Why can't I use incident for true black and whit with close ups portraits?

[markbarendt]

I find what 2F/2F says very convincing. Just to visualize it, imagine a portrait where the main light is a very lateral one (going by heart, Churchill's portrait by Karsh). Pointing the dome at the camera would bring overexposure. One does not want to "average" light and shadow, but to expose for light and then devise and use shadows to give more or less volume, "drama" etc. to the subject, so it is the main light that should drive the exposure.

Yes, let's visualize it.

Rule number one with light meters is to always remember that regardless of what is measured the meter always displays a reading that should place that measured brightness as middle grey.

By pointing the incident meter at the source light you are choosing to measure something closer to highlight placement, as you might with a spot meter.

Pointing an incident meter at the source rather than the camera will provide a reading that creates an underexposure.

The only real exception to this rule is for sources like ring lights that are directly in line with the camera lens axis.

 

[Thomas Bertilsson]

An incident meter will always take an average of what its sensor sees. Ideally that should be the same as what the camera lens sees. It's the intended use of that type of meter.

Now, what you do with that reading is something else entirely. You can intentionally over-expose or under-expose your film, and you can intentionally under-develop and over-develop it too.

I use the incident meter always with the dome pointed to the camera. Like Mark says, if I point it to the light source, you will not average what the camera sees, and it will not be consistent. Brightness range varies from scene to scene to scene, the light source could be of varying strength. The only consistent way of using the incident meter is to point it towards the camera to get an AVERAGE of what the camera lens sees.

I'm sure that there are other ways than my way to use the meter, and I'm not saying it's wrong to do so. But, I wouldn't want to try to keep track of brightness range of varying lighting scenarios with an incident meter. I was sure that that was what spot meters are for...

- Thomas

 

[Lee L]

Sources I have at hand that say point the incident meter at the camera from the subject position (or along a parallel axis in the same light):

Gossen, Sekonic, and Minolta incident meter instructions, i.e. the people who design and manufacture the meters. (They also say to use a flat disc for metering lighting ratios while pointed at the light, but the dome pointed at the camera for the full exposure reading for 3D objects. And use the flat disc for photographing flat art.)

Six well-known and well-respected photography manuals: Vestal, Adams, Davis, London & Upton, Horenstein, and the Leica Manual.

So that's about nine for 'point at the camera'. As I said earlier, all the dozen or so studios I worked in pointed at the camera when metering for the exposure. (At the light source for measuring lighting ratios.)

Sources (besides Collins and acolytes on the internet) that I have seen that say always point the meter at the light:

Zero.

The dome of an incident meter is a 'model' of a 3D subject. The reason it's pointed at the camera is so that it simulates the 180 degree portion of the subject that the camera can see, thereby reading the light incident on what the camera can see. If you point the meter off the axis toward the camera, you're metering stuff the camera can't see. Going off axis a little bit doesn't often change the reading enough for you to notice on film.

There are obviously times when metering with an incident meter won't work well this way. Say I had a backlit white scrim with no source of light on the camera side. I wouldn't get a proper exposure for the scrim if I incident metered from the camera side with the dome pointed at the camera. Both incident and reflected meters need an operative brain to get consistently proper exposures.

As always, you're free to use your equipment in any way you want. But it does pay in the long run to understand its design. As the unix guys say, RTFM.

Lee

P.S. It's apparent that a member of my very short ignore list is now in this thread, so this is my last post here since I'm not reading everything.

 

[Diapositivo]

Rule number one with light meters is to always remember that regardless of what is measured the meter always displays a reading that should place that measured brightness as middle grey.

By pointing the incident meter at the source light you are choosing to measure something closer to highlight placement, as you might with a spot meter.

[...]

Don't completely agree if I get right what you mean (maybe I don't get it right though).

With an incident meter you get an exposure value that is supposed to be right both if the subject is dark or is bright. (This is probably not perfectly true at the "extremes" of pure white and pure black which made the OP raise the question, but that's irrelevant now).

The incident meter give you a value that will have the bright (more reflective) appear bright and the dark (less reflective) appear dark with that light condition. The bright details will appear bright because they actually reflect more.

With an incident light meter, if there is a middle-grey subject you should have it as middle-grey, but if the subject is darker (portrait of a black man for instance) or brighter (portrait of a pale white man, for instance) you will have the same reading and you don't need to "place" zones.

The incident meter will not give you a reading that renders a certain subject as middle grey but a reading such as a middle-grey subject will be rendered as middle grey, and a bright subject will be rendered as bright, and a dark one as dark.

Only when using a reflected light meter you have to keep in mind that what is measured (not necessarily middle grey) will be rendered as middle grey.

