Metering with film

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Alan Klein

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I shoot box speed and bracket +1 and -1 stops using Velvia 50 slide color and Tmax 100 BW in 120 MF roll film. I use a Minolta IIIa meter with reflective and incident capability. I have my film developed in a pro lab (they use Xtol for the BW). Even with the bracketing, I do screw it up especially in bad lighting more often than I would like. Any recommendations?
 

markbarendt

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I shoot box speed and bracket +1 and -1 stops using Velvia 50 slide color and Tmax 100 BW in 120 MF roll film. I use a Minolta IIIa meter with reflective and incident capability. I have my film developed in a pro lab (they use Xtol for the BW). Even with the bracketing, I do screw it up especially in bad lighting more often than I would like. Any recommendations?
With the Tmax I'd say simply avoiding underexposure should be plenty good, if you have done that the negative should be plenty good, during printing it should be very fixable. If you are having issues with prints from negatives it may simply be that you need to ask your lab to adjust.

As to problems with Velvia, how are you metering and what failures are you having?
 

Bill Burk

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I guess I don't need any more lessons in how to use Zone System ideas as both a communication tool and a communication barrier. I am doing a really good job of that.

Let's start with what I think it means to expose for the shadows... make the exposure good for them.

I totally forgot to mention that you start with a meter reading "of the shadow" - either a spotmeter or walk right up to the dark part of your picture if you like.

From this reading you can stop down three stops and go back to take the picture of the whole thing.

That will make that shadow turn out dark like it's supposed to be. That's what it means to expose for the shadows. You pick an exposure that will make the shadows come out right.

Now if you had chosen to use half box speed in the first place, instead of actually stopping down three stops, you will essentially stopped down two stops. Still fits the idea of "expose for the shadows".
 

RobC

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expose for the shadows means take care not to underexpose your negative. That's all and there's nothing more to it than that.
How you go about taking that care is a whole different barrel of worms, not least because you really don't want to underexpose your highlights either if you can possibly avoid it.
 

Arvee

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Thanks for all your replies. I thought my question was a simple one but obviously not! I don't print from negatives, only because I don't have the room to do it. Therefore I scan the negative. I know some of the church-goers on here wont like that because it involves an element of digital but that is the workflow available to me at the moment. I am not new to film (or photography) and when I used film before (when that's all there was) I had an old incident meter (Weston I think) and a separate sliding exposure calculator - the images normally came out fine. I recently exposed several rolls of film just guessing exposures (I forgot my meter) and they also came out ok, but because these days I have a good Sekonic meter than can do reflected spot, incident, flash, etc I was really just trying to find out how to put it to best use for some more reliable results. Some of the replies have made me feel I shouldn't have asked and put me off asking any other questions so from here on I think I'll just find my own way (as some have sTuggested there are various books published that idiots like me could read), however some of replies have been most helpful. Hopefully one day I will have room to print as well, at which point I can revisit some of my negatives. I will continue reading The Negative though, as it is interesting and clearly there are things I can learn from it.
Thanks,
Tom.
To answer your question, I also think current trends toward overexposure to bring up shadow detail makes for fat negatives and soft edges from irradiation. I was taught to keep the shadows down on the toe and the 'correct exposure' was the shortest one with the minimum amount of shadow detail. From the early days of photography, the old adage of 'you can't print what you don't have on the neg' applies to the situation when you weren't sure of the exposure, best err on the side of overexposure and you will most likely get a satisfactory print.

This 'shoot at half box speed and cut development by 15-20%' has evolved with the Zone System promoted by AA. It comes from The Negative which is regarded as the 'bible.' I, however, don't ascribe to that method and would like to suggest another well regarded text: Developing by Jacobson and Jacobson. It has a more conventional approach to exposing and developing/printing than Ansel's approach.

For example, shoot a roll of 125 speed at 64 with shortened development and a roll at 160 with normal development and examine under a microscope. The roll at 160 is going to have much better edge sharpness and less clumping than the roll exposed at 64; with half box speed you will even see bleed under the frame edges from light traveling/being dispersed through the emulsion due to excessive exposure. This becomes very evident when enlarging 35mm films but isn't necessarily a problem when using sheet film.

Also, when exposing to place all tonal values on the straight line portion of the curve you must compress tonal values in order to fit the image on printing paper, which has a shorter range of values and makes for a flatter looking print. Moving the exposure down towards the toe will give better tonal separation and will better fit the paper curve with more pleasing results, in my opinion.

