Help With Metering

[Barney]

Good Evening everyone,

I have identified another deficiency in my methodology, "oh no you haven't" I hear you all cry.

I am using a light meter and using the incident light reading for exposure. However, in digital I am a great fan of the spot meter and exposure lock facility where I mentally identify the, what appears to me, mid tone and lock up on it.

My question is that with an incident light meter how may stops difference are the between bright sky and dark undergrowth? I would like to think there is a method to calculate theses things without resort to guesswork, I need to have an element of input into the process of exposure.

 

[Plain Nev]

Well, I suppose you could meter for the sky, and then the undergrowth and see what the difference is. Is there any reason you are using incident reading though?

 

[FishyFish]

Are you using it as an incident meter? If so, just hold the meter in front of the subject with the dome facing the camera. You're recording incident light, which is the light falling onto the subject, not the light reflected back (as with a spot meter reading).

If the subject is further away and in different light, e.g. you're in shadow and the subject is in sunlight, then you'll need to compensate.

 

[StephenM]

An incident light reading is basically taking a reading from an artificial highlight (the inside of the white dome). Using the meter in the shade and in full sunlight will give you a measure of how much difference there is between full sun and shade, but won't give you an idea of the number of stops difference between a white card in sunlight and a black cat in the shade.

There are problems with spot meters beyond the obvious identification of what to measure from, which I've covered elsewhere (about to head to the kitchen to cook, back later - hence terse reply).

 

[Harlequin565]

Well, I suppose you could meter for the sky, and then the undergrowth and see what the difference is. Is there any reason you are using incident reading though?

This is how I did it with a spot meter. Until it became too much like hard work, and too prone to error because I'm bad at maths. Taking a spot meter reading for the subject and letting the highlights and shadows fall where they may has been my go-to since I overcomplicated it. An incident meter is great if you're near the subject, or in open diffused light but a landscape photographer standing under a tree to reduce flare and pointing at a bright skyline with a bunch of trees on the other side of a lake is going to have problems.

Film is also more forgiving than digital (in my experience) if you use a "forgiving" film. Stuff like Ferrania, or Velvia really does require a correct exposure within a stop or two, whereas stuff like HP5 can still give good results even if you get it badly wrong. It's one of the reasons I don't shoot with T grain films (TMAX, Ilford Delta etc) and also why I don't tend to shoot a lot of colour (which in my opinion is generally less forgiving than B&W)

 

[Barney]

Well, I suppose you could meter for the sky, and then the undergrowth and see what the difference is. Is there any reason you are using incident reading though?

hi Nev it is an incident light meter.
The camera does not have a meter or facility to input the film speed so light meter is a must. I think.

 

[Barney]

Are you using it as an incident meter? If so, just hold the meter in front of the subject with the dome facing the camera. You're recording incident light, which is the light falling onto the subject, not the light reflected back (as with a spot meter reading).

If the subject is further away and in different light, e.g. you're in shadow and the subject is in sunlight, then you'll need to compensate.

hi Nige that is what i am trying to do, evaluate the differences over the scene and compensate as I see fit, ie if I want details in sky or trees, how many stops difference is there?

 

[Barney]

An incident light reading is basically taking a reading from an artificial highlight (the inside of the white dome). Using the meter in the shade and in full sunlight will give you a measure of how much difference there is between full sun and shade, but won't give you an idea of the number of stops difference between a white card in sunlight and a black cat in the shade.

There are problems with spot meters beyond the obvious identification of what to measure from, which I've covered elsewhere (about to head to the kitchen to cook, back later - hence terse reply).

thanks for replying Stephen, it does not read as terse to me at all.

 

[Barney]

This is how I did it with a spot meter. Until it became too much like hard work, and too prone to error because I'm bad at maths. Taking a spot meter reading for the subject and letting the highlights and shadows fall where they may has been my go-to since I overcomplicated it. An incident meter is great if you're near the subject, or in open diffused light but a landscape photographer standing under a tree to reduce flare and pointing at a bright skyline with a bunch of trees on the other side of a lake is going to have problems.

Film is also more forgiving than digital (in my experience) if you use a "forgiving" film. Stuff like Ferrania, or Velvia really does require a correct exposure within a stop or two, whereas stuff like HP5 can still give good results even if you get it badly wrong. It's one of the reasons I don't shoot with T grain films (TMAX, Ilford Delta etc) and also why I don't tend to shoot a lot of colour (which in my opinion is generally less forgiving than B&W)

Thank you Ian,

comments noted, that is the kind of experience I don't have and is invaluable.

