Creative control over exposure

[bmattock]

Any given film or sensor has a latitude or exposure range. It will record an image from a certain low light level to a certain low light level. Anything below the range it can capture will be lost, and so will anything above that range. In order to take creative control over exposure, one must know what that latitude range is in f-stops.

Many scenes one might wish to photograph go well beyond the boundaries of our film or sensor. Thus, every photograph taken in such circumstances is a compromise regarding exposure. One either sacrifices detail at the brightest end or the darkest, or both.

Exposure meters in cameras are intended to give readings which will generally give 'acceptable' results, and they often do. Hand-held meters work the same way, either reflective or incident (I'm ignoring flash meters for the purposes of this posting). Spot meters are a type of reflective meter that allow precise metering of a very selective area of the scene, typically one degree.

A spot meter allows a photographer to measure the darkest and the lightest parts of the scene. The meter will give a light reading for both. Using either reading will result in a 'correct' exposure (meaning middle-tone grey) for either the darkest of the lightest part of the scene, but that is generally not what we want. Therefore, one must extrapolate and visualize what one wishes to achieve, and derive a exposure setting that captures one's intent.

People often complain that meters are 'wrong' about exposure. Meters that work correctly are not 'wrong'. But neither are they intelligent. They meter the light which strikes them. Many cameras have computers in them which calculate exposure based upon complex algorithms that represent what 'normally works' given a certain type of scene, or they do (older cameras) weight-based averaging. They often do a fine job, but they are still guessing. When they guess wrong, we say that the meter messed up. They did in the sense that we did not get what we wanted to get, but they did not mess up in the sense that they measured the light accurately, but interpreted the data incorrectly. The only way to ensure interpreting the data correctly is to do the metering oneself. And precise meter readings require a spotmeter.

Take a meter reading of your scene's darkest area. Take a meter reading of the lightest area. Decide where you want the darkest area that still contains detail to be on your photograph, as well as the lightest. Determine if the film or sensor you are using is capable of encompassing both the lightest and the darkest areas, and if not, decide how you wish to apply the compromise (which area you wish to lose detail in, dark, light, or both; and how much). Apply that setting to your camera and take the photograph.

This method is not best for every photograph one might take. It requires time and effort and it is not extremely quick, although with practice it does become reasonably rapid. It is not necessary except when one wishes to practice precise exposure control for creative effect.

 

[David William White]

Good and true: Automated metering systems can't know what you find interesting. Alas, I don't have a spotmeter, so I'll only say I think I prefer center-weighted systems over 'matrix' when I'm using the TTL meter because I can aim at what I choose for mid-grey, lock exposure, then recompose. But yes, it's not 'point and shoot'.

Also, if your shooting rollfilm, you can and should bracket your important or tricky shots. Doing so, and seeing the results on your contact sheet will also give you great insight into your metering system and what it is capable of doing.

I should also like to add that properly developed black and white film has 10, maybe 12 stops of latitude, and it's surprising what detail can be found in a negative at either end. Seems paper can only handle about 5 stops via straight printing, but with split-grade printing, a couple of more stops can be wrung out of it.

D.

 

[Roger Hicks]

A spot meter allows a photographer to measure the darkest and the lightest parts of the scene. The meter will give a light reading for both. Using either reading will result in a 'correct' exposure (meaning middle-tone grey) for either the darkest of the lightest part of the scene, but that is generally not what we want. Therefore, one must extrapolate and visualize what one wishes to achieve, and derive a exposure setting that captures one's intent.

Dear Bill,

No it won't. At least, it won't as long as you have the faintest idea how to use a spot meter.

All properly designed spot meters have both shadow and highlight indices. Using the shadow index will key exposure to the shadows, i.e. ensure that you have enough information in the shadows (and damn the highlights). This is almost always all you need for negatives. Using the highlight index will key exposure to the highlights, i.e. ensure that they will not 'blow', and damn the shadows. This is almost always all you need for transparency and digital.

I am sure you know this but your post might mislead others. A 'mid-tone' index on a spot meter is substantially worthless, which is why the world's first successful spot meter, the SEI, didn't even have one. As far as I can see, mid-tone indices started to become popular when spot meters started to be used by people who ddn't know what they were doing, and who were were taken in by the poisonous mythology of the 18% grey card.

Cheers,

R.

 

[Pickett Wilson]

Given the limitations of slide film, especially Kodachrome, I decided that the reason NatGeo photographers spent months on projects in the past was because to get those amazingly well lit photos they only shot on overcast days!

You can see a photographer struggling with the exposure range, and using it artistically, by looking at David Allan Harvey's stuff. He had to meter for the highlights (he shot Kodachrome for years), which dropped the shadows to pitch black. But he used it effectively to convey his vision.

 

[ferider]

Instead of using a spot meter, Bill's method is made easier with meters (like most Gossen digital meters) that can show you a varying contrast range while you measure. For me at least. You can then visualize the scene's dynamic range and quickly pick a setting, without arithmetic gymnastics.

 

[David William White]

...the poisonous mythology of the 18% grey card...

This sounds like it needs an essay, Roger. Can you favour us?