Hope this is not a too pedantic post

Fabrizio

EDIT The point 2F/2F raises is that if the lighting ratio is low (similar lights) an average makes no damage, if the lighting ratio is high (quite different lights) an "average" will might lead to blown highlights. One controls the highlights with the exposure (pointing the lightmeter to the light source so as not to blow them) and the contrast with the management of secondary light. I find this to be perfectly reasonable and maybe this is also what Mark meant.

 

[markbarendt]

Incident meters are designed to measure the light that the camera will be able to see and give you a camera setting, to do that you have to point the dome at the lens. If there was a gray card in the scene it should expose as expected at zone 5. Skin tones, any, should fall appropriately also.

When you point the dome a different direction all bets are off.

Having the highlights blow is a different problem. You may want to measure that so that you can decide how to develop the film but in most cases with negatives, that's not a big concern.

 

[MattKing]

Most of the discussion here is about which way one should point the incident meter - toward the camera, or toward the source of the light.

There is another issue that arises with incident meters - where should the meter be when one decides where to point it.

If the subject is illuminated by multiple sources of light, and there is no part of the subject that receives light from all or the most important sources, than the averaging dome may not provide enough information to the photographer to permit the photographer to rely on a single reading. In that circumstance, it is necessary to read the light from each source, and to do more work.

If, however, the light sources tend to supplement each other (e.g. a 2 light setup including a wide fill plus a main light on one side of the face) then a single reading from a portion of the subject that is illuminated by both lights will work great with the averaging dome pointed toward the camera.

Even then, if one has something like a hair light or a separately lighted background it is important to take a reading from them, to make sure that they don't overpower the main plus fill (or are bright enough to have useful effect).

 

[Andrew Moxom]

sigh... Like the Nike commercial goes..... JUST DO IT!.. .Like many others, I use Incident metering almost all the time, and I point the meter back at the camera...I am amazed at the confusion of what is really an 'average' metering system that meters what the camera sees, not what is reflected back from your subject. It gets more complex for studio work with multiple light sources, but again the main light is what you meter for. Like any exposure, if you are doing close up work, there will likely be some adjustment requiring more exposure.

That said, ALL meters are different, ALL shutters are different, YMMV, you will need to work up tests for your own camera/lens/meter/film/development combination...

 

[CGW]

sigh... Like the Nike commercial goes..... JUST DO IT!.. .Like many others, I use Incident metering almost all the time, and I point the meter back at the camera...I am amazed at the confusion of what is really an 'average' metering system that meters what the camera sees, not what is reflected back from your subject. It gets more complex for studio work with multiple light sources, but again the main light is what you meter for. Like any exposure, if you are doing close up work, there will likely be some adjustment requiring more exposure.

That said, ALL meters are different, ALL shutters are different, YMMV, you will need to work up tests for your own camera/lens/meter/film/development combination...

Amen. Be sure to bring a friend with a DSLR, too.

 

[MaximusM3]

Amen. Be sure to bring a friend with a DSLR, too.

That's cheating but it works. Andrew has it right though..and, when in doubt, the magic word is..BRACKET.

 

[aluncrockford]

Though I am sure I know nothing, the time honoured way in studios I have worked in, is point the incident meter at the camera from the subject , then adjust the lighting output of the other lights to balance the lighting to get the effect you want, pointing the meter at the light will not be accurate as it fails to account for the fall of of the light, it is also worth noting that when using flash you nearly always drift the light across the subject and not just point it at the item you want to light ,hence pointing the dome at the camera . Though the other way of working out the light is to look at the flash output and test by instant film or shooting digital and looking at the histogram

 

[Sirius Glass]

Collins is most correct, and it is a damned shame that so many will unbudgingly argue otherwise without even thinking about it, because it is what they have always been told and what they have always done./QUOTE]

Listen to Collins and 2F/2F. Aim the meter at the camera. That is how it was designed. Aiming at the light source will give you a reading, but that reading is useless.

When all else fails, read the manual!

Steve

 

[2F/2F]

If you want to average the light falling on a plane running through the subject that is parallel to the film plane, then point the dome at the camera.

But why and how often would you actually want to do this as a matter of course?

Yes; instruction manuals say to point the meter at the camera. What a handicap and a disservice! Sometimes it takes a thinking and constantly working independent user in the field to figure out how to use something to its best benefit, not a designer. Collins was not the first to figure out the best way to use an incident meter, and he is certainly not the only one who uses them that way. Everyone who has ever taught me anything worth knowing about metering has said the same. It is certainly how incident meter use is taught at the Art Center College of Design, perhaps the most well-renowned commercial photography school in the nation, for one.