 

[FishyFish]

hi Nige that is what i am trying to do, evaluate the differences over the scene and compensate as I see fit, ie if I want details in sky or trees, how many stops difference is there?

The easiest way is to take a reading in similar light to the subject (assuming you can't get close to it). So, say you're taking a picture of a distant building that is in full sunlight, try to find somewhere close that is also in sunlight and take the reading there - the light will be the same. If you can't do that then you may need to start making estimates. If you have a smartphone then there are a range of light meter apps available that will take both incident and reflective readings, which can be very useful.

 

[Plain Nev]

I must admit I use the spot meter for just about everything. If I'm at all doubtful I just go to the subject, excluding the sky, and meter that way.

 

[excalibur2]

Just a small point.......For your shot it depends what's in the shadow, some shots would look better if what's in the shadow was darker.
Just AAMOI.....For many years had a problem we portraiture on a sunny day when the person was squinting with the sun in the eyes, so turning the person around into the shadow and a nice back ground (that you wanted) looked blown out, you can solve that with a flashgun but if you haven't got something like a Canon T90 with matching gun, you'll have to work out the exposure from flashgun and back ground and balance the result.
In Photoshop you can increase shadow detail if it is important providing there was enough exposure on the film.

 

[sk66]

You will note that any camera with a built in meter has a range of 5 stops. Ansel Adam's zone system uses 7 stops between the darkest and brightest levels that show any detail. Most films have a dynamic range of about 12 stops. Most photo papers have a range of about 8 stops (glossy) or less (matte). Ansel's zone system was about exposing the scene's DR for the DR of the film, adjusting the film's development, and then printing it for the DR of printing paper... thus it has 11 stops total (film) and 7 stops "usable" (paper).

It is not really possible to answer your question... "what is the exposure of a bright sky?" Directly overhead where it is most saturated, or near the horizon where it fades to white?
"What is the exposure of dark undergrowth?" On what day; with what kind of lighting?

The question you should be asking is what is the DR of the scene, what is the DR of the film you're using, and what is the DR limit of the final output... and then you place the midtones appropriately to achieve the desired result within those limits. The only difference between spot and incident metering is that with spot you are selecting midtone, and incident metering assumes midtone. The difficulty of incident metering is in knowing if the scene actually averages to midtones or not, and when to shift the exposure. And similarly, with spot metering the difficulty is in knowing what to select to be midtone (meter) if you do not want a "correct" exposure (I.e. blown out whites on a bright sunny day).

 

[Barney]

You will note that any camera with a built in meter has a range of 5 stops. Ansel Adam's zone system uses 7 stops between the darkest and brightest levels that show any detail. Most films have a dynamic range of about 12 stops. Most photo papers have a range of about 8 stops (glossy) or less (matte). Ansel's zone system was about exposing the scene's DR for the DR of the film, adjusting the film's development, and then printing it for the DR of printing paper... thus it has 11 stops total and 7 stops "usable."

It is not really possible to answer your question... "what is the exposure of a bright sky?" Directly overhead where it is most saturated, or near the horizon where it fades to white?
"What is the exposure of dark undergrowth?" On what day; with what kind of lighting?

The question you should be asking is what is the DR of the scene, what is the DR of the film you're using, and what is the DR limit of the final output... and then you place the midtones appropriately to achieve the desired result within those limits. The only difference between spot and incident metering is that with spot you are selecting midtone, and incident metering assumes midtone. The difficulty of incident metering is in knowing if the scene averages to midtones or not, and when to shift the exposure. And similarly with spot metering the difficulty is in knowing what to select to be midtone (meter) if you do not want a "correct" exposure (I.e. blown out whites on a bright sunny day).

Steven,

Thanks you for your eloquent explanation of the situation. That is the exact problem that I failed to fully identify and illustrate. Lack of terminology at my disposal.

In my digital Photography I am taking a guess at the overall DR and selecting the midpoint and spot metering on that. With, I must say, results that I am satisfied with. Correctly or otherwise.

When using film and without in camera metering, it is another kettle of fish, and it is this problem I am trying to solve.

I remember some time long ago that i used a rudimentary method for determining the flim speed required , a bright sunny day at the beach 50 a walk through a shaded woodland on the same bright day 400, The midtone incident reading on those situations can vary enormously.

