Incident metering of shadows? Sandy King says so

[Regular Rod]

You can make incident readings of shadows even if you don't have a spot meter by looking around for something near you that has a similar value, then meter that.

Okay let's clarify. What are you pointing the meter at when taking one of these "incident" readings please?

RR

 

[Old-N-Feeble]

That's right. It's more accurate, because it takes into account the film and paper curves, both of which have a huge effect on tonal values, while the Zone System as usually presented ignores both.

BTZS does not require use of incident metering. It presents incident metering as a tool that can be useful in many circumstances - more circumstances than many people give it credit for - but it is considered not an exclusive or mandatory tool but rather as complementary to spot metering of reflected light.

Huh?? Not so. Adam's Zone System takes every bit of the process into consideration from film to development to paper to dry-down.

 

[Regular Rod]

Huh?? Not so. Adam's Zone System takes every bit of the process into consideration from film to development to paper to dry-down.

Absolutely... and toning, if used.


RR

 

[MattKing]

In a recent (and still active) thread regarding Barry Thornton's Two Bath developer, a poster linked to an article by Sandy King regarding two-bath development. In that article, Mr King writes:

"Kodak T-MAX 400 was used for this testing. Exposure was determined by a single incident meter reading, taken in the deepest shadows where open detail was desired, with the meter set to box speed of ASA 400. An incident meter reading in the shadows is one of the simplest and most reliable methods of determining exposure for most scenes. Other methods of metering are perfectly acceptable so long as the exposure is sufficient to give texture in the deepest shadows where detail is needed."

This is the first time I have seen it suggested that a photographer, when measuring different light levels in a scene, would use an incident meter to measure the shadows. As an incident meter is not pointed at the subject but rather back at the camera, it has no idea what it is being held in front of -- which, of course, is the point of using an incident meter. I cannot understand how one could measure shadows or highlights with an incident meter?

I suspect this was an error, one of those things where you know what the right word is and yet go ahead and write the opposite. If anyone can explain to me how to go about measuring shadows with an incident meter, I'd be interested to know as I use an incident meter for 99% of my exposures.

The important word in the quote from Sandy King is "in".

The incident meter reading is taken "in" the shadows, not "of" the shadows.

It is a measurement of part of the light illuminating the subject.

Sandy King bases his exposure decisions on that light - seems reasonable.

 

[Old-N-Feeble]

You can make incident readings of shadows even if you don't have a spot meter by looking around for something near you that has a similar value, then meter that.

A meter reading is only accurate if taken in exactly the same lighting condition. Also, what incident meter is as accurate as a direct reading from the object and knowing at what zone to place that object? Take an incident reading while wearing a bright white shirt and surrounded by bright objects... and then take a reading with a black shirt surrounded by very dark objects. Not only that but what are the "important" values of those objects in the shade? Stubbornness never accomplished anything other than self-satisfaction. Use a spot meter for true accuracy.

Use BTZS if that works for you. It's far too imprecise for me.

 

[pdeeh]

markbarendt has written a beautiful primer on incident metering: (there was a url link here which no longer exists)

 

[Old-N-Feeble]

People will believe what they want to believe... including me. I believe there is nothing more accurate than a direct reflected reading from the objects in a scene.

 

[Regular Rod]

People will believe what they want to believe... including me. I believe there is nothing more accurate than a direct reflected reading from the objects in a scene.

Ditto!

RR

 

[Regular Rod]

The important word in the quote from Sandy King is "in".

The incident meter reading is taken "in" the shadows, not "of" the shadows.

It is a measurement of part of the light illuminating the subject.

Sandy King bases his exposure decisions on that light - seems reasonable.

That isn't how shadows or highlights work. Light that is incidentally falling on a subject at a given time has the same luminance all over. The light that lands on shadow areas is mostly absorbed and not reflected back to the camera or the viewer. Only some of the light is reflected back to the camera or viewer and that is the light we should be metering if we want to determine the exposure values for those shadow areas. Incident light readings are of no use unless you want to guess what is and is not Zone III (for example) and reduce the exposure 2 stops from the general (Zone V) reading that is all an incident meter can give you.

RR

 

[Oren Grad]

A meter reading is only accurate if taken in exactly the same lighting condition. Also, what incident meter is as accurate as a direct reading from the object and knowing at what zone to place that object? Take an incident reading while wearing a bright white shirt and surrounded by bright objects... and then take a reading with a black shirt surrounded by very dark objects. Not only that but what are the "important" values of those objects in the shade? Stubbornness never accomplished anything other than self-satisfaction. Use a spot meter for true accuracy.