I'd just suggest that anyone who is curious shoots the six test shots I mentioned. Then make up your mind about what to do based on those shots. If you always shoot negative film, metering down the middle won't kill you, though it is not ideal. Most people don't notice, and if they do, most people actually think that slightly overexposed negs look good, so think nothing of it. As I said, it ain't a big deal with negs...though I still like to have my ideal exposure when possible. But shoot this way on positive materials and you are hurting yourself.

If you want to average main and fill, meter down the middle, of course! But think about why you want to do that first. What averaging does is to compromise between two ideal exposures for two respective parts of the image. It gets a printable neg in most situations. But if you want to preserve the lighting ratio that exists at the scene without overexposing, especially important when shooting positives, you meter the brightest light that is illuminating the part of the subject for which you want to expose.

If you don't like what metering the brightest side does to the subject, then you probably aren't properly visualizing what the ratio of light you are shooting will look like on film. Doing so will give you an accurate exposure for the most-lit part of the subject, while causing the less lit parts to fall where they ought to fall. If you are shooting in contrasty light, you should know how your film will react to that, and expect a contrasty picture. The exposure is not wrong if it has too much contrast when shot in contrasty light. It is absolutely correct, within the limits of the film when exposed and processed normally. If you don't like it, i.e. if you want to alter the ratio that is there, and capture something different on the film, that is when you use exposure and development changes, or perhaps take an averaged reading to give you some wiggle room in printing. Just because you are using an incident meter does not mean you are "stuck" with what you've got. That is not what I am saying.

 

[2F/2F]

Pointing an incident meter at the source rather than the camera will provide a reading that creates an underexposure.

The big reason we use incident meters is because they do not do that! That is what reflected meters do. Pointing an incident meter at the main light source will make mid-toned things midtones, dark things dark, and light things light when we make a normal print.

 

[markbarendt]

If you want to average the light falling on a plane running through the subject that is parallel to the film plane, then point the dome at the camera.

But why and how often would you actually want to do this as a matter of course?

Well, actually for me, almost always.

The basic job of my light meters is to find/create a reference point in the scene that I know will fall at a certain point on the film.

It is that simple.

Yes; instruction manuals say to point the meter at the camera. What a handicap and a disservice! Sometimes it takes a thinking and constantly working independent user in the field to figure out how to use something to its best benefit, not a designer.

But think about why you want to do that first. What averaging does is to compromise between two ideal exposures for two respective parts of the image. It gets a printable neg in most situations. But if you want to preserve the lighting ratio that exists at the scene without overexposing, especially important when shooting positives, you meter the brightest light that is illuminating the part of the subject for which you want to expose.

Absolutely, thinking is important, looking at a reference point for highlights can be important part of making good decisions.

Transferring a direct reading of the main light to the camera isn't a silver bullet, it's a short cut based on personal experiences and biases.

If you don't like what metering the brightest side does to the subject, then you probably aren't properly visualizing what the ratio of light you are shooting will look like on film.

I disagree.

While it is very possible to mis-understand what a given lighting ratio will give you, the relationship between the meter and the film, when the meter is used in the classic manner is very, very predictable.

When an incident meter is used in a non-classic manner many new variables are introduced. The size of the source light being one, what else will the meter be seeing once it is turned off the axis of the lens?

 

[markbarendt]

The big reason we use incident meters is because they do not do that! That is what reflected meters do. Pointing an incident meter at the main light source will make mid-toned things midtones, dark things dark, and light things light when we make a normal print.

This depends on what you are viewing as the main source.

I know it's not classic studio thinking, but I tend to view all of what the camera can see as the main source and the individual lights as simple fractions of that. I do this because this is what the film will see and I want to place subjects in relation to both the film curve and the context of the whole scene.

Turning the meter's head skews the meters relationship to what the camera can see.

 

[Jennychoo]

I agree with everyone

 

[MaximusM3]

Simple test: my deck is now in full shade, while just outside of it, morning sun. I put a subject at the edge of it and metered with my Gossen Digipro F with dome towards the camera (100ISO): reading @ f8 is 1/8. Point the dome towards and close to the subject, reading @ f8 1/15. One stop. Obviously, pointing at the subject is picking up some of the brighter light behind it, which in this case would result in the subject being underexposed by a stop. Now, changing the subject's position a bit, resulted in identical readings. So, in this case, we want the camera to meter what it sees, but we don't want it to expose for the slightly brighter background, which means the dome should be indeed pointed at the camera. Depending on the situations, it's not a bad idea to take multiple readings anyway, with dome inward and outwards, and verify the tests/differences on the negatives/prints.
FWIW, shooting landscapes in even lighting, I have taken readings both ways and, in most cases, they have been identical.