I think that I am starting to understand.

 

[Nod]

However, in digital I am a great fan of the spot meter

Herein lies your answer! Find a scene with deep. dark shadows and a bright sky then take a spot meter reading from each using your digital camera. Then switch to full scene average metering (which will give a reasonable approximation of incident light) to get the average setting.

 

[Garry Edwards]

Generally, an incident reading will always be the best option, simply because it reads the light incident upon the subject (falling on the subject and not reflected from it), so the reading cannot be affected by the subject's reflective value.

Reflected readings (including spot metering) are always a compromise, and the general "rule" is to use an incident reading when possible, and to use a reflective reading only when we can't physically get to the subject to take an incident reading.

This is how I did it with a spot meter. Until it became too much like hard work, and too prone to error because I'm bad at maths. Taking a spot meter reading for the subject and letting the highlights and shadows fall where they may has been my go-to since I overcomplicated it. An incident meter is great if you're near the subject, or in open diffused light but a landscape photographer standing under a tree to reduce flare and pointing at a bright skyline with a bunch of trees on the other side of a lake is going to have problems.

Film is also more forgiving than digital (in my experience) if you use a "forgiving" film. Stuff like Ferrania, or Velvia really does require a correct exposure within a stop or two, whereas stuff like HP5 can still give good results even if you get it badly wrong. It's one of the reasons I don't shoot with T grain films (TMAX, Ilford Delta etc) and also why I don't tend to shoot a lot of colour (which in my opinion is generally less forgiving than B&W)

(My bold). Valid points, but even Velvia generally copes with the extremes pretty well. It was, after all, the tranny film of choice before digital.

 

[Terrywoodenpic]

Most of my professional life I used incident light metering.
Not exclusively but mostly.
Incident readings have the advantage of pegging tones in the image and subject to each other.
Highlights match highlights and shadows match shadows, as does every tone in-between.
However the light falling on the subject must be the same as the light falling on the dome of the meter.
To achieve this the meter must be pointed from the subject towards the camera, or the equivalent for more distant subjects.
One can have every confidence that sunlight falling on a close by subject is at the same intensity as that of a distant object.
The same is true of subjects lit by an overcast sky.

The biggest problems come when you are shooting in dappled light like in woodland. Some parts are lit but sunlight, and other parts by filtered and reflected light only.
In these situations you have two options, the first is to use your meter as a reflected light meter (most incident meters have this facility) and take general reading.
The second is to take two or more incident readings and average them, one with sunlight falling on the dome and another without.
Both these methods will give you an average reading. But one where the dynamic range is most likely far greater than your film or sensor can cope with.
Usually a choice has to be made to either favour the highlights or shadows, there is no one correct way.
If you are working in digital you can take multiple exposures and fuse them. This can capture all the tones but has two major problems the fist is subject movements and the second is the resulting image will have extremely compressed tones, and will probably look flat and uninteresting.
Usually the better choice is to expose for the main subject, however it is lit, and let the other parts do what they may.

There is one thing to understand in using exposure meters of all kinds, there is no such thing as a correct exposure, exposure is always a choice about the range of tone that you want to capture. Camera makers know this, and this is why they always give you a choice of metering methods. That, or use their fully automatic setting which makes an intelligent guess based on remarkably good algorithms.

Interesting factoid.. you can use a reflected light meter as a sort of incident light meter by pointing it at the main light source, the resulting reading will almost always be close to 4 1/2 stops different to a normal reading.

 

[excalibur2]

Most of my professional life I used incident light metering.
Not exclusively but mostly.
Incident readings have the advantage of pegging tones in the image and subject to each other.
Highlights match highlights and shadows match shadows, as does every tone in-between.
However the light falling on the subject must be the same as the light falling on the dome of the meter.
To achieve this the meter must be pointed from the subject towards the camera, or the equivalent for more distant subjects.
One can have every confidence that sunlight falling on a close by subject is at the same intensity as that of a distant object.
The same is true of subjects lit by an overcast sky.