If the problem is that you are obliged to take a meter reading from a distance, flare in the optics of your spot meter will produce the same kinds of errors. There is no escape from the need to use your judgment about potential measurement confounders.

Use and enjoy the system that suits you. Let's leave it at that, before we all go... :crazy:

 

[cowanw]

Just to be clear, one can take an incident reading out in the sunlight if the subject is in the sun or take a reading while standing in the shade if the subject is in the shade.
And then go from there.
It is not a matter of a exposure value of a shadow area e.g. zone 3

 

[MattKing]

That isn't how shadows or highlights work. Light that is incidentally falling on a subject at a given time has the same luminance all over. The light that lands on shadow areas is mostly absorbed and not reflected back to the camera or the viewer. Only some of the light is reflected back to the camera or viewer and that is the light we should be metering if we want to determine the exposure values for those shadow areas. Incident light readings are of no use unless you want to guess what is and is not Zone III (for example) and reduce the exposure 2 stops from the general (Zone V) reading that is all an incident meter can give you.

RR

Incident meter readings are the only reliable way of measuring the light that falls on the various parts of your subject.

What you do with that measurement depends on your knowledge, experience and the procedure you normally use.

If your normal procedure relies on reflected light readings, you cannot use your normal procedure to make use of incident light measurements.

And if your normal procedure relies on incident light readings, you cannot use your normal procedure to make use of reflected light measurements.

I find incident light readings to be very useful.

 

[Bill Burk]

Bill, thanks for that, your last statement clarified the difference you were speaking to.

I guess I would prefer to do the mental calculations as needed rather than constantly fiddling with the meter's adjustments to get a an appropriate direct reading. I can see the advantage of that method, though.

I also prefer setting the EI once.

I really like Sandy King's article, it's good.

My only criticism is that you have to be careful when following his advice. That's not criticism at all. I'm just cautioning you to be careful not to double-correct for something he's already factored in. If you ALSO choose to use "half box speed"... that would be a double correction.

I just re-read this thread and noticed we haven't directly answered Trask's original question... how do you take an incident reading from the shadows?

You stand in the "shade" and aim the meter at the camera. That assumes there is some shade to stand in. There's lots of advice how to fake it if you can't literally stand in the shade.

 

[Arklatexian]

I also prefer setting the EI once.

I really like Sandy King's article, it's good.

My only criticism is that you have to be careful when following his advice. That's not criticism at all. I'm just cautioning you to be careful not to double-correct for something he's already factored in. If you ALSO choose to use "half box speed"... that would be a double correction.

I just re-read this thread and noticed we haven't directly answered Trask's original question... how do you take an incident reading from the shadows?

You stand in the "shade" and aim the meter at the camera. That assumes there is some shade to stand in. There's lots of advice how to fake it if you can't literally stand in the shade.

It is really amusing how little photography and photographers have changed in the past 30 or 40 years. A dear friend of mine (a professional) and I argued many of these same points in those days, he in favor of incident light meters and me in favor of reflected. The only thing we agreed on was that an incident meter was a quick way to "average" the light FALLING ON the subject. The reflected light meters on the other hand gave more control in exposing to stress shadows or highlights to get something other than a realistic picture for artistic purposes IMHO...Regards

 

[RPC]

My understanding is that incident metering is not designed to average anything, but place an 18% gray, for example at its proper place on the curve, according to the manufacturer, using their rated film speed, and a 75% gray at it's proper place, and a 30% gray at its proper place, and so on. Is this correct? All theoretical, I guess, may not actually happen. Modifications of this, as discussed here, and spot/reflected readings can be be used to change curve placement for whatever reason.

Generally I just use incident readings, based on box speed, then add a stop of exposure. I get good shadow detail without compromising highlights, thanks to latitude of the films. Occasionally I will need reflected.

 

[baachitraka]

Its very simple to adjust the illumination when reading in the shadows, dome facing the camera. But then like other method it needs testing.

 

[John Koehrer]

A meter reading is only accurate if taken in exactly the same lighting condition. Also, what incident meter is as accurate as a direct reading from the object and knowing at what zone to place that object? Take an incident reading while wearing a bright white shirt and surrounded by bright objects... and then take a reading with a black shirt surrounded by very dark objects. Not only that but what are the "important" values of those objects in the shade? Stubbornness never accomplished anything other than self-satisfaction. Use a spot meter for true accuracy.

