they carry in the process. It's that energy that forces the silver salt particles to change state and become less stable than unexposed ones. That's all physics that makes it easier to separate the silver from the other components of the salt later during chemical process.

Just think about it - if there were any real particles traveling from the object, they would surely have to pass the solid glass of your lens, all the elements in it, before they hit the film and "embed" themselves in it. Doesn't sound very possible, does it? But let's disregard that for the sake of an experiment, let's just assume we're using a pinhole camera, and that those particles do embed themselves into the film. Then comes chemistry, a very aggressive and more profoundly altering process than physics. And so on, you should get the picture by now.

All being said, there are several very valid reasons, both objective and subjective, for using film over digital for b&w:

1. Objective reasons: the bayer matrix, extremely long exposures, infrared, to name just a few, without going into detail.

2. Subjective reasons are many - initial outlay, computer skills or lack thereof, even just the fun aspect of it (my primary reason for getting back to film).

3. There is also one reason that could fit both categories, and that's long-term preservation. That's a topic in and of itself and best left for other discussions.

Regards,

Marko

Joseph O'Neil
18-May-2006, 09:32
why do most painters use colour?

Warning - NON-expert attempting to answer a question..
:)

Availability of materials. Colour pigments for painting have been around since the time of the Pyramids, probally earlier - maybe even the first rock art drawings. So the mindset of humanity is, paintings are a medium done in colour. I wonder if paintings done in B&W would sell very well, becasue of public expectation.

Also, we could vagely define art as capturing emotion into a physical medium. Colour alone, without images, can invoke emotion, so colour is a better mdeium in that sense.

Photography conversely, was all black & white in it's infancy. Colour as a "standard" for the home / family use did not become the norm until - oh - I am guessing - later 1960s. So you had a huge body of work, and a few generations of people who saw B&W photography as the norm or status quo. Even now, you sit down and watch "classic" movies such as "Casablanca" or "It's a Wonderful Life", what do you have - B&W photography. So B&W as a medium for photography is well entrenced in the public mind, even those who may not like it, they are used to it.

One last thought - many artists I know who work in colour also do charcoal or pencil art, especially as an initial study before a painting.

Or conversely - with tounge firmly planted in cheek - ask why do sculptors not work in colour? Why isn't Michaelangeo's statue of David in colour?

:)

joe

tim atherton
18-May-2006, 10:49
So colour could actually be the better choice in photography over time... :-)

Or conversely - with tounge firmly planted in cheek - ask why do sculptors not work in colour? Why isn't Michaelangeo's statue of David in colour?

point of interest, many of what we consider the "classical" greek sculptures were originally in colour..

j.e.simmons
18-May-2006, 10:54
Remember that photons are considered both particles and waves.

It's been my theory, met with blank stares by the real scientists I've presented it to, that negatives are affected by the particle property of the photon striking and changing the silver (thus supporting Maris), and that digital sensors react to the wave property producing an electrical current (supporting Marko).

Thus, in true post-modernist style, it seems everyone is correct. Smoke that.
juan

Maris Rusis
18-May-2006, 16:24
Black and white is powerful and not just in photography. Coloured ink has been around for centuries but all the great novels have been printed in black and white.

paulr
18-May-2006, 17:06
3. A black and white primary photograph, usually a negative, contains stuff that used to be part of the subject, that has travelled across space at 300 000 Km/sec. and imbedded itself in the photographic emulsion.

what stuff would that be ... karma?

Michael Graves
18-May-2006, 17:20
"Thus, in true post-modernist style, it seems everyone is correct. Smoke that."

Or as my wife would say, "I'm right and you're wrong. Live with it. Now, what were we talking about again?"

paulr
18-May-2006, 17:24
Remember that photons are considered both particles and waves.

It's been my theory, met with blank stares by the real scientists I've presented it to, that negatives are affected by the particle property of the photon striking and changing the silver (thus supporting Maris), and that digital sensors react to the wave property producing an electrical current (supporting Marko).

Thus, in true post-modernist style, it seems everyone is correct. Smoke that.
juan


well, it's a pretty thought. but even though i have more formal training in postmodern mumbo jumbo than in science, i think i'd have to smoke something stronger that that explanation to buy the idea. as more than a metaphor, anyhow.

for one thing, light was never a part of the subject you photograph. It was energy that bounced off of it.

for another, light doesn't embed itself in anything. if you stop a photon, it disintigrates into other forms of energy.

while the exact mechanics of what happens when a photon strikes a silver halide molecule are still unknown (as far as i've heard), it's presumed to be quantum effect. They believe the photon releases energy into the halide molecules, bumping certain electrons to a higher energy state, making the halide crystal unstable in specific ways.

this just allows the halides to be more easily reduced to metalic silver. the only 'residue' was energy, and it was primarily influencing the atoms that were clinging to the silver. The part of those halides that responded to the light energy gets washed away in the fix.

it's true than in certain respects photons behave as particles, but unlike particles they cannot be captured. they never sit still.

hope this isn't a buzz kill.

maybe it's karma that gets captured by the film.

Allen Quinn
18-May-2006, 18:13
what stuff would that be ... karma?

Since we all work with reflected light, my advice is:
Be careful what you bounce off your subject (:

Maris Rusis
21-May-2006, 17:58
Discussions of physics are somewhat off-topic in a thread on B&W but they may assist understanding of what a truly august thing a photograph is.

An object, to be a photographic subject, must in part be composed of light. More technically, potential photographic subjects must harbour an electromagnetic force field of appropriate wavelengths. These wavelengths are those characteristic of visible light. The electromagnetic force field penetrates the subject all the way through in the case of transparent things (that's why they are transparent) and only a short distance in the case of opaque or highly reflective things. While the field is inside the subject it is affected by the electron clouds of the fermions (atoms and molecules in the case of ordinary matter) and becomes changed in characteristic ways that we recognise on sight. Thats why sulphur is yellow, grass is green, etc).

Electromagnetic force fields are not static but arrive, interpenetrate matter, and move on very quickly; about 300 000Km/hr for a vacuum and a bit less for environments where the refractive index is greater than one such as inside a photographic lens.

While I could talk of the field radiating from the subject towards the film I could use other words. Modern quantum electrodynamics allows forces, including the electromagnetic force, to be treated as particles. These particles are termed bosons and in the case of electromagnetism the characteristic boson is called a photon.

The photons (or fields, or forces, however you want to do the mathematics) really were part of the subject and when they arrive at the film deposit their energy in silver halide crystals and cause chemical changes usually referred to as a latent image. A film is heavier after acquiring a latent image, less than a billionth of a billionth of a gram heavier, but the difference is not zero. Something has travelled across and stuck!

What to do with a latent image is familiar to every photographer and agonising over quantum physics does not help at all.

paulr
21-May-2006, 22:09
Modern quantum electrodynamics allows forces, including the electromagnetic force, to be treated as particles.

Yes, but it doesn't allow us to treat them as particles on a whim--only in the ways they behave as particles. There are ways in which they do not behave as particles, too.


A film is heavier after acquiring a latent image, less than a billionth of a billionth of a gram heavier, but the difference is not zero. Something has travelled across and stuck!

Anything that takes on energy gains mass. Whether it's from sunlight, a chemical reaction, the toaster, the microwave, or because you ironed it. Things also take on mass if you accelerate them, or lift them farther from the center of the earth. This is all simple relativity.