The biggest problems come when you are shooting in dappled light like in woodland. Some parts are lit but sunlight, and other parts by filtered and reflected light only.
In these situations you have two options, the first is to use your meter as a reflected light meter (most incident meters have this facility) and take general reading.
The second is to take two or more incident readings and average them, one with sunlight falling on the dome and another without.
Both these methods will give you an average reading. But one where the dynamic range is most likely far greater than your film or sensor can cope with.
Usually a choice has to be made to either favour the highlights or shadows, there is no one correct way.
If you are working in digital you can take multiple exposures and fuse them. This can capture all the tones but has two major problems the fist is subject movements and the second is the resulting image will have extremely compressed tones, and will probably look flat and uninteresting.
Usually the better choice is to expose for the main subject, however it is lit, and let the other parts do what they may.

There is one thing to understand in using exposure meters of all kinds, there is no such thing as a correct exposure, exposure is always a choice about the range of tone that you want to capture. Camera makers know this, and this is why the always give you a choice of metering methods. That, or use their fully automatic setting which makes an intelligent guess based on remarkably good algorithms.

Interesting factoid.. you can use a reflected light meter as a sort of incident light meter by pointing it at the main light source, the resulting reading will almost always be close to 4 1/2 stops different to a normal reading.

...or just take a reflective reading (in the same light) equivalent to a Kodak grey card which could be blue sky, green grass, paving stones, roads, tree trunks etc etc..... anyway works for me.

 

[Terrywoodenpic]

...or just take a reflective reading (in the same light) equivalent to a Kodak grey card which could be blue sky, green grass, paving stones, roads, tree trunks etc etc..... anyway works for me.

Or from the front of your hand It will give a standard exposure what ever your skin colour. And you always have it with you. I did that between 1946 an 1957 before I could afford my first dedicated incident meter.

 

[StephenM]

Or from the front of your hand It will give a standard exposure what ever your skin colour. And you always have it with you. I did that between 1946 an 1957 before I could afford my first dedicated incident meter.

I still do that.

 

[excalibur2]

Or from the front of your hand It will give a standard exposure what ever your skin colour. And you always have it with you. I did that between 1946 an 1957 before I could afford my first dedicated incident meter.

IIRC the metering system on cameras was based on the Kodak grey card, as they knew joe public were going to take common shots with the camera exposure meter reading roughly the same, and the latitude of film would compensate any difference/errors.

 

[Dave Goodier]

Good Evening everyone,

I have identified another deficiency in my methodology, "oh no you haven't" I hear you all cry.

I am using a light meter and using the incident light reading for exposure. However, in digital I am a great fan of the spot meter and exposure lock facility where I mentally identify the, what appears to me, mid tone and lock up on it.

My question is that with an incident light meter how may stops difference are the between bright sky and dark undergrowth? I would like to think there is a method to calculate theses things without resort to guesswork, I need to have an element of input into the process of exposure.

Blinkies - RULE

If you have this option turn it on and enjoy easy exposure evermore

 

[Terrywoodenpic]

IIRC the metering system on cameras was based on the Kodak grey card, as they knew joe public were going to take common shots with the camera exposure meter reading roughly the same, and the latitude of film would compensate any difference/errors.

The first cameras with exposure meters were just that, cameras with exposure meters built in but not connected in any way. It was quite a lot later that they could make automatic adjustments and then only to aperture settings. How they were calibrated was mostly proprietary but based on normal sensitometric principals. No two makes gave anything like identical results. Follow needle type exposure settings ruled the scene for many years. Followed by fully electronic setting mechanisms that could set both shutters and apertures. All these early exposure systems at were limited to average exposure readings. It was not untill the digital age that comprehensive exposure algorithms came in to general use.
Prior to that the multi exposure settings available on the Olympus OM4 was the most sophisticated. This allowed the averaging of a number of spot readings to be set.

 

[Terrywoodenpic]

Blinkies - RULE

If you have this option turn it on and enjoy easy exposure evermore

That only allows you to help avoid burn out of highlights on digital cameras, it is no help at all and unavailable to film users.
The histogram is perhaps more generally useful to digital users.

 

[FishyFish]

Blinkies - RULE

If you have this option turn it on and enjoy easy exposure evermore

You might struggle to find this feature on a film camera.

 

[excalibur2]

Prior to that the multi exposure settings available on the Olympus OM4 was the most sophisticated

..and the Canon T90, as it can take 8 spot readings and average them out automatically.

 

[Terrywoodenpic]

..and the Canon T90, as it can take 8 spot readings and average them out automatically.

Came rather later.

 

[sk66]

I remember some time long ago that i used a rudimentary method for determining the flim speed required , a bright sunny day at the beach 50 a walk through a shaded woodland on the same bright day 400, The midtone incident reading on those situations can vary enormously.