Use BTZS if that works for you. It's far too imprecise for me.

An incident reading will give you an average reading and you get an average exposure not influenced by the shirt color.

If you meter the white shirt and don't compensate it's gonna be gray in a print. Same with the black shirt. Take your reflected reading and don't compensate, you got a gray shirt.

 

[Xmas]

In a recent (and still active) thread regarding Barry Thornton's Two Bath developer, a poster linked to an article by Sandy King regarding two-bath development. In that article, Mr King writes:

"Kodak T-MAX 400 was used for this testing. Exposure was determined by a single incident meter reading, taken in the deepest shadows where open detail was desired, with the meter set to box speed of ASA 400. An incident meter reading in the shadows is one of the simplest and most reliable methods of determining exposure for most scenes. Other methods of metering are perfectly acceptable so long as the exposure is sufficient to give texture in the deepest shadows where detail is needed."

This is the first time I have seen it suggested that a photographer, when measuring different light levels in a scene, would use an incident meter to measure the shadows. As an incident meter is not pointed at the subject but rather back at the camera, it has no idea what it is being held in front of -- which, of course, is the point of using an incident meter. I cannot understand how one could measure shadows or highlights with an incident meter?

I suspect this was an error, one of those things where you know what the right word is and yet go ahead and write the opposite. If anyone can explain to me how to go about measuring shadows with an incident meter, I'd be interested to know as I use an incident meter for 99% of my exposures.

If you close up to a shadow and

take a reflected or
incident reading with a dome

pointing the meter correctly in each case

And use a zone one setting you get the same exposure for an average subject shadow.

If you can close up to a shadow you don't need a spot meter.

 

[Old-N-Feeble]

I give up. My method is not others' methods and I'm perfectly fine with that.

 

[BrianShaw]

It is really amusing how little photography and photographers have changed in the past 30 or 40 years. A dear friend of mine (a professional) and I argued many of these same points in those days, he in favor of incident light meters and me in favor of reflected. The only thing we agreed on was that an incident meter was a quick way to "average" the light FALLING ON the subject. The reflected light meters on the other hand gave more control in exposing to stress shadows or highlights to get something other than a realistic picture for artistic purposes IMHO...Regards

How true!

 

[Bill Burk]

I give up. My method is not others' methods and I'm perfectly fine with that.

I like to try four different ways and see if I can make them agree. Incident, Spot place shadow, Reflected off palm of hand place Zone VI, Average reflected... Not that I do them all every time, but I choose whatever method is going to work with the meter I have and the light. Only difficult times are those backlit distant scenes when I don't have a spotmeter. Everything else has been easy.

At some point, as I take readings and account for the appropriate "place and fall", I stop tweaking the calculator dial on my meter and that's the reading I take.

Sometimes, I'll have two readings that disagree, then I take the "obviously correct" reading. Sometimes I want "just one more f/stop" and I know since I rate my 400 speed films at 250, I always have about one "safety" stop anyway.

 

[BrianShaw]

I'm very impressed with your highly analytic approach, Bill.

 

[Bill Burk]

Thanks BrianShaw

 

[chiller]

For those that bag incident metering one man's spot metered zone 3 is another man's zone 3 1/2 or zone 2 1/2 so in reality is there such a thing as a real zone 3 consistently in a scene. [I do know there is by the way on a step wedge] Interpretation of what you personally decide is your zone 3 will impact all aspects of your work flow. Use of a spot meter doesn't guarantee correct exposure, it doesn't even guarantee consistency because of flare with the 1 degree spot meter in varying light conditions. Neither does an incident meter unless your system has been fully tested based on how you intend to meter. I personally use Incident metering with BTZS and the ExpoDev but I also have a Pentax 1 degree spot that works equally as well with BTZS.

BTZS testing is much more efficient than Zone system testing because in just five sheet you have all the information you need for full BTZS or the traditional ZS. Even if you don't go as far as running paper tests. Set the ES at 1.05 -1.10 and you will be fine.

When it is all said and done no one should be able to tell how you metered a photograph, either spot or incident, what system you used or even the camera because all are tools for correct exposure.

 

[Steve Smith]

People will believe what they want to believe...

They will. On another forum, we had a long debate about incident metering with many believing that you point the meter dome at the light rather than the camera!


Steve.