Remember, there's always more than one way to skin a cat (no offense to cat lovers).
 
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removed account4

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Ah the joys of explaining spot metering and film latitude all at once. Giggle.
HA ! i had no clue that he was talking about spot metering, or spot metering shadows, i thought bill was talking about
metering at 3 stops beyond box speed, so everyting would have been over exposed by 3 stops
and in some strange universe it wasn't called stopping down :smile:

I guess I don't need any more lessons in how to use Zone System ideas as both a communication tool and a communication barrier. I am doing a really good job of that.

no worries bill, i took your post out of context i thought you were talking about something else
... i'm aware of the zs i just don't bother with it, and i didn't realize that is what you were talking about.

yeah i know, stopping my camera down 3 stops from shadow detail isn't really stopping my camera down 3 stops from box speed. it is a bit different :smile:

btw, i didn't read the post you had originally quoted from it was a bit l o n g , and my attention span is a bit short so i tend to ignore the long posts, unless they are to the point or i find them to
be interesting at least. i don't find anything about the zone system or plotting curves
or densitometry or sensitometry or arguing that grey isn't grey to be interesting so i move on to the next post.
 
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RobC

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I would just like to point to everyone that it doesn't matter one iota what EI or speed you use on your meter becasue your meter doesn't expose the negative. What matters is where you place the exposure on the film curve and that depends on how you interpret your meter reading to do that.
For example using half box speed as your meter setting does not imply that you are giving one extra stop of expsoure which is what a lot of people are wrongly suggesting. The purpose of it from a zone system perspective is to allow you to develop a SBR of 10 stops onto a film density range which fits the paper. That is something very different than over exposing by 1 stop. You should end up with a negative density for a zone 3 which is very similar to using ISO speed and closing down 2 stops. The reason people argue about it becasue they don't understand sensitometry and the zone system so they tell you to use something else.
As I said earlier in topic, if you are using ISO speed and manufacturers recommended dev, then you can consider each zone as 0.7 of a stop.

So if you were using ISO 400 speed film at box speed and got an exposure reading of 1/60 @ f8 for zone 3 then you close down 2 zones which would be 0.7 x 2 = 1 1/2 stops to get an exposure of 1/60 @ f13.1.
If on the other hand you were using half box speed and reduced dev then you use 1 zone = 1 stop and you would get a meter reading of 1/60 @ f5.6 and then close down 2 full stops which would give you 1/60 @ f11.
So infact all you are doing at zone 3 is giving just a half a stop extra exposure which with the reduced dev would be equivalent to less than a half stop stop difference resulting in very similar negative densities in the shadows as using full ISO speed.
And when it comes the highlight densities the reduced dev would give much more significant reduction in negative densities when using half box speed so overall the subject range would be getting lower resulting negative densities than by not using half box speed and reduced dev.
So where all this over exposure bollocks is coming from I have no idea except by people who don't understand it. The only thing that is increased minimally are the shadow densities. What the frigging meter reading says is irrelavant. Its the resulting negative densities that matter.
 

pentaxuser

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To answer your question, I also think current trends toward overexposure to bring up shadow detail makes for fat negatives and soft edges from irradiation. I was taught to keep the shadows down on the toe and the 'correct exposure' was the shortest one with the minimum amount of shadow detail. From the early days of photography, the old adage of 'you can't print what you don't have on the neg' applies to the situation when you weren't sure of the exposure, best err on the side of overexposure and you will most likely get a satisfactory print.

This 'shoot at half box speed and cut development by 15-20%' has evolved with the Zone System promoted by AA. It comes from The Negative which is regarded as the 'bible.' I, however, don't ascribe to that method and would like to suggest another well regarded text: Developing by Jacobson and Jacobson. It has a more conventional approach to exposing and developing/printing than Ansel's approach.

For example, shoot a roll of 125 speed at 64 with shortened development and a roll at 160 with normal development and examine under a microscope. The roll at 160 is going to have much better edge sharpness and less clumping than the roll exposed at 64; with half box speed you will even see bleed under the frame edges from light traveling/being dispersed through the emulsion due to excessive exposure. This becomes very evident when enlarging 35mm films but isn't necessarily a problem when using sheet film.

Also, when exposing to place all tonal values on the straight line portion of the curve you must compress tonal values in order to fit the image on printing paper, which has a shorter range of values and makes for a flatter looking print. Moving the exposure down towards the toe will give better tonal separation and will better fit the paper curve with more pleasing results, in my opinion.