Probably something like the "Sunny 16 Rule."

On a typical bright sunny day the ISO should be the inverse of the SS when the lens is set to f/16 (as close as possible). E.g. f/16, 1/100, 100. Then for every distinct change in light intensity it is ~ 2 stops less.
f/16- distinct shadows (sunny day; reflective surfaces add a stop (sand/snow/etc))
f/8- soft/minimal shadows (heavy overcast)
f/4- no shadows (shade)
Of course, you could instead trade a different factor rather than the aperture.

But this just approximates average/incident metering when you don't have a meter available (and relies on the latitude of film to some extent).

In my digital Photography I am taking a guess at the overall DR and selecting the midpoint and spot metering on that. With, I must say, results that I am satisfied with. Correctly or otherwise.

If you are selecting the midpoint of the scene's DR, and not something that should be at midpoint like pure red, then you are exposure shifting (e.g. ETTR). In this case the resulting exposure will be different from incident metering. E.g. midtones record as below mid in order to save highlights, because the scene was brighter.

To replicate that with incident metering simply find something that should be ~ mid grey and estimate how far off it appears to be... e.g. if it appears white it is ~ 2 stops brighter, or if it appears black it is ~ 2 stops darker than it should be. Then shift the metered exposure appropriately. Ignore anything that appears pure white or pure black (clipped) as there is no way to know how far over/under they are. And try not to focus on the extremes, as your eyes will adjust to that brightness.

All of this involves some guessing/approximation/error. But there isn't necessarily anything wrong with that... you might choose to shift away from the metered/correct exposure at anytime for creative reasons.

If the scene does not exceed the DR of the film being used (i.e. no pure whites or deep shadows/blacks), then there is no need to adjust the exposure away from the incident reading because the film can record all of it. And anything that is midtone within the scene will record as midtone... this does not involve guessing/error. And even if the scene does exceed the film's DR it will still look correct to how the scene actually appeared/existed (i.e. blown highlights/clipped shadows).

The next step is adjusting the darkroom exposure of the film to fit the paper if the film's exposure exceeds the paper's capability (e.g. prioritize shadows). Or to compress the darkroom exposure to fit within the paper's capability (dodge/burn).

_______________

There is another method which involves adjusting the film's exposure and development time in order to fit more of a scene's DR into the film's capability E.g. Pulling the exposure (overexposure and under development) results in a flatter negative with less contrast; suitable for brighter conditions/scenes. But I never messed around with this much as I almost always used roll film and you need to push or pull the whole roll. The results are also rather particular to the film being used and not so useful with color... (this is the other part of Ansel's Zone System.)

 

[Terrywoodenpic]

Probably something like the "Sunny 16 Rule."

On a typical bright sunny day the ISO should be the inverse of the SS when the lens is set to f/16 (as close as possible). E.g. f/16, 1/100, 100. Then for every distinct change in light intensity it is ~ 2 stops less.
f/16- distinct shadows (sunny day; reflective surfaces add a stop (sand/snow/etc))
f/8- soft/minimal shadows (heavy overcast)
f/4- no shadows (shade)
Of course, you could instead trade a different factor rather than the aperture.

But this just approximates average/incident metering when you don't have a meter available (and relies on the latitude of film to some extent).


If you are selecting the midpoint of the scene's DR, and not something that should be at midpoint like pure red, then you are exposure shifting (e.g. ETTR). In this case the resulting exposure will be different from incident metering. E.g. midtones record as below mid in order to save highlights, because the scene was brighter.

To replicate that with incident metering simply find something that should be ~ mid grey and estimate how far off it appears to be... e.g. if it appears white it is ~ 2 stops brighter, or if it appears black it is ~ 2 stops darker than it should be. Then shift the metered exposure appropriately. Ignore anything that appears pure white or pure black (clipped) as there is no way to know how far over/under they are. And try not to focus on the extremes, as your eyes will adjust to that brightness.

All of this involves some guessing/approximation/error. But there isn't necessarily anything wrong with that... you might choose to shift away from the metered/correct exposure at anytime for creative reasons.

If the scene does not exceed the DR of the film being used (i.e. no pure whites or deep shadows/blacks), then there is no need to adjust the exposure away from the incident reading because the film can record all of it. And anything that is midtone within the scene will record as midtone... this does not involve guessing/error. And even if the scene does exceed the film's DR it will still look correct to how the scene actually appeared/existed (i.e. blown highlights/clipped shadows).