 

[Igor.Burshteyn]

What Roger says (it's hard to argue with "Perfect Exposure" author). Camera that I use most (Oly OM4ti) allows one-click compensation for highlights or shadows, as well as brightness range measurement. Pentax Digital Spot Meter (in use with meter-less cameras), has IRE index and manual that describes highlights/shadows metering techniques.

 

[degruyl]

All properly designed spot meters have both shadow and highlight indices. Using the shadow index will key exposure to the shadows, i.e. ensure that you have enough information in the shadows (and damn the highlights). This is almost always all you need for negatives. Using the highlight index will key exposure to the highlights, i.e. ensure that they will not 'blow', and damn the shadows. This is almost always all you need for transparency and digital.

Ok, you have a spot reading either light point not blown or dark point with detail. How many levels do you move that to get to an exposure? Do you vary this by film? Even if you are using the zone system, do you rate this zone 2/8, or 1/9? (In other words, do you move the reading three stops or four?)

Note: these are actually serious questions. I can just about wrap my head around the zone system, but using a single point measurement to determine exposure requires a decision based on how much latitude the film has, right? I (obviously) have little experience with spot meters, at least good experience. I have nothing against them, just not much success.

To me, it seems easier to take a center meter reading, and adjust for what I am trying to do with the scene. It might not be better, but it works pretty well for me.

 

[Sparrow]

What format are we talking about here?

 

[Pickett Wilson]

Degruly, Actually, there are two parts to the Zone system, if you are talking about the system Adams advocated. One is exposure, the other development. You manipulate both to place the zones where you want them. Which may be the reason you are having trouble with the concept.

 

[Al Kaplan]

I much prefer to read the light illuminating the subject. A fast incident reading, in a few places around the scene if time allows, and start shooting.

If you want to be a real nit picker then you're going to have to get all of the shutter speeds on all of your bodies callibrated, the same for your meter(s), and get your lenses T-stopped. Then depending on age and storage conditions, both before and after exposure, you'll have to run tests on the true speed of the actual batch of Tri-X that you'll be using. I don't have time for all that. I was taught that if you have lousy negatives you need to become more skilled at printing.

 

[degruyl]

Technically, I am not having trouble. I am just not using it. My question was about Roger's method and where he places the shadows / highlights.

That being said: I know what you are saying. Only, with roll film you can't adjust the development unless all your frames are the same conditions. This is doable with 120 (10 frames of the same subject). Unlikely but doable. Very unlikely for 220 or 35mm, unless you are one of those people who uses a roll for a subject.

For me, exposing for the midtone works well enough. My problems with spot meters have always been with the location of the spot (built in meter: spot is misaligned). I would prefer to have more control, but I doubt that I will be carrying around a spot meter. (Unless I get a Pocket Spot. I have been looking into that for a while, but production issues...).

 

[degruyl]

I was taught that if you have lousy negatives you need to become more skilled at printing.

Which makes even more sense if you are using a digital workflow. You can do a lot with contrast and exposure in the computer, quickly and easily.

So long as the information is on the negative, it can be brought out in printing or scanning. I believe we are discussing getting the information on the negative. I might be wrong, though. I appear to have misunderstood something, in this thread.

 

[Yammerman]

All properly designed spot meters have both shadow and highlight indices. Using the shadow index will key exposure to the shadows, i.e. ensure that you have enough information in the shadows (and damn the highlights). This is almost always all you need for negatives. Using the highlight index will key exposure to the highlights, i.e. ensure that they will not 'blow', and damn the shadows. This is almost always all you need for transparency and digital.

Just to clarify. I use a Sekonic L558 which has a spot meter option. It does not have the indices you describe but I simply set the ISO 2 stops higher than the film i'm using and measure the shadows where I require detail. This seemed to work for me so is this what the indices do or have I completely misunderstood?

 

[bmattock]

Just to clarify. I use a Sekonic L558 which has a spot meter option. It does not have the indices you describe but I simply set the ISO 2 stops higher than the film i'm using and measure the shadows where I require detail. This seemed to work for me so is this what the indices do or have I completely misunderstood?

I use the L358 with the optional attached spot-meter. It does not have the indices Roger refers to. However, the Minolta Spot Meter F does. This is a bias option that allows one to measure, for example, the darkest area of the scene and inform the meter that it is 'dark'. It will then give a meter reading that will ensure that this area remains dark and will not give it a meter reading that would normally expose it for middle tone grey (which it is not, obviously).

The problem Roger is referring to is that spot meters do not know what they are being pointed at, and they 'assume' that you want to 'correctly' expose whatever it is you are measuring; that is, unless you tell it that "this is a highlight" or "this is a shadow" and then it sets an exposure bias appropriately.

However, this type of biasing is just math. You can do it yourself with ease. Nothing magical going on there.

 

[bmattock]

All properly designed spot meters have both shadow and highlight indices. Using the shadow index will key exposure to the shadows, i.e. ensure that you have enough information in the shadows (and damn the highlights). This is almost always all you need for negatives. Using the highlight index will key exposure to the highlights, i.e. ensure that they will not 'blow', and damn the shadows. This is almost always all you need for transparency and digital.