Remember, there's always more than one way to skin a cat (no offense to cat lovers).

I must admit that the example you give and its results are new to me. Given the latitude of B&W neg film to over-exposure what is it that causes a half stop speed decrease to exhibit less edge sharpness and bleed under the the frame edges Does a half stop more exposure really equate to excessive exposure sufficient to cause bleed and noticeable edge sharpness?

Can you give me a link to the publication of Developing by Jacobson and Jacobson?

Thanks

pentaxuser
 

RobC

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and another thing. The zone system is about ensuring resulting print detail resolves where you want it to resolve. So zone 3 just has full textural detail and zone 7 is just before you start to lose highlight detail. Neither of those two desireables are compatible with under or over exposure of the negative so any ideas that using zone system resulting in 1/2 box speed causes over exposure is pure nonsense.
 

markbarendt

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I must admit that the example you give and its results are new to me. Given the latitude of B&W neg film to over-exposure what is it that causes a half stop speed decrease to exhibit less edge sharpness and bleed under the the frame edges Does a half stop more exposure really equate to excessive exposure sufficient to cause bleed and noticeable edge sharpness?

Can you give me a link to the publication of Developing by Jacobson and Jacobson?

Thanks

pentaxuser
Taking a scientific wild ass guess here that the irradiation Fred talks about is really flare providing a softening of contrast rather than a reduction in sharpness. The degree of problem would be related to the lens's character more than the exposure level. For example some lenses cope very well when shooting toward bright light sources, others don't.
 

RobC

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you're only getting half a stop extra exposure so you take any point on the curve and say well its getting half a stop more exposure than a point below it so it must be bad and you could say something in zone 7 is getting 4 stops more exposure than zone 3 so it must be terrible compared to zone 3.
Clearly any idea of soft edges due to irradiation is complete nonsense. Soft edges are far more likely due to using a diffusing enlarger and/or mis aligned enlarger rather than anything else.
 

Arvee

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you're only getting half a stop extra exposure so you take any point on the curve and say well its getting half a stop more exposure than a point below it so it must be bad and you could say something in zone 7 is getting 4 stops more exposure than zone 3 so it must be terrible compared to zone 3.
Clearly any idea of soft edges due to irradiation is complete nonsense. Soft edges are far more likely due to using a diffusing enlarger and/or mis aligned enlarger rather than anything else.

Disagree! Go outside on a bright, sunny day (I know you don't get many in the UK!) and use your method of exposure. Expose for the shadows making sure you include the bright sky. Develop the negs. Now, examine the junction where the sky meets the rebate (the area beneath the frame edge) with a 10X loupe. You will see the high density in the sky and when you look closely you will see the high density sky fade gradually into gray before disappearing into clear rebate. This softens the edge of the boundary.

Ideally this should be a sharply defined edge where the sky ends in the neg and the rebate begins. This gray boundary is about 0.10-0.25 mm wide before disappearing into the rebate, depending on the amount of exposure. What you're seeing is the light scattering (irradiation) within the emulsion (photons bouncing around in the emulsion and exposing adjacent grains). The amount of scattering/bleed is directly proportional to the amount of (over)exposure.

This phenomenon occurs at any juncture within the neg where there are light/dark boundaries. An exaggerated version of this is halation where you photograph bright lights at night and you get tons of bleed around the light source.

I see irradiation whenever I have included a chunk of sky while photographing in shadow, which will be several stops difference and the amount of bleed is huge.

If this doesn't convince you, make a 16x20 from a 35mm neg that is shot at half box speed and one shot at 1.25X box speed of the same subject and notice the crispness in the thinner neg. I guarantee you will see it.

PS. In larger formats you can afford to be sloppy with exposure; with miniature formats you aren't afforded that luxury simply because of the smaller magnification factors needed with larger formats when making 8x10 and larger prints. In 35mm negs, the shortest exposure that allows the minimum amount of shadow detail will make the sharpest print.

Bottom line: (in smaller formats) if you don't think there is a price to be paid for enhanced shadow detail, think again! You're trading sharpness for shadow detail. There is no free lunch!!
 
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RobC

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Disagree! Go outside on a bright, sunny day (I know you don't get many in the UK!) and use your method of exposure. Expose for the shadows making sure you include the bright sky. Develop the negs. Now, examine the junction where the sky meets the rebate (the area beneath the frame edge) with a 10X loupe. You will see the high density in the sky and when you look closely you will see the high density sky fade gradually into gray before disappearing into clear rebate. This softens the edge of the boundary.