The next step is adjusting the darkroom exposure of the film to fit the paper if the film's exposure exceeds the paper's capability (e.g. prioritize shadows). Or to compress the darkroom exposure to fit within the paper's capability (dodge/burn).

_______________

There is another method which involves adjusting the film's exposure and development time in order to fit more of a scene's DR into the film's capability E.g. Pulling the exposure (overexposure and under development) results in a flatter negative with less contrast; suitable for brighter conditions/scenes. But I never messed around with this much as I almost always used roll film and you need to push or pull the whole roll. The results are also rather particular to the film being used and not so useful with color... (this is the other part of Ansel's Zone System.)

Film manufacturers like Kodak used to supply data sheets for all their film . These included processing time and resulting gamma (contrast) with this you could work out the dev time needed for any brightness range. Except for a few standard gammas, no one except for even fewer nerds, ever did this. Or some, like me, tried it, made it work , and decided it was not worth the hassle. So stuck to a few known development times. At that time I was almost exclusively working in large format.
But unlike Ansel Adams I was not prepared to make copious notes about exposures and processing for every individual shot and piece of film stock.

Most of us established film speed ratings exposures and development times, that we knew would produce the necessary density and contrast, that would print on grade 2 paper on our enlargers, either cold cathode (soft light) or condenser (hard light).

When colour came along things became even easier with fewer options, over time processes changed but standardisation was key. Though colour balance was critical.
Some people could colour grade others could not. Professional colour labs soon became the norm. Standardisation became even more important for best results.
When every thing became easy and second nature digital came along. Soon. We found everything wass much the same as always, but in many ways easier still and better.

 

[sk66]

Film manufacturers like Kodak used to supply data sheets for all their film . These included processing time and resulting gamma (contrast) with this you could work out the dev time needed for any brightness range. Except for a few standard gammas, no one except for even fewer nerds, ever did this. Or some, like me, tried it, made it work , and decided it was not worth the hassle. So stuck to a few known development times. At that time I was almost exclusively working in large format.
But unlike Ansel Adams I was not prepared to make copious notes about exposures and processing for every individual shot and piece of film stock.

Most of us established film speed ratings exposures and development times, that we knew would produce the necessary density and contrast, that would print on grade 2 paper on our enlargers, either cold cathode (soft light) or condenser (hard light).

When colour came along things became even easier with fewer options, over time processes changed but standardisation was key. Though colour balance was critical.
Some people could colour grade others could not. Professional colour labs soon became the norm. Standardisation became even more important for best results.
When every thing became easy and second nature digital came along. Soon. We found everything wass much the same as always, but in many ways easier still and better.

I have next to zero LF experience, minimal MF, and it's been about two decades since I've messed with film at all.
This kind of information/knowledge is becoming pretty arcane these days...

 

[Terrywoodenpic]

I have next to zero LF experience, minimal MF, and it's been about two decades since I've messed with film at all.
This kind of information/knowledge is becoming pretty arcane these days...

Absolutely.
I would never go back to film again, though I can understand people wanting to try it.
However the full ecosystem no longer exists, and the internet is full of misinformation
to waylay those looking to learn.

However those of us with a background in film had a head start when it came to working in digital.
It is in some respects the painting by numbers version of photography, in terms of deskilling.
But in most respects it can produce far better technical results with less effort and expense.

Photography has never been cheaper, taking inflation into account.

 

[droj]

Or from the front of your hand

Yeah, I used to do that a lot with transparency. Or evenly-lit grass, or a clear blue sky, or what I felt was mid-toned clothing. Other gambits were reflective metering a snowy landscape & opening up 2 stops. Incident isn't always relevant to landscape because of lighting differences with distance.

Exposure principles remain the same as ever, though digital equates to slide film, rather than neg film where you might read from the shadows depending on your methodology, & how you rated your film would have to factor into that.

With mirrorless in particular, I've become a devotee of the in-EVF histogram. Plus the huge flexibilty of RAW processing, as long as you've protected your highlights to start with and are using a modern body with lots of low-noise shadow grunt.