 

[Steve Smith]

I agree with everyone

Neither do I.


Steve.

 

[Marc B.]

Incident readings aren't useful for the zone system though.

Actually, not true.
When you're able to work close to your subject, (as in portraiture), placing your domed meter at various positions around your subject, w/dome facing camera, (especially in shadow areas), will always give better exposure readings, zone system or not.
Incident trumps reflective (even one degree spot), every time. Spot meters main usefulness is for distant subjects where incident is impractical or impossible.

 

[keithwms]

Incident trumps reflective (even one degree spot), every time.

No, not true at all.

The main issue here is reflectivity of the subject. If you are photographing e.g. a metallic object then incident metering can give completely incorrect exposures.

And the zone system can be adapted to any metering technique... or no meter at all.

 

[Marc B.]

The main issue here is reflectivity of the subject.

Keith, please stay on point.
The OP is talking about portraiture, and so am I.

 

[keithwms]

Well I don't buy your generalization for portraiture either. What if your subject has big gold teeth?

 

[Poisson Du Jour]

Okay, I understand why you would use the spot meter and zone system for bw. Especially with landscapes and architecture, for example. I understand that. But, if I am taking a very close up portrait, do I really need to use spot/zone for the skin tone? Why wouldn't an incident meter work the same in this instance? I mean, you are so close, you are certain to be in the same light, unlike far away landscapes. Thoughts?

An incident reading measures light falling on the overall scene from one or more light sources. The problem is that it omits the actual reflected light and does not provide the opportunity to evaluate selective areas of the subject. If the subject is in bright light and shadow, incident will not provide any clue as to tonal range or luminance. Even if you average both extremes, what will the result be do you think? So a more critical method is multi-spot and averaging of the subject which analyses the subject's range of luminances (shadow/highlight) — and this is important if shooting transparency; this is where metering skill is critical in balancing competing illumination by selective analyses. Subject and lighting will also suggest what method you employ.

In studio portraiture, the lighting is often (but not exclusively) very carefully controlled with neither very bright nor very dark areas. Portraits in such conditions can be handled by two ways: incident, by balancing dominant light, and shadow, then averaging; or spot: midtone first (and lock-in), highlight, shadow, average. Either method will require compensation if the subject is very dark or very light (again, you can introduce low- or high-key lighting — the possibilities are endless).

Advanced metering application does require a lot of practice and practical exposues, but once mastered will become second nature. In a professional studio practice it's essential that you work fast and fluently, visualising the result. Of course many people will have their own tried and tested methodologies to pass on and many again take old methods and rrefine them to their own specifics. I suggest you go through all the methods that you can garner with whatever apparatus you are using (LF would require additional work with bellows) and critically assess the results. Experience is a great teacher.


Keith: That is quite a striking — if slightly menacing image — reminiscent of the feared James Bond arch-villains!! It's also a very good example of a subject I would spot meter.

 

[Athiril]

The cases where incident light metering might not give you what you expected is with pure white or pure black objects. Incident light metering abstracts totally from the reflectivity of the subject, but if let's say the subject is very very white, such a reading might place your subject in a zone of the characteristic curve of the film where you don't have much texture.

So when using incident reading with a "milk white" subject, you would close a bit more than what suggested by your light meter. That's probably more true with small format than with MF or LF where film retains more details in the extremes "zones".

That said, with skin tones incident light metering is the best thing because you don't have to worry about the skin tone of the subject: any skin tone will be rendered well.

On the other hand, if it's a model in a wedding dress you are taking pictures of, or with a pure white hat, than, as said above, some caution might be used and some compensation applied.

Fabrizio

PS As ever when talking about precise exposure, what above is mainly true with slide film. If using negative, and especially B&W negative, you have ample overexposure room and you dodge/burn as appropriate during the printing stage.

err incident metering will give the same reading regardless if the object is black or white or grey.

 

[Athiril]

I have never worked in a studio, but I know from experience that Lee knows what he's talking about.

And, incident metering works all the time, regardless of what the lighting is. The key is to meter at the object, pointing the dome to the camera lens opening general direction. The idea is that your meter should see the light that your camera lens is photographing.

It doesn't matter if the object is very bright, very dark, or if it's all mid-tones; the tones will be rendered correctly if you meter this way.

Towards the light source(s) individually, then decide if you wish to expose for key light or whatever. That'll give lighting ratio/contrast ratio between midtones, rather than spot on a white object in the shade, spot on a black object in sun etc.. or vice versa.

Towards the camera is an amalgamation and isn't giving midtones for midtones in X light.