Ideally this should be a sharply defined edge where the sky ends in the neg and the rebate begins. This gray boundary is about 0.10-0.25 mm wide before disappearing into the rebate, depending on the amount of exposure. What you're seeing is the light scattering (irradiation) within the emulsion (photons bouncing around in the emulsion and exposing adjacent grains). The amount of scattering/bleed is directly proportional to the amount of (over)exposure.

This phenomenon occurs at any juncture within the neg where there are light/dark boundaries. An exaggerated version of this is halation where you photograph bright lights at night and you get tons of bleed around the light source.

I see irradiation whenever I have included a chunk of sky while photographing in shadow, which will be several stops difference and the amount of bleed is huge.

If this doesn't convince you, make a 16x20 from a 35mm neg that is shot at half box speed and one shot at 1.25X box speed of the same subject and notice the crispness in the thinner neg. I guarantee you will see it.

PS. In larger formats you can afford to be sloppy with exposure; with miniature formats you aren't afforded that luxury simply because of the smaller magnification factors needed with larger formats when making 8x10 and larger prints. In 35mm negs, the shortest exposure that allows the minimum amount of shadow detail will make the optimal print.
But this is due to diffraction around the edge of the rebate/frame. That should be obvious to you.
 

pentaxuser

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Thanks Fred. I googled Jacobson and Jocobson and found what I think may be your link although you haven't given a link in your reply. I had tried to skim read it( about 300 pages covering formulas and darkroom set-up etc) and I couldn't find any reference to increasing box speed for a better image

It has been revised many times since its initial publication in about 1940 but the latest reprint was about 1980 and I felt that it still reflected the 1940's film technology in terms of its content. It says for instance that an increase of 10 F in developer temperature should result in a 50% reduction in development time whereas most current tables show a lower percentage reduction and its recommendation in development time reduction for continuous agitation is much greater than seems to be currently recommended.

I do wonder how much of the publication still applies to current films, developers etc

I'd appreciate it if anyone else here has the time to look at the publication and give their views. If you google Jacobson and Jacobson it will get you to the publication which you can download for free to read. It is called a "Focal Manual of Photo Technique"

Thanks

pentaxuser
 

Arvee

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Call it what you will. It also occurs anywhere in the neg where there are adjacent boundaries of very bright and dark subjects and it destroys sharpness. Go make a 16x20 and get back to me!
 

RobC

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and so it may be but you need a lot of over exposure for that and halfing box speed and reducing development doesn't cause more than a stop and most likely only half a stop if you get it right. Now if we are claiming thats going to cause a problem then you are wasting your time using film and should move to digital.

It's being frightened by your own shadow if you think its something to worry about in normal everyday photography, even when you have fairly high contrast subjects.
 

Arvee

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Thanks Fred. I googled Jacobson and Jocobson and found what I think may be your link although you haven't given a link in your reply. I had tried to skim read it( about 300 pages covering formulas and darkroom set-up etc) and I couldn't find any reference to increasing box speed for a better image

It has been revised many times since its initial publication in about 1940 but the latest reprint was about 1980 and I felt that it still reflected the 1940's film technology in terms of its content. It says for instance that an increase of 10 F in developer temperature should result in a 50% reduction in development time whereas most current tables show a lower percentage reduction and its recommendation in development time reduction for continuous agitation is much greater than seems to be currently recommended.

I do wonder how much of the publication still applies to current films, developers etc

I'd appreciate it if anyone else here has the time to look at the publication and give their views. If you google Jacobson and Jacobson it will get you to the publication which you can download for free to read. It is called a "Focal Manual of Photo Technique"

Thanks

pentaxuser
Yep, I have the updated/revised 1980 edition and 99% still applies. The only differences between now and then is that film manufacturers got the bean counters involved and they started finding ways to cut factory costs and increase profits. Hence, we now have films that don't have as much silver in them as we had in the 70s through the 90s. It's a very good book and when I got my degree in Photography that was the bible. Ansel hadn't made his mark on the general photographic population back then.

As an aside, when I was in school I had a classmate, a brash, young upstart named John Sexton, who believed in Jacobson's way of doing things but then he was accepted as a acolyte in Adams' church one summer and he hasn't looked back since!

Get the book if you can; I picked mine up for $1.39 plus $3.99 shipping. It's a gem. For info on ideal exposure check pp. 68 (depends on the edition) to see the complete picture. Sometimes I get the impression that Steve Anchell may have used Jacobson as a rough foundation for The Film Developing Cookbook.
 