 

[excalibur2]

Photography has never been cheaper, taking inflation into account

Well maybe comparing to the 60's e.g. Kodachrome was very expensive and if it was available today with inflation would be about £36 per roll. When the machinery, workforce etc advanced to mass produce film, there was a time for joe public when you sent your film off to be dev and printed and you got a free film back.
And not forgetting Poundland film for £1...which were Fuji and even Kodak Ultra was being sold, Ok it might be the clearance of film (maybe the same reason for the cost of film 5 or 6 years ago for other film) because of the digi revolution but still a shock when once for a time you could buy cheap film and now you can't.

 

[PeterSpencer]

Probably something like the "Sunny 16 Rule."

On a typical bright sunny day the ISO should be the inverse of the SS when the lens is set to f/16 (as close as possible). E.g. f/16, 1/100, 100. Then for every distinct change in light intensity it is ~ 2 stops less.
f/16- distinct shadows (sunny day; reflective surfaces add a stop (sand/snow/etc))
f/8- soft/minimal shadows (heavy overcast)
f/4- no shadows (shade)
Of course, you could instead trade a different factor rather than the aperture.

But this just approximates average/incident metering when you don't have a meter available (and relies on the latitude of film to some extent).


If you are selecting the midpoint of the scene's DR, and not something that should be at midpoint like pure red, then you are exposure shifting (e.g. ETTR). In this case the resulting exposure will be different from incident metering. E.g. midtones record as below mid in order to save highlights, because the scene was brighter.

To replicate that with incident metering simply find something that should be ~ mid grey and estimate how far off it appears to be... e.g. if it appears white it is ~ 2 stops brighter, or if it appears black it is ~ 2 stops darker than it should be. Then shift the metered exposure appropriately. Ignore anything that appears pure white or pure black (clipped) as there is no way to know how far over/under they are. And try not to focus on the extremes, as your eyes will adjust to that brightness.

All of this involves some guessing/approximation/error. But there isn't necessarily anything wrong with that... you might choose to shift away from the metered/correct exposure at anytime for creative reasons.

If the scene does not exceed the DR of the film being used (i.e. no pure whites or deep shadows/blacks), then there is no need to adjust the exposure away from the incident reading because the film can record all of it. And anything that is midtone within the scene will record as midtone... this does not involve guessing/error. And even if the scene does exceed the film's DR it will still look correct to how the scene actually appeared/existed (i.e. blown highlights/clipped shadows).

The next step is adjusting the darkroom exposure of the film to fit the paper if the film's exposure exceeds the paper's capability (e.g. prioritize shadows). Or to compress the darkroom exposure to fit within the paper's capability (dodge/burn).

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There is another method which involves adjusting the film's exposure and development time in order to fit more of a scene's DR into the film's capability E.g. Pulling the exposure (overexposure and under development) results in a flatter negative with less contrast; suitable for brighter conditions/scenes. But I never messed around with this much as I almost always used roll film and you need to push or pull the whole roll. The results are also rather particular to the film being used and not so useful with color... (this is the other part of Ansel's Zone System.)

I've found an alternative 'Sunny 11 rule' to be more reliable here in the North. It seems to be nearer to incident readings, in my experience. Also if you are using negative film it adds a little bit of a safety net.

 

[PeterSpencer]

I just checked using my Sekonic outside, 20 miles south of Berwick, with a clear sky and bright sun. 1/125 at f11.

 

[Barney]

More or less same conditions here

F 11.5 in full sun (at .5 suggestion is to go to the next stop)
F 4.01 in the shade

 

[sk66]

More or less same conditions here

F 11.5 in full sun (at .5 suggestion is to go to the next stop)
F 4.01 in the shade

That correlates with the f/16 and f/4 of the sunny 16 rule. As Peter noted, slight overexposure (f/11) is safer/better with negative film, but slight underexposure (f/16) is better with positive film (slides).

Interestingly, an EV (light intensity) of 15 correlates to the sunny 16 rule at f/16... and EV values closely correlate at different exposures as well (2 stops = 2 EV)... you could pretty easily use an EV chart to determine any suitable combination of exposures (close enough)...

 

[sk66]

I've found an alternative 'Sunny 11 rule' to be more reliable here in the North. It seems to be nearer to incident readings, in my experience. Also if you are using negative film it adds a little bit of a safety net.

It's not really surprising... there isn't really a universal standard for light meters. And any standard that is applied still allows for an accuracy/calibration tolerance (e.g. ISO 2720-1974). But how much difference does a half stop, or even a full stop make really? I.e. with slide film the "correct exposure" was never at the rated ISO/ASA...