You are presuming that what I intend is a conventional 'correct' exposure. That is, some shadow detail in all but the darkest part of the scene, and wherever the highlights blow out on the top end is fine. I agree that this is commonly used and if that is what one wants, I have no argument with it.

However, in my opinion, exposure is a more capable tool than that. I consider 'proper' exposure to be whatever I wish it to be, as long as I achieve my intent.

I came to this discovery while trying to understand what it was that I found both intriguing and powerful about photographs by people such as Meatyard. I finally twigged to the fact that he was doing something I had not see before. He was a photographer in the conventional sense, and he certainly had a, shall we say, unique perspective on communicating his ideas. But more than that, he had what appeared at first glance to be a rather casual relationship with both focus and exposure. It was almost as if he did not particularly care if his photographs were 'correctly' exposed (and focused) or not. One might as well have imagined seeing a thumb stuck over his lens from time to time, for the seeming lackadaisical attitude his photos appeared to display.

It was not until thinking about it for some time that I began to realize that his use of exposure (and focus) was being used as a creative tool in his palette. Almost like when painters begin to make use of not just color and composition and canvas and brush size and so on, but also begin to play with things like texture of the paint itself. Like an actor 'breaking the fourth wall'.

It makes perfect sense now that I think about it. One controls focus for effect, and we certainly know how to control exposure as it relates to the subject matter; a certain shutter speed for action photos, running water frozen or made smooth and creamy, etc, etc. We also, from time to time, run into photographers who have intentionally made use of high key and low key effects. But this is rudimentary. Taking creative control of exposure allows much more than that, and in more subtle ways.

To do this, however, we need to be very intentional about where we place the darkest part of our scenes, and the lightest. Perhaps we want to do the usual and compensate for shadows and let the highlights go where they may - or perhaps not. Knowing where the darkest and lightest parts of the scene are with regard to exposure is therefore important for this purpose. If the darkest part of the scene is incorrectly measured as middle tone gray, and the lightest part of the scene likewise, it is of little consequence, as we're only setting stakes in the ground to use as boundaries. We are manipulating the range of the film or sensor's latitude against the actual highlights and shadows in the scene, not trying to fit the bottom and then let the top go where it will - at least, in my description of this method.

 

[bmattock]

So long as the information is on the negative, it can be brought out in printing or scanning. I believe we are discussing getting the information on the negative. I might be wrong, though. I appear to have misunderstood something, in this thread.

You understand my intent correctly. One can do a great deal of 'repair' with development, and perhaps even more with scanners and subsequent photo editing tools. This gives great latitude (pardon the pun) that was never present before, when master printing skills were required to get the most out of a negative onto an enlargement.

I am indeed referring to getting the information recorded onto the negative (or digital sensor). Information that is not recorded cannot be reclaimed, as anyone who has tried to manipulate a JPG with as much alacrity as a RAW file surely knows. So I am trying to get control over what goes onto the negative. Once I have that, I still have the full range of development, scanning, and photo editing tools available, of course.

If we assume that a given scene has more dynamic range than the media we are recording it has, we have compromises to make. There have been more-or-less standard canned compromises developed over the years that generally work well and are considered acceptable. What I am pointing out is that we can (if we wish) take considerably more control over what gets recorded onto the negative than that. We can, without a lot of effort, decide to key our exposure to fit the shadows, as Roger mentioned, or to the highlights. More importantly, we can key our exposure anywhere in-between, deciding where we wish to lose information and where we wish to keep it with a bit more precise control.

 

[bmattock]

What Roger says (it's hard to argue with "Perfect Exposure" author). Camera that I use most (Oly OM4ti) allows one-click compensation for highlights or shadows, as well as brightness range measurement. Pentax Digital Spot Meter (in use with meter-less cameras), has IRE index and manual that describes highlights/shadows metering techniques.

There is nothing wrong with what Roger says if one wants an exposure that is commonly accepted as 'correct'. What I am saying is that this may be acceptable and it may be what you want, but that is not the same as saying it is under your creative control. Perfect conventional exposure is aiming for the center of the target and hitting it. Creatively-controlled exposure is hitting anywhere on the target you choose, because you know where the edges of the target are, not just the bullseye. Both are valid approaches; the question is what you want to achieve.

 

[bmattock]

You can see a photographer struggling with the exposure range, and using it artistically, by looking at David Allan Harvey's stuff. He had to meter for the highlights (he shot Kodachrome for years), which dropped the shadows to pitch black. But he used it effectively to convey his vision.

Thanks, I will look for his stuff. Have not been acquainted with it.

 

[Mack]

We can, without a lot of effort, decide to key our exposure to fit the shadows, as Roger mentioned, or to the highlights. More importantly, we can key our exposure anywhere in-between, deciding where we wish to lose information and where we wish to keep it with a bit more precise control.

I guess that Roger's method is more of a "fail-safe" device, basic beginners stuff to get you a "usable" negative.

I agree more with your way of thinking. Myself, I like to have lots of dark areas in my prints, really deep blacks. I think this is more how I see things in reality.

For example:
When I walk into a dark room it's not the highlights that are blown, it's the shadows that disappear completely, I can't see where I'm walking.