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Arvee

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and so it may be but you need a lot of over exposure for that and halfing box speed and reducing development doesn't cause more than a stop and most likely on half a stop if yo get it right. Now if we are claiming that going to cause a problem then you are wasting your time using film and should move to digital.

It's a fear of shadows
Rob, get and read Jacobson's book then talk to me; you're just rambling!!
 

RobC

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Now let me see, film manufacturers claim resolution of upto 200 lp/mm in relatively normal b+W film. 100-150 lp/mm being more realistic for their lab tests. These tests are done at a contrast ratio of 1000:1 which is 10 stops or so. And they use alternating black and white lines as test targets I believe.
More realistic for us mortals would be upto 100 lp/mm.

So they are able to get the little test targets to resolve down to 0.0025mm using a 10 stop contrast ratio but I need to be worried about a contrast ratio of much less than that causing me soft edges in my negs. And we are talking micro contrast here. For us mortals we can resolve upto around 0.01mm in our negs.
Why the hell would I want to get and read a book which will make me fear my own shadow or are the film manufacturers and everyone else who has done resolution tests of their own negs, lying about what they are abale to achieve. The vast majority of micro contrast will be much much lower contrast ratio. The manufacturers give us 1.6:1 as a low value which cuts resolution down a big chunk which is very odd since its says that the less contrast there is, the lower the resolution which means the more edge contrast there is the better the resolution which is completely at odds with what you and your book are telling us.

And halation is caused air/surface boundaries and reflection from film backing plate which has been utilised by infra red film manufacturers to get that characteristic bloom in IR film shots. They didn't use antihalation dyes in their films. Normal films have it though. I guess its like a lens coating for films. They've improved too, so much so that they can get film resolution of 200 lp/mm (ignoring the massive numbers claimed by some specialist films like 800 lp/mm).
I may be rambling, but not like a parrot who read something somewhere.
 
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removed account4

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John:

"half box speed" results in a one stop increase of exposure.

"stop down three stops" results in a three stop decrease of exposure.

+1 - 3 = -2 (i.e. a two stop decrease in exposure)


thanks matt !

i was suffering from a carb overload
i appreciate you helping me through this difficult time !

john
 

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I have seen the effect Fred is talking about in my scans of Acros where the highlights have burned across other details, only really noticed it because I ran around and shot a roll of Ektar at the same time. This was lab developed and I realised eventually by a little judicious pseudo testing that this particular lab was always overdeveloping by at least 1/3 of a stop. OK pretty extreme example as on very bright days the SBR may have been well into double digits, but is it clear or agreed that burned out highlights is what Fred is talking about?

I also disagree strongly btw with the notion that here in the UK we don't get such scenarios. Anyone who lives on the south coast knows that due to our location on the globe very strong shadows can be prevalent whilst also getting the direct blast of light from the sun over the sea to the south. This time of year in particular is often the worst for it because the sun is still low in the sky.
 

David Allen

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"Granularity/graininess is directly related to density. More exposure = higher density. Higher density = more grain".

"For example, shoot a roll of 125 speed at 64 with shortened development and a roll at 160 with normal development and examine under a microscope. The roll at 160 is going to have much better edge sharpness and less clumping than the roll exposed at 64; with half box speed you will even see bleed under the frame edges from light traveling/being dispersed through the emulsion due to excessive exposure".

"Bottom line: (in smaller formats) if you don't think there is a price to be paid for enhanced shadow detail, think again! You're trading sharpness for shadow detail. There is no free lunch!!"


Sorry guys but I just don’t get this. If what you are stating is true all of us will be getting grainy highlights with reduced detail.

Why?, well the highlights in any image will have received far far more exposure than the mid-tones and shadow areas. The highlights in any scene will always have far more density on the negative than the other values. This is an incontrovertible fact. Therefore, if the above statements were correct, I and others here would have witnessed grainy unsharp highlights in every photograph that we have ever made!

"Ansel Adam's Zone System is for sheet photography".

This is the usual uninformed statement that keeps recurring. The Zone System is first and foremost a system designed to promote visualization. This was defined by Ansel Adams as “the ability to anticipate a finished image before making the exposure”. This, to me, is the key to the Zone System. People seem to always get bogged down in the mechanical side chasing a mythological 'prefect' negative or one that prints 'easily'. However, the Zone System is really only a means to a desired end. If you read any book about the making of Ansel Adams prints you will note that, for many of his most famous images, the negative bag had a note from Ansel stating that the negative was difficult to print. This does not mean that he screwed up the exposure/development but rather that, to achieve his desired rendering of the scene that he had visualised, required a lot of hard work in the darkroom. If you wish to apply the principles of the Zone System to roll film, there are plenty of versions of the Zone System that are designed specifically for roll film users (such as my Dad’s Zone VIII system for example).

However, all of this debate is somewhat irrelevant because the key question for any photographer is how do I want my final image to look? If the image requires shadow detail then you have no choice but to expose your film to achieve this. If shadow detail is not important for you, then clearly it plays no important factor in deciding upon what exposure is best to use.

Bests,

David.
www.dsallen.de
 

Anon Ymous

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"Granularity/graininess is directly related to density. More exposure = higher density. Higher density = more grain".
...


Sorry guys but I just don’t get this. If what you are stating is true all of us will be getting grainy highlights with reduced detail.

Why?, well the highlights in any image will have received far far more exposure than the mid-tones and shadow areas. The highlights in any scene will always have far more density on the negative than the other values. This is an incontrovertible fact. Therefore, if the above statements were correct, I and others here would have witnessed grainy unsharp highlights in every photograph that we have ever made!

It is true that granularity in BW negative films increases with density. If you have a look at a film datasheet that quotes RMS granularity, then you'll notice that it is always read at density = 1 etc etc. But while that is true, it is also true that the perceived granularity (in the print) also changes with density. I've noticed that it is much easier to spot grain in mid tones, compared to light (or dark) ones. If you wanted to make an objective comparison, then you'd have to print both highlights and any other thinner part to the same (print) density.

BTW, that's not the case with C41 films, where denser parts have finer grain.
 

David Allen

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It is true that granularity in BW negative films increases with density. If you have a look at a film datasheet that quotes RMS granularity, then you'll notice that it is always read at density = 1 etc etc. But while that is true, it is also true that the perceived granularity (in the print) also changes with density. I've noticed that it is much easier to spot grain in mid tones, compared to light (or dark) ones. If you wanted to make an objective comparison, then you'd have to print both highlights and any other thinner part to the same (print) density.

BTW, that's not the case with C41 films, where denser parts have finer grain.

I am not interested in what RMS charts state. I am only interested in how my prints look. Everyone will have noticed that grain is most noticeable in uniform mid-grey areas. Now these uniform mid-grey areas will have received more exposure (are denser) than the shadows and have received considerably less exposure (have less density) than the highlight areas.

However, going back to my main point, if you require shadow detail for how you have visualised the image then you have no choice but to expose sufficiently to record this information. In my photographs I want good detail in the appropriate shadows. In certain situations (such as an image that includes a dark courtyard whose walls have been blackened by years of people burning brown coal and also a white wall in full sunlight) I will have to give much much more exposure to render the important shadows than a more general scene where, perhaps, there are not significantly large shadow areas that require detail. The exposures are wildly different and have very different densities. When I hang an exhibition with, say, 40 prints, do the prints from denser negatives look grainier or not so sharp as the prints from the less dense negatives. Simple answer is no!

Bests,

David.
www.dsallen.de
 

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The exposures are wildly different and have very different densities. When I hang an exhibition with, say, 40 prints, do the prints from denser negatives look grainier or not so sharp as the prints from the less dense negatives. Simple answer is no!

Grain is not apparent until you see a certain enlargement at a certain distance that makes it apparent. You have to pass a certain enlargement threshold in order to even perceive grain.
Said in other terms, if you print mid-tone details of those different negatives at several, increasing enlargements, the denser negative will begin showing perceived graininess earlier (at lower enlargements) than the less dense negative.
If both of them are printed and visualized below the "perceptibility" of grain by the human eye, the result is the same.

What you say about perception of grain in an exhibition can certainly be true because the enlargement and distance of vision are such that the "threshold" of perceived graininess is not reached for any picture.

As a hybrid workflow photographer I inspect pictures with a scanner. The graininess of a colour negative can be "shocking" if you are used to slide film. For a film, the higher the density, the higher the grain. For a negative film, the brighter the subject, the higher the density, the higher the grain. Uniform bright areas such as a blue sky look very, very much more grainy with negative than with slide film, because highlights areas are areas of high density in negatives, and of low density in slide film.

Density is certainly correlated to graininess, but that doesn't necessarily mean that grain is always perceptible. When you print Lf or Medium Format negatives you can easily remain below the threshold of perception. 135 makes grain considerations relevant